| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Sean Christopherson | 3614 | 13.31% | 108 | 12.89% |
| Avi Kivity | 3215 | 11.84% | 46 | 5.49% |
| Paolo Bonzini | 2974 | 10.95% | 77 | 9.19% |
| Maciej S. Szmigiero | 1091 | 4.02% | 8 | 0.95% |
| Chao Peng | 986 | 3.63% | 3 | 0.36% |
| Jing Zhang | 734 | 2.70% | 8 | 0.95% |
| Xiao Guangrong | 695 | 2.56% | 27 | 3.22% |
| Peter Xu | 659 | 2.43% | 13 | 1.55% |
| Marcelo Tosatti | 577 | 2.12% | 24 | 2.86% |
| Janosch Frank | 557 | 2.05% | 1 | 0.12% |
| Gleb Natapov | 499 | 1.84% | 14 | 1.67% |
| David Matlack | 482 | 1.77% | 20 | 2.39% |
| Scott Wood | 459 | 1.69% | 4 | 0.48% |
| Alexander Graf | 446 | 1.64% | 9 | 1.07% |
| Junaid Shahid | 444 | 1.63% | 4 | 0.48% |
| Sheng Yang | 385 | 1.42% | 16 | 1.91% |
| Cornelia Huck | 354 | 1.30% | 2 | 0.24% |
| Wanpeng Li | 332 | 1.22% | 15 | 1.79% |
| Isaku Yamahata | 321 | 1.18% | 3 | 0.36% |
| Sasha Levin | 315 | 1.16% | 3 | 0.36% |
| Vitaly Kuznetsov | 310 | 1.14% | 6 | 0.72% |
| Claudio Imbrenda | 306 | 1.13% | 3 | 0.36% |
| Gregory Haskins | 305 | 1.12% | 6 | 0.72% |
| Xiantao Zhang | 278 | 1.02% | 10 | 1.19% |
| Christoffer Dall | 270 | 0.99% | 11 | 1.31% |
| Marc Zyngier | 238 | 0.88% | 13 | 1.55% |
| KarimAllah Ahmed | 235 | 0.87% | 3 | 0.36% |
| Milan Pandurov | 203 | 0.75% | 1 | 0.12% |
| Izik Eidus | 203 | 0.75% | 10 | 1.19% |
| Carsten Otte | 196 | 0.72% | 5 | 0.60% |
| Mario Smarduch | 189 | 0.70% | 3 | 0.36% |
| Raghavendra K T | 187 | 0.69% | 5 | 0.60% |
| Takuya Yoshikawa | 184 | 0.68% | 17 | 2.03% |
| Gavin Shan | 176 | 0.65% | 3 | 0.36% |
| Arnd Bergmann | 159 | 0.59% | 4 | 0.48% |
| Sergey Senozhatsky | 157 | 0.58% | 2 | 0.24% |
| Christian Bornträger | 147 | 0.54% | 17 | 2.03% |
| Andrew Honig | 145 | 0.53% | 2 | 0.24% |
| Oliver Upton | 143 | 0.53% | 8 | 0.95% |
| Rik Van Riel | 133 | 0.49% | 3 | 0.36% |
| Laurent Vivier | 131 | 0.48% | 2 | 0.24% |
| Ben Gardon | 117 | 0.43% | 8 | 0.95% |
| Suraj Jitindar Singh | 110 | 0.41% | 3 | 0.36% |
| Gal Hammer | 104 | 0.38% | 1 | 0.12% |
| Jan Kiszka | 100 | 0.37% | 7 | 0.84% |
| Joerg Roedel | 100 | 0.37% | 3 | 0.36% |
| Cédric Le Goater | 96 | 0.35% | 2 | 0.24% |
| Qing He | 91 | 0.34% | 1 | 0.12% |
| Andre Przywara | 86 | 0.32% | 3 | 0.36% |
| Dave Hansen | 83 | 0.31% | 2 | 0.24% |
| Will Deacon | 80 | 0.29% | 2 | 0.24% |
| Rusty Russell | 78 | 0.29% | 6 | 0.72% |
| David Hildenbrand | 78 | 0.29% | 6 | 0.72% |
| Weidong Han | 77 | 0.28% | 2 | 0.24% |
| Konstantin Weitz | 76 | 0.28% | 1 | 0.12% |
| Jim Mattson | 74 | 0.27% | 5 | 0.60% |
| David Woodhouse | 74 | 0.27% | 5 | 0.60% |
| Michael S. Tsirkin | 72 | 0.27% | 4 | 0.48% |
| Eddie Dong | 67 | 0.25% | 5 | 0.60% |
| Radim Krčmář | 66 | 0.24% | 6 | 0.72% |
| Vineeth Pillai | 66 | 0.24% | 1 | 0.12% |
| Amos Kong | 64 | 0.24% | 2 | 0.24% |
| Anthony Liguori | 63 | 0.23% | 4 | 0.48% |
| Andrea Arcangeli | 57 | 0.21% | 5 | 0.60% |
| Jan H. Schönherr | 56 | 0.21% | 1 | 0.12% |
| Huang Ying | 54 | 0.20% | 3 | 0.36% |
| Pan Xinhui | 52 | 0.19% | 1 | 0.12% |
| Luiz Fernando N. Capitulino | 51 | 0.19% | 2 | 0.24% |
| Al Viro | 48 | 0.18% | 5 | 0.60% |
| SF Markus Elfring | 46 | 0.17% | 4 | 0.48% |
| Heiko Carstens | 45 | 0.17% | 3 | 0.36% |
| Xiubo Li | 44 | 0.16% | 4 | 0.48% |
| Vipin Sharma | 43 | 0.16% | 1 | 0.12% |
| Michal Luczaj | 40 | 0.15% | 1 | 0.12% |
| Hollis Blanchard | 39 | 0.14% | 5 | 0.60% |
| Nikolay Nikolaev | 36 | 0.13% | 1 | 0.12% |
| Jason (Hui) Wang | 35 | 0.13% | 3 | 0.36% |
| Jay Zhou | 35 | 0.13% | 1 | 0.12% |
| Sanjay Lal | 34 | 0.13% | 1 | 0.12% |
| Christoph Hellwig | 33 | 0.12% | 1 | 0.12% |
| Nicholas Piggin | 32 | 0.12% | 2 | 0.24% |
| Eric Auger | 32 | 0.12% | 1 | 0.12% |
| Igor Mammedov | 32 | 0.12% | 4 | 0.48% |
| Nir Weiner | 32 | 0.12% | 3 | 0.36% |
| Boris Ostrovsky | 31 | 0.11% | 1 | 0.12% |
| Chao Gao | 31 | 0.11% | 2 | 0.24% |
| Rustam Kovhaev | 31 | 0.11% | 2 | 0.24% |
| David L Stevens | 30 | 0.11% | 1 | 0.12% |
| Mingwei Zhang | 29 | 0.11% | 1 | 0.12% |
| Masatake YAMATO | 29 | 0.11% | 1 | 0.12% |
| Tomas Bortoli | 28 | 0.10% | 1 | 0.12% |
| Paul Mackerras | 25 | 0.09% | 4 | 0.48% |
| Lai Jiangshan | 25 | 0.09% | 3 | 0.36% |
| Mike Day | 24 | 0.09% | 1 | 0.12% |
| Thomas Gleixner | 24 | 0.09% | 3 | 0.36% |
| Guang Zeng | 24 | 0.09% | 1 | 0.12% |
| Dan Carpenter | 21 | 0.08% | 3 | 0.36% |
| Nathan Tempelman | 21 | 0.08% | 1 | 0.12% |
| Mark McLoughlin | 21 | 0.08% | 3 | 0.36% |
| Aneesh Kumar K.V | 21 | 0.08% | 1 | 0.12% |
| Alex Williamson | 20 | 0.07% | 6 | 0.72% |
| Ricardo Koller | 19 | 0.07% | 2 | 0.24% |
| Alexey Kardashevskiy | 19 | 0.07% | 1 | 0.12% |
| Zhai, Edwin | 19 | 0.07% | 1 | 0.12% |
| Lan Tianyu | 18 | 0.07% | 3 | 0.36% |
| Dan J Williams | 17 | 0.06% | 1 | 0.12% |
| Denis Efremov | 15 | 0.06% | 1 | 0.12% |
| Anup Patel | 15 | 0.06% | 2 | 0.24% |
| Yi Wang | 14 | 0.05% | 1 | 0.12% |
| Ryan Roberts | 13 | 0.05% | 1 | 0.12% |
| Wei Wang | 13 | 0.05% | 2 | 0.24% |
| Stephen Hemminger | 13 | 0.05% | 1 | 0.12% |
| Breno Leitão | 13 | 0.05% | 1 | 0.12% |
| Mike Waychison | 13 | 0.05% | 1 | 0.12% |
| Maxim Levitsky | 12 | 0.04% | 1 | 0.12% |
| Rafael J. Wysocki | 11 | 0.04% | 1 | 0.12% |
| Alan Cox | 11 | 0.04% | 1 | 0.12% |
| Geliang Tang | 11 | 0.04% | 2 | 0.24% |
| Andres Lagar-Cavilla | 11 | 0.04% | 2 | 0.24% |
| Mathias Krause | 10 | 0.04% | 1 | 0.12% |
| Vladimir Davydov | 10 | 0.04% | 1 | 0.12% |
| Hou Wenlong | 10 | 0.04% | 1 | 0.12% |
| Ingo Molnar | 10 | 0.04% | 4 | 0.48% |
| Lorenzo Stoakes | 10 | 0.04% | 3 | 0.36% |
| Alexey Dobriyan | 9 | 0.03% | 3 | 0.36% |
| Jann Horn | 9 | 0.03% | 1 | 0.12% |
| Souptick Joarder | 9 | 0.03% | 2 | 0.24% |
| Anish Moorthy | 9 | 0.03% | 3 | 0.36% |
| Yang Zhang | 9 | 0.03% | 2 | 0.24% |
| Benjamin Herrenschmidt | 8 | 0.03% | 1 | 0.12% |
| Guo Chao | 8 | 0.03% | 1 | 0.12% |
| Gustavo A. R. Silva | 8 | 0.03% | 1 | 0.12% |
| Ben-Ami Yassour | 7 | 0.03% | 1 | 0.12% |
| Jes Sorensen | 7 | 0.03% | 1 | 0.12% |
| Peter Zijlstra | 7 | 0.03% | 2 | 0.24% |
| Longpeng( Mike) | 6 | 0.02% | 1 | 0.12% |
| Hao Peng | 6 | 0.02% | 1 | 0.12% |
| Yang Bai | 6 | 0.02% | 1 | 0.12% |
| Feng Wu | 6 | 0.02% | 1 | 0.12% |
| Jeff Johnson | 6 | 0.02% | 1 | 0.12% |
| Jérôme Glisse | 6 | 0.02% | 1 | 0.12% |
| Greg Kroah-Hartman | 6 | 0.02% | 2 | 0.24% |
| Michael Müller | 5 | 0.02% | 1 | 0.12% |
| Keqian Zhu | 5 | 0.02% | 1 | 0.12% |
| Leo Yan | 5 | 0.02% | 1 | 0.12% |
| Suravee Suthikulpanit | 5 | 0.02% | 2 | 0.24% |
| Philipp Stanner | 5 | 0.02% | 1 | 0.12% |
| Babu Moger | 5 | 0.02% | 1 | 0.12% |
| ZhuangYanying | 4 | 0.01% | 1 | 0.12% |
| Roman Storozhenko | 4 | 0.01% | 1 | 0.12% |
| Li RongQing | 4 | 0.01% | 2 | 0.24% |
| Wincy Van | 4 | 0.01% | 1 | 0.12% |
| Yann Droneaud | 4 | 0.01% | 1 | 0.12% |
| Wei Yang | 4 | 0.01% | 2 | 0.24% |
| Feng (Eric) Liu | 4 | 0.01% | 1 | 0.12% |
| Darrick J. Wong | 4 | 0.01% | 1 | 0.12% |
| Michel Lespinasse | 4 | 0.01% | 1 | 0.12% |
| Pavel Skripkin | 4 | 0.01% | 1 | 0.12% |
| John Levon | 3 | 0.01% | 1 | 0.12% |
| Jason J. Herne | 3 | 0.01% | 1 | 0.12% |
| Eric W. Biedermann | 3 | 0.01% | 1 | 0.12% |
| Parshuram Sangle | 3 | 0.01% | 1 | 0.12% |
| Li Yang | 3 | 0.01% | 1 | 0.12% |
| Jun Miao | 3 | 0.01% | 1 | 0.12% |
| Steven Price | 3 | 0.01% | 1 | 0.12% |
| Thomas Huth | 3 | 0.01% | 2 | 0.24% |
| Nico Pitre | 3 | 0.01% | 1 | 0.12% |
| Miaohe Lin | 3 | 0.01% | 3 | 0.36% |
| James Morse | 2 | 0.01% | 1 | 0.12% |
| Christoph Lameter | 2 | 0.01% | 1 | 0.12% |
| Stephen Rothwell | 2 | 0.01% | 1 | 0.12% |
| Roland Dreier | 2 | 0.01% | 1 | 0.12% |
| Ulrich Drepper | 2 | 0.01% | 1 | 0.12% |
| Andi Kleen | 2 | 0.01% | 2 | 0.24% |
| Dave Jiang | 2 | 0.01% | 1 | 0.12% |
| Geoff Levand | 2 | 0.01% | 1 | 0.12% |
| Shannon Zhao | 2 | 0.01% | 1 | 0.12% |
| Kai Huang | 2 | 0.01% | 2 | 0.24% |
| Tom Rix | 2 | 0.01% | 1 | 0.12% |
| Andrew Morton | 2 | 0.01% | 1 | 0.12% |
| Davidlohr Bueso A | 2 | 0.01% | 1 | 0.12% |
| Linus Torvalds (pre-git) | 2 | 0.01% | 1 | 0.12% |
| Elena Reshetova | 2 | 0.01% | 1 | 0.12% |
| Uri Lublin | 2 | 0.01% | 1 | 0.12% |
| Linus Torvalds | 2 | 0.01% | 2 | 0.24% |
| Michal Hocko | 2 | 0.01% | 2 | 0.24% |
| Shakeel Butt | 2 | 0.01% | 2 | 0.24% |
| Juergen Gross | 1 | 0.00% | 1 | 0.12% |
| Joe Perches | 1 | 0.00% | 1 | 0.12% |
| Venkatesh Srinivas | 1 | 0.00% | 1 | 0.12% |
| Borislav Petkov | 1 | 0.00% | 1 | 0.12% |
| Jens Freimann | 1 | 0.00% | 1 | 0.12% |
| Liam R. Howlett | 1 | 0.00% | 1 | 0.12% |
| Mark Rutland | 1 | 0.00% | 1 | 0.12% |
| Tom Lendacky | 1 | 0.00% | 1 | 0.12% |
| Tang Chen | 1 | 0.00% | 1 | 0.12% |
| Hamza Mahfooz | 1 | 0.00% | 1 | 0.12% |
| Dominik Dingel | 1 | 0.00% | 1 | 0.12% |
| Yaowei Bai | 1 | 0.00% | 1 | 0.12% |
| Greg Kurz | 1 | 0.00% | 1 | 0.12% |
| Thomas Meyer | 1 | 0.00% | 1 | 0.12% |
| Vegard Nossum | 1 | 0.00% | 1 | 0.12% |
| Fuad Tabba | 1 | 0.00% | 1 | 0.12% |
| Total | 27160 | 838 |
// SPDX-License-Identifier: GPL-2.0-only /* * Kernel-based Virtual Machine (KVM) Hypervisor * * Copyright (C) 2006 Qumranet, Inc. * Copyright 2010 Red Hat, Inc. and/or its affiliates. * * Authors: * Avi Kivity <avi@qumranet.com> * Yaniv Kamay <yaniv@qumranet.com> */ #include <kvm/iodev.h> #include <linux/kvm_host.h> #include <linux/kvm.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/percpu.h> #include <linux/mm.h> #include <linux/miscdevice.h> #include <linux/vmalloc.h> #include <linux/reboot.h> #include <linux/debugfs.h> #include <linux/highmem.h> #include <linux/file.h> #include <linux/syscore_ops.h> #include <linux/cpu.h> #include <linux/sched/signal.h> #include <linux/sched/mm.h> #include <linux/sched/stat.h> #include <linux/cpumask.h> #include <linux/smp.h> #include <linux/anon_inodes.h> #include <linux/profile.h> #include <linux/kvm_para.h> #include <linux/pagemap.h> #include <linux/mman.h> #include <linux/swap.h> #include <linux/bitops.h> #include <linux/spinlock.h> #include <linux/compat.h> #include <linux/srcu.h> #include <linux/hugetlb.h> #include <linux/slab.h> #include <linux/sort.h> #include <linux/bsearch.h> #include <linux/io.h> #include <linux/lockdep.h> #include <linux/kthread.h> #include <linux/suspend.h> #include <asm/processor.h> #include <asm/ioctl.h> #include <linux/uaccess.h> #include "coalesced_mmio.h" #include "async_pf.h" #include "kvm_mm.h" #include "vfio.h" #include <trace/events/ipi.h> #define CREATE_TRACE_POINTS #include <trace/events/kvm.h> #include <linux/kvm_dirty_ring.h> /* Worst case buffer size needed for holding an integer. */ #define ITOA_MAX_LEN 12 MODULE_AUTHOR("Qumranet"); MODULE_DESCRIPTION("Kernel-based Virtual Machine (KVM) Hypervisor"); MODULE_LICENSE("GPL"); /* Architectures should define their poll value according to the halt latency */ unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT; module_param(halt_poll_ns, uint, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns); /* Default doubles per-vcpu halt_poll_ns. */ unsigned int halt_poll_ns_grow = 2; module_param(halt_poll_ns_grow, uint, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns_grow); /* The start value to grow halt_poll_ns from */ unsigned int halt_poll_ns_grow_start = 10000; /* 10us */ module_param(halt_poll_ns_grow_start, uint, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start); /* Default halves per-vcpu halt_poll_ns. */ unsigned int halt_poll_ns_shrink = 2; module_param(halt_poll_ns_shrink, uint, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns_shrink); /* * Ordering of locks: * * kvm->lock --> kvm->slots_lock --> kvm->irq_lock */ DEFINE_MUTEX(kvm_lock); LIST_HEAD(vm_list); static struct kmem_cache *kvm_vcpu_cache; static __read_mostly struct preempt_ops kvm_preempt_ops; static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu); static struct dentry *kvm_debugfs_dir; static const struct file_operations stat_fops_per_vm; static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #ifdef CONFIG_KVM_COMPAT static long kvm_vcpu_compat_ioctl(struct file *file, unsigned int ioctl, unsigned long arg); #define KVM_COMPAT(c) .compat_ioctl = (c) #else /* * For architectures that don't implement a compat infrastructure, * adopt a double line of defense: * - Prevent a compat task from opening /dev/kvm * - If the open has been done by a 64bit task, and the KVM fd * passed to a compat task, let the ioctls fail. */ static long kvm_no_compat_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) { return -EINVAL; } static int kvm_no_compat_open(struct inode *inode, struct file *file) { return is_compat_task() ? -ENODEV : 0; } #define KVM_COMPAT(c) .compat_ioctl = kvm_no_compat_ioctl, \ .open = kvm_no_compat_open #endif static int hardware_enable_all(void); static void hardware_disable_all(void); static void kvm_io_bus_destroy(struct kvm_io_bus *bus); #define KVM_EVENT_CREATE_VM 0 #define KVM_EVENT_DESTROY_VM 1 static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm); static unsigned long long kvm_createvm_count; static unsigned long long kvm_active_vms; static DEFINE_PER_CPU(cpumask_var_t, cpu_kick_mask); __weak void kvm_arch_guest_memory_reclaimed(struct kvm *kvm) { } bool kvm_is_zone_device_page(struct page *page) { /* * The metadata used by is_zone_device_page() to determine whether or * not a page is ZONE_DEVICE is guaranteed to be valid if and only if * the device has been pinned, e.g. by get_user_pages(). WARN if the * page_count() is zero to help detect bad usage of this helper. */ if (WARN_ON_ONCE(!page_count(page))) return false; return is_zone_device_page(page); } /* * Returns a 'struct page' if the pfn is "valid" and backed by a refcounted * page, NULL otherwise. Note, the list of refcounted PG_reserved page types * is likely incomplete, it has been compiled purely through people wanting to * back guest with a certain type of memory and encountering issues. */ struct page *kvm_pfn_to_refcounted_page(kvm_pfn_t pfn) { struct page *page; if (!pfn_valid(pfn)) return NULL; page = pfn_to_page(pfn); if (!PageReserved(page)) return page; /* The ZERO_PAGE(s) is marked PG_reserved, but is refcounted. */ if (is_zero_pfn(pfn)) return page; /* * ZONE_DEVICE pages currently set PG_reserved, but from a refcounting * perspective they are "normal" pages, albeit with slightly different * usage rules. */ if (kvm_is_zone_device_page(page)) return page; return NULL; } /* * Switches to specified vcpu, until a matching vcpu_put() */ void vcpu_load(struct kvm_vcpu *vcpu) { int cpu = get_cpu(); __this_cpu_write(kvm_running_vcpu, vcpu); preempt_notifier_register(&vcpu->preempt_notifier); kvm_arch_vcpu_load(vcpu, cpu); put_cpu(); } EXPORT_SYMBOL_GPL(vcpu_load); void vcpu_put(struct kvm_vcpu *vcpu) { preempt_disable(); kvm_arch_vcpu_put(vcpu); preempt_notifier_unregister(&vcpu->preempt_notifier); __this_cpu_write(kvm_running_vcpu, NULL); preempt_enable(); } EXPORT_SYMBOL_GPL(vcpu_put); /* TODO: merge with kvm_arch_vcpu_should_kick */ static bool kvm_request_needs_ipi(struct kvm_vcpu *vcpu, unsigned req) { int mode = kvm_vcpu_exiting_guest_mode(vcpu); /* * We need to wait for the VCPU to reenable interrupts and get out of * READING_SHADOW_PAGE_TABLES mode. */ if (req & KVM_REQUEST_WAIT) return mode != OUTSIDE_GUEST_MODE; /* * Need to kick a running VCPU, but otherwise there is nothing to do. */ return mode == IN_GUEST_MODE; } static void ack_kick(void *_completed) { } static inline bool kvm_kick_many_cpus(struct cpumask *cpus, bool wait) { if (cpumask_empty(cpus)) return false; smp_call_function_many(cpus, ack_kick, NULL, wait); return true; } static void kvm_make_vcpu_request(struct kvm_vcpu *vcpu, unsigned int req, struct cpumask *tmp, int current_cpu) { int cpu; if (likely(!(req & KVM_REQUEST_NO_ACTION))) __kvm_make_request(req, vcpu); if (!(req & KVM_REQUEST_NO_WAKEUP) && kvm_vcpu_wake_up(vcpu)) return; /* * Note, the vCPU could get migrated to a different pCPU at any point * after kvm_request_needs_ipi(), which could result in sending an IPI * to the previous pCPU. But, that's OK because the purpose of the IPI * is to ensure the vCPU returns to OUTSIDE_GUEST_MODE, which is * satisfied if the vCPU migrates. Entering READING_SHADOW_PAGE_TABLES * after this point is also OK, as the requirement is only that KVM wait * for vCPUs that were reading SPTEs _before_ any changes were * finalized. See kvm_vcpu_kick() for more details on handling requests. */ if (kvm_request_needs_ipi(vcpu, req)) { cpu = READ_ONCE(vcpu->cpu); if (cpu != -1 && cpu != current_cpu) __cpumask_set_cpu(cpu, tmp); } } bool kvm_make_vcpus_request_mask(struct kvm *kvm, unsigned int req, unsigned long *vcpu_bitmap) { struct kvm_vcpu *vcpu; struct cpumask *cpus; int i, me; bool called; me = get_cpu(); cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask); cpumask_clear(cpus); for_each_set_bit(i, vcpu_bitmap, KVM_MAX_VCPUS) { vcpu = kvm_get_vcpu(kvm, i); if (!vcpu) continue; kvm_make_vcpu_request(vcpu, req, cpus, me); } called = kvm_kick_many_cpus(cpus, !!(req & KVM_REQUEST_WAIT)); put_cpu(); return called; } bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req) { struct kvm_vcpu *vcpu; struct cpumask *cpus; unsigned long i; bool called; int me; me = get_cpu(); cpus = this_cpu_cpumask_var_ptr(cpu_kick_mask); cpumask_clear(cpus); kvm_for_each_vcpu(i, vcpu, kvm) kvm_make_vcpu_request(vcpu, req, cpus, me); called = kvm_kick_many_cpus(cpus, !!(req & KVM_REQUEST_WAIT)); put_cpu(); return called; } EXPORT_SYMBOL_GPL(kvm_make_all_cpus_request); void kvm_flush_remote_tlbs(struct kvm *kvm) { ++kvm->stat.generic.remote_tlb_flush_requests; /* * We want to publish modifications to the page tables before reading * mode. Pairs with a memory barrier in arch-specific code. * - x86: smp_mb__after_srcu_read_unlock in vcpu_enter_guest * and smp_mb in walk_shadow_page_lockless_begin/end. * - powerpc: smp_mb in kvmppc_prepare_to_enter. * * There is already an smp_mb__after_atomic() before * kvm_make_all_cpus_request() reads vcpu->mode. We reuse that * barrier here. */ if (!kvm_arch_flush_remote_tlbs(kvm) || kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH)) ++kvm->stat.generic.remote_tlb_flush; } EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs); void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t gfn, u64 nr_pages) { if (!kvm_arch_flush_remote_tlbs_range(kvm, gfn, nr_pages)) return; /* * Fall back to a flushing entire TLBs if the architecture range-based * TLB invalidation is unsupported or can't be performed for whatever * reason. */ kvm_flush_remote_tlbs(kvm); } void kvm_flush_remote_tlbs_memslot(struct kvm *kvm, const struct kvm_memory_slot *memslot) { /* * All current use cases for flushing the TLBs for a specific memslot * are related to dirty logging, and many do the TLB flush out of * mmu_lock. The interaction between the various operations on memslot * must be serialized by slots_locks to ensure the TLB flush from one * operation is observed by any other operation on the same memslot. */ lockdep_assert_held(&kvm->slots_lock); kvm_flush_remote_tlbs_range(kvm, memslot->base_gfn, memslot->npages); } static void kvm_flush_shadow_all(struct kvm *kvm) { kvm_arch_flush_shadow_all(kvm); kvm_arch_guest_memory_reclaimed(kvm); } #ifdef KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE static inline void *mmu_memory_cache_alloc_obj(struct kvm_mmu_memory_cache *mc, gfp_t gfp_flags) { void *page; gfp_flags |= mc->gfp_zero; if (mc->kmem_cache) return kmem_cache_alloc(mc->kmem_cache, gfp_flags); page = (void *)__get_free_page(gfp_flags); if (page && mc->init_value) memset64(page, mc->init_value, PAGE_SIZE / sizeof(u64)); return page; } int __kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int capacity, int min) { gfp_t gfp = mc->gfp_custom ? mc->gfp_custom : GFP_KERNEL_ACCOUNT; void *obj; if (mc->nobjs >= min) return 0; if (unlikely(!mc->objects)) { if (WARN_ON_ONCE(!capacity)) return -EIO; /* * Custom init values can be used only for page allocations, * and obviously conflict with __GFP_ZERO. */ if (WARN_ON_ONCE(mc->init_value && (mc->kmem_cache || mc->gfp_zero))) return -EIO; mc->objects = kvmalloc_array(capacity, sizeof(void *), gfp); if (!mc->objects) return -ENOMEM; mc->capacity = capacity; } /* It is illegal to request a different capacity across topups. */ if (WARN_ON_ONCE(mc->capacity != capacity)) return -EIO; while (mc->nobjs < mc->capacity) { obj = mmu_memory_cache_alloc_obj(mc, gfp); if (!obj) return mc->nobjs >= min ? 0 : -ENOMEM; mc->objects[mc->nobjs++] = obj; } return 0; } int kvm_mmu_topup_memory_cache(struct kvm_mmu_memory_cache *mc, int min) { return __kvm_mmu_topup_memory_cache(mc, KVM_ARCH_NR_OBJS_PER_MEMORY_CACHE, min); } int kvm_mmu_memory_cache_nr_free_objects(struct kvm_mmu_memory_cache *mc) { return mc->nobjs; } void kvm_mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) { while (mc->nobjs) { if (mc->kmem_cache) kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]); else free_page((unsigned long)mc->objects[--mc->nobjs]); } kvfree(mc->objects); mc->objects = NULL; mc->capacity = 0; } void *kvm_mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc) { void *p; if (WARN_ON(!mc->nobjs)) p = mmu_memory_cache_alloc_obj(mc, GFP_ATOMIC | __GFP_ACCOUNT); else p = mc->objects[--mc->nobjs]; BUG_ON(!p); return p; } #endif static void kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) { mutex_init(&vcpu->mutex); vcpu->cpu = -1; vcpu->kvm = kvm; vcpu->vcpu_id = id; vcpu->pid = NULL; #ifndef __KVM_HAVE_ARCH_WQP rcuwait_init(&vcpu->wait); #endif kvm_async_pf_vcpu_init(vcpu); kvm_vcpu_set_in_spin_loop(vcpu, false); kvm_vcpu_set_dy_eligible(vcpu, false); vcpu->preempted = false; vcpu->ready = false; preempt_notifier_init(&vcpu->preempt_notifier, &kvm_preempt_ops); vcpu->last_used_slot = NULL; /* Fill the stats id string for the vcpu */ snprintf(vcpu->stats_id, sizeof(vcpu->stats_id), "kvm-%d/vcpu-%d", task_pid_nr(current), id); } static void kvm_vcpu_destroy(struct kvm_vcpu *vcpu) { kvm_arch_vcpu_destroy(vcpu); kvm_dirty_ring_free(&vcpu->dirty_ring); /* * No need for rcu_read_lock as VCPU_RUN is the only place that changes * the vcpu->pid pointer, and at destruction time all file descriptors * are already gone. */ put_pid(rcu_dereference_protected(vcpu->pid, 1)); free_page((unsigned long)vcpu->run); kmem_cache_free(kvm_vcpu_cache, vcpu); } void kvm_destroy_vcpus(struct kvm *kvm) { unsigned long i; struct kvm_vcpu *vcpu; kvm_for_each_vcpu(i, vcpu, kvm) { kvm_vcpu_destroy(vcpu); xa_erase(&kvm->vcpu_array, i); } atomic_set(&kvm->online_vcpus, 0); } EXPORT_SYMBOL_GPL(kvm_destroy_vcpus); #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn) { return container_of(mn, struct kvm, mmu_notifier); } typedef bool (*gfn_handler_t)(struct kvm *kvm, struct kvm_gfn_range *range); typedef void (*on_lock_fn_t)(struct kvm *kvm); struct kvm_mmu_notifier_range { /* * 64-bit addresses, as KVM notifiers can operate on host virtual * addresses (unsigned long) and guest physical addresses (64-bit). */ u64 start; u64 end; union kvm_mmu_notifier_arg arg; gfn_handler_t handler; on_lock_fn_t on_lock; bool flush_on_ret; bool may_block; }; /* * The inner-most helper returns a tuple containing the return value from the * arch- and action-specific handler, plus a flag indicating whether or not at * least one memslot was found, i.e. if the handler found guest memory. * * Note, most notifiers are averse to booleans, so even though KVM tracks the * return from arch code as a bool, outer helpers will cast it to an int. :-( */ typedef struct kvm_mmu_notifier_return { bool ret; bool found_memslot; } kvm_mn_ret_t; /* * Use a dedicated stub instead of NULL to indicate that there is no callback * function/handler. The compiler technically can't guarantee that a real * function will have a non-zero address, and so it will generate code to * check for !NULL, whereas comparing against a stub will be elided at compile * time (unless the compiler is getting long in the tooth, e.g. gcc 4.9). */ static void kvm_null_fn(void) { } #define IS_KVM_NULL_FN(fn) ((fn) == (void *)kvm_null_fn) /* Iterate over each memslot intersecting [start, last] (inclusive) range */ #define kvm_for_each_memslot_in_hva_range(node, slots, start, last) \ for (node = interval_tree_iter_first(&slots->hva_tree, start, last); \ node; \ node = interval_tree_iter_next(node, start, last)) \ static __always_inline kvm_mn_ret_t __kvm_handle_hva_range(struct kvm *kvm, const struct kvm_mmu_notifier_range *range) { struct kvm_mmu_notifier_return r = { .ret = false, .found_memslot = false, }; struct kvm_gfn_range gfn_range; struct kvm_memory_slot *slot; struct kvm_memslots *slots; int i, idx; if (WARN_ON_ONCE(range->end <= range->start)) return r; /* A null handler is allowed if and only if on_lock() is provided. */ if (WARN_ON_ONCE(IS_KVM_NULL_FN(range->on_lock) && IS_KVM_NULL_FN(range->handler))) return r; idx = srcu_read_lock(&kvm->srcu); for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { struct interval_tree_node *node; slots = __kvm_memslots(kvm, i); kvm_for_each_memslot_in_hva_range(node, slots, range->start, range->end - 1) { unsigned long hva_start, hva_end; slot = container_of(node, struct kvm_memory_slot, hva_node[slots->node_idx]); hva_start = max_t(unsigned long, range->start, slot->userspace_addr); hva_end = min_t(unsigned long, range->end, slot->userspace_addr + (slot->npages << PAGE_SHIFT)); /* * To optimize for the likely case where the address * range is covered by zero or one memslots, don't * bother making these conditional (to avoid writes on * the second or later invocation of the handler). */ gfn_range.arg = range->arg; gfn_range.may_block = range->may_block; /* * {gfn(page) | page intersects with [hva_start, hva_end)} = * {gfn_start, gfn_start+1, ..., gfn_end-1}. */ gfn_range.start = hva_to_gfn_memslot(hva_start, slot); gfn_range.end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, slot); gfn_range.slot = slot; if (!r.found_memslot) { r.found_memslot = true; KVM_MMU_LOCK(kvm); if (!IS_KVM_NULL_FN(range->on_lock)) range->on_lock(kvm); if (IS_KVM_NULL_FN(range->handler)) goto mmu_unlock; } r.ret |= range->handler(kvm, &gfn_range); } } if (range->flush_on_ret && r.ret) kvm_flush_remote_tlbs(kvm); mmu_unlock: if (r.found_memslot) KVM_MMU_UNLOCK(kvm); srcu_read_unlock(&kvm->srcu, idx); return r; } static __always_inline int kvm_handle_hva_range(struct mmu_notifier *mn, unsigned long start, unsigned long end, gfn_handler_t handler) { struct kvm *kvm = mmu_notifier_to_kvm(mn); const struct kvm_mmu_notifier_range range = { .start = start, .end = end, .handler = handler, .on_lock = (void *)kvm_null_fn, .flush_on_ret = true, .may_block = false, }; return __kvm_handle_hva_range(kvm, &range).ret; } static __always_inline int kvm_handle_hva_range_no_flush(struct mmu_notifier *mn, unsigned long start, unsigned long end, gfn_handler_t handler) { struct kvm *kvm = mmu_notifier_to_kvm(mn); const struct kvm_mmu_notifier_range range = { .start = start, .end = end, .handler = handler, .on_lock = (void *)kvm_null_fn, .flush_on_ret = false, .may_block = false, }; return __kvm_handle_hva_range(kvm, &range).ret; } void kvm_mmu_invalidate_begin(struct kvm *kvm) { lockdep_assert_held_write(&kvm->mmu_lock); /* * The count increase must become visible at unlock time as no * spte can be established without taking the mmu_lock and * count is also read inside the mmu_lock critical section. */ kvm->mmu_invalidate_in_progress++; if (likely(kvm->mmu_invalidate_in_progress == 1)) { kvm->mmu_invalidate_range_start = INVALID_GPA; kvm->mmu_invalidate_range_end = INVALID_GPA; } } void kvm_mmu_invalidate_range_add(struct kvm *kvm, gfn_t start, gfn_t end) { lockdep_assert_held_write(&kvm->mmu_lock); WARN_ON_ONCE(!kvm->mmu_invalidate_in_progress); if (likely(kvm->mmu_invalidate_range_start == INVALID_GPA)) { kvm->mmu_invalidate_range_start = start; kvm->mmu_invalidate_range_end = end; } else { /* * Fully tracking multiple concurrent ranges has diminishing * returns. Keep things simple and just find the minimal range * which includes the current and new ranges. As there won't be * enough information to subtract a range after its invalidate * completes, any ranges invalidated concurrently will * accumulate and persist until all outstanding invalidates * complete. */ kvm->mmu_invalidate_range_start = min(kvm->mmu_invalidate_range_start, start); kvm->mmu_invalidate_range_end = max(kvm->mmu_invalidate_range_end, end); } } bool kvm_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) { kvm_mmu_invalidate_range_add(kvm, range->start, range->end); return kvm_unmap_gfn_range(kvm, range); } static int kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, const struct mmu_notifier_range *range) { struct kvm *kvm = mmu_notifier_to_kvm(mn); const struct kvm_mmu_notifier_range hva_range = { .start = range->start, .end = range->end, .handler = kvm_mmu_unmap_gfn_range, .on_lock = kvm_mmu_invalidate_begin, .flush_on_ret = true, .may_block = mmu_notifier_range_blockable(range), }; trace_kvm_unmap_hva_range(range->start, range->end); /* * Prevent memslot modification between range_start() and range_end() * so that conditionally locking provides the same result in both * functions. Without that guarantee, the mmu_invalidate_in_progress * adjustments will be imbalanced. * * Pairs with the decrement in range_end(). */ spin_lock(&kvm->mn_invalidate_lock); kvm->mn_active_invalidate_count++; spin_unlock(&kvm->mn_invalidate_lock); /* * Invalidate pfn caches _before_ invalidating the secondary MMUs, i.e. * before acquiring mmu_lock, to avoid holding mmu_lock while acquiring * each cache's lock. There are relatively few caches in existence at * any given time, and the caches themselves can check for hva overlap, * i.e. don't need to rely on memslot overlap checks for performance. * Because this runs without holding mmu_lock, the pfn caches must use * mn_active_invalidate_count (see above) instead of * mmu_invalidate_in_progress. */ gfn_to_pfn_cache_invalidate_start(kvm, range->start, range->end); /* * If one or more memslots were found and thus zapped, notify arch code * that guest memory has been reclaimed. This needs to be done *after* * dropping mmu_lock, as x86's reclaim path is slooooow. */ if (__kvm_handle_hva_range(kvm, &hva_range).found_memslot) kvm_arch_guest_memory_reclaimed(kvm); return 0; } void kvm_mmu_invalidate_end(struct kvm *kvm) { lockdep_assert_held_write(&kvm->mmu_lock); /* * This sequence increase will notify the kvm page fault that * the page that is going to be mapped in the spte could have * been freed. */ kvm->mmu_invalidate_seq++; smp_wmb(); /* * The above sequence increase must be visible before the * below count decrease, which is ensured by the smp_wmb above * in conjunction with the smp_rmb in mmu_invalidate_retry(). */ kvm->mmu_invalidate_in_progress--; KVM_BUG_ON(kvm->mmu_invalidate_in_progress < 0, kvm); /* * Assert that at least one range was added between start() and end(). * Not adding a range isn't fatal, but it is a KVM bug. */ WARN_ON_ONCE(kvm->mmu_invalidate_range_start == INVALID_GPA); } static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, const struct mmu_notifier_range *range) { struct kvm *kvm = mmu_notifier_to_kvm(mn); const struct kvm_mmu_notifier_range hva_range = { .start = range->start, .end = range->end, .handler = (void *)kvm_null_fn, .on_lock = kvm_mmu_invalidate_end, .flush_on_ret = false, .may_block = mmu_notifier_range_blockable(range), }; bool wake; __kvm_handle_hva_range(kvm, &hva_range); /* Pairs with the increment in range_start(). */ spin_lock(&kvm->mn_invalidate_lock); if (!WARN_ON_ONCE(!kvm->mn_active_invalidate_count)) --kvm->mn_active_invalidate_count; wake = !kvm->mn_active_invalidate_count; spin_unlock(&kvm->mn_invalidate_lock); /* * There can only be one waiter, since the wait happens under * slots_lock. */ if (wake) rcuwait_wake_up(&kvm->mn_memslots_update_rcuwait); } static int kvm_mmu_notifier_clear_flush_young(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end) { trace_kvm_age_hva(start, end); return kvm_handle_hva_range(mn, start, end, kvm_age_gfn); } static int kvm_mmu_notifier_clear_young(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end) { trace_kvm_age_hva(start, end); /* * Even though we do not flush TLB, this will still adversely * affect performance on pre-Haswell Intel EPT, where there is * no EPT Access Bit to clear so that we have to tear down EPT * tables instead. If we find this unacceptable, we can always * add a parameter to kvm_age_hva so that it effectively doesn't * do anything on clear_young. * * Also note that currently we never issue secondary TLB flushes * from clear_young, leaving this job up to the regular system * cadence. If we find this inaccurate, we might come up with a * more sophisticated heuristic later. */ return kvm_handle_hva_range_no_flush(mn, start, end, kvm_age_gfn); } static int kvm_mmu_notifier_test_young(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long address) { trace_kvm_test_age_hva(address); return kvm_handle_hva_range_no_flush(mn, address, address + 1, kvm_test_age_gfn); } static void kvm_mmu_notifier_release(struct mmu_notifier *mn, struct mm_struct *mm) { struct kvm *kvm = mmu_notifier_to_kvm(mn); int idx; idx = srcu_read_lock(&kvm->srcu); kvm_flush_shadow_all(kvm); srcu_read_unlock(&kvm->srcu, idx); } static const struct mmu_notifier_ops kvm_mmu_notifier_ops = { .invalidate_range_start = kvm_mmu_notifier_invalidate_range_start, .invalidate_range_end = kvm_mmu_notifier_invalidate_range_end, .clear_flush_young = kvm_mmu_notifier_clear_flush_young, .clear_young = kvm_mmu_notifier_clear_young, .test_young = kvm_mmu_notifier_test_young, .release = kvm_mmu_notifier_release, }; static int kvm_init_mmu_notifier(struct kvm *kvm) { kvm->mmu_notifier.ops = &kvm_mmu_notifier_ops; return mmu_notifier_register(&kvm->mmu_notifier, current->mm); } #else /* !CONFIG_KVM_GENERIC_MMU_NOTIFIER */ static int kvm_init_mmu_notifier(struct kvm *kvm) { return 0; } #endif /* CONFIG_KVM_GENERIC_MMU_NOTIFIER */ #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER static int kvm_pm_notifier_call(struct notifier_block *bl, unsigned long state, void *unused) { struct kvm *kvm = container_of(bl, struct kvm, pm_notifier); return kvm_arch_pm_notifier(kvm, state); } static void kvm_init_pm_notifier(struct kvm *kvm) { kvm->pm_notifier.notifier_call = kvm_pm_notifier_call; /* Suspend KVM before we suspend ftrace, RCU, etc. */ kvm->pm_notifier.priority = INT_MAX; register_pm_notifier(&kvm->pm_notifier); } static void kvm_destroy_pm_notifier(struct kvm *kvm) { unregister_pm_notifier(&kvm->pm_notifier); } #else /* !CONFIG_HAVE_KVM_PM_NOTIFIER */ static void kvm_init_pm_notifier(struct kvm *kvm) { } static void kvm_destroy_pm_notifier(struct kvm *kvm) { } #endif /* CONFIG_HAVE_KVM_PM_NOTIFIER */ static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot) { if (!memslot->dirty_bitmap) return; vfree(memslot->dirty_bitmap); memslot->dirty_bitmap = NULL; } /* This does not remove the slot from struct kvm_memslots data structures */ static void kvm_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot) { if (slot->flags & KVM_MEM_GUEST_MEMFD) kvm_gmem_unbind(slot); kvm_destroy_dirty_bitmap(slot); kvm_arch_free_memslot(kvm, slot); kfree(slot); } static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots) { struct hlist_node *idnode; struct kvm_memory_slot *memslot; int bkt; /* * The same memslot objects live in both active and inactive sets, * arbitrarily free using index '1' so the second invocation of this * function isn't operating over a structure with dangling pointers * (even though this function isn't actually touching them). */ if (!slots->node_idx) return; hash_for_each_safe(slots->id_hash, bkt, idnode, memslot, id_node[1]) kvm_free_memslot(kvm, memslot); } static umode_t kvm_stats_debugfs_mode(const struct _kvm_stats_desc *pdesc) { switch (pdesc->desc.flags & KVM_STATS_TYPE_MASK) { case KVM_STATS_TYPE_INSTANT: return 0444; case KVM_STATS_TYPE_CUMULATIVE: case KVM_STATS_TYPE_PEAK: default: return 0644; } } static void kvm_destroy_vm_debugfs(struct kvm *kvm) { int i; int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc + kvm_vcpu_stats_header.num_desc; if (IS_ERR(kvm->debugfs_dentry)) return; debugfs_remove_recursive(kvm->debugfs_dentry); if (kvm->debugfs_stat_data) { for (i = 0; i < kvm_debugfs_num_entries; i++) kfree(kvm->debugfs_stat_data[i]); kfree(kvm->debugfs_stat_data); } } static int kvm_create_vm_debugfs(struct kvm *kvm, const char *fdname) { static DEFINE_MUTEX(kvm_debugfs_lock); struct dentry *dent; char dir_name[ITOA_MAX_LEN * 2]; struct kvm_stat_data *stat_data; const struct _kvm_stats_desc *pdesc; int i, ret = -ENOMEM; int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc + kvm_vcpu_stats_header.num_desc; if (!debugfs_initialized()) return 0; snprintf(dir_name, sizeof(dir_name), "%d-%s", task_pid_nr(current), fdname); mutex_lock(&kvm_debugfs_lock); dent = debugfs_lookup(dir_name, kvm_debugfs_dir); if (dent) { pr_warn_ratelimited("KVM: debugfs: duplicate directory %s\n", dir_name); dput(dent); mutex_unlock(&kvm_debugfs_lock); return 0; } dent = debugfs_create_dir(dir_name, kvm_debugfs_dir); mutex_unlock(&kvm_debugfs_lock); if (IS_ERR(dent)) return 0; kvm->debugfs_dentry = dent; kvm->debugfs_stat_data = kcalloc(kvm_debugfs_num_entries, sizeof(*kvm->debugfs_stat_data), GFP_KERNEL_ACCOUNT); if (!kvm->debugfs_stat_data) goto out_err; for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) { pdesc = &kvm_vm_stats_desc[i]; stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT); if (!stat_data) goto out_err; stat_data->kvm = kvm; stat_data->desc = pdesc; stat_data->kind = KVM_STAT_VM; kvm->debugfs_stat_data[i] = stat_data; debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc), kvm->debugfs_dentry, stat_data, &stat_fops_per_vm); } for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) { pdesc = &kvm_vcpu_stats_desc[i]; stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT); if (!stat_data) goto out_err; stat_data->kvm = kvm; stat_data->desc = pdesc; stat_data->kind = KVM_STAT_VCPU; kvm->debugfs_stat_data[i + kvm_vm_stats_header.num_desc] = stat_data; debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc), kvm->debugfs_dentry, stat_data, &stat_fops_per_vm); } kvm_arch_create_vm_debugfs(kvm); return 0; out_err: kvm_destroy_vm_debugfs(kvm); return ret; } /* * Called after the VM is otherwise initialized, but just before adding it to * the vm_list. */ int __weak kvm_arch_post_init_vm(struct kvm *kvm) { return 0; } /* * Called just after removing the VM from the vm_list, but before doing any * other destruction. */ void __weak kvm_arch_pre_destroy_vm(struct kvm *kvm) { } /* * Called after per-vm debugfs created. When called kvm->debugfs_dentry should * be setup already, so we can create arch-specific debugfs entries under it. * Cleanup should be automatic done in kvm_destroy_vm_debugfs() recursively, so * a per-arch destroy interface is not needed. */ void __weak kvm_arch_create_vm_debugfs(struct kvm *kvm) { } static struct kvm *kvm_create_vm(unsigned long type, const char *fdname) { struct kvm *kvm = kvm_arch_alloc_vm(); struct kvm_memslots *slots; int r, i, j; if (!kvm) return ERR_PTR(-ENOMEM); KVM_MMU_LOCK_INIT(kvm); mmgrab(current->mm); kvm->mm = current->mm; kvm_eventfd_init(kvm); mutex_init(&kvm->lock); mutex_init(&kvm->irq_lock); mutex_init(&kvm->slots_lock); mutex_init(&kvm->slots_arch_lock); spin_lock_init(&kvm->mn_invalidate_lock); rcuwait_init(&kvm->mn_memslots_update_rcuwait); xa_init(&kvm->vcpu_array); #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES xa_init(&kvm->mem_attr_array); #endif INIT_LIST_HEAD(&kvm->gpc_list); spin_lock_init(&kvm->gpc_lock); INIT_LIST_HEAD(&kvm->devices); kvm->max_vcpus = KVM_MAX_VCPUS; BUILD_BUG_ON(KVM_MEM_SLOTS_NUM > SHRT_MAX); /* * Force subsequent debugfs file creations to fail if the VM directory * is not created (by kvm_create_vm_debugfs()). */ kvm->debugfs_dentry = ERR_PTR(-ENOENT); snprintf(kvm->stats_id, sizeof(kvm->stats_id), "kvm-%d", task_pid_nr(current)); r = -ENOMEM; if (init_srcu_struct(&kvm->srcu)) goto out_err_no_srcu; if (init_srcu_struct(&kvm->irq_srcu)) goto out_err_no_irq_srcu; r = kvm_init_irq_routing(kvm); if (r) goto out_err_no_irq_routing; refcount_set(&kvm->users_count, 1); for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { for (j = 0; j < 2; j++) { slots = &kvm->__memslots[i][j]; atomic_long_set(&slots->last_used_slot, (unsigned long)NULL); slots->hva_tree = RB_ROOT_CACHED; slots->gfn_tree = RB_ROOT; hash_init(slots->id_hash); slots->node_idx = j; /* Generations must be different for each address space. */ slots->generation = i; } rcu_assign_pointer(kvm->memslots[i], &kvm->__memslots[i][0]); } r = -ENOMEM; for (i = 0; i < KVM_NR_BUSES; i++) { rcu_assign_pointer(kvm->buses[i], kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT)); if (!kvm->buses[i]) goto out_err_no_arch_destroy_vm; } r = kvm_arch_init_vm(kvm, type); if (r) goto out_err_no_arch_destroy_vm; r = hardware_enable_all(); if (r) goto out_err_no_disable; #ifdef CONFIG_HAVE_KVM_IRQCHIP INIT_HLIST_HEAD(&kvm->irq_ack_notifier_list); #endif r = kvm_init_mmu_notifier(kvm); if (r) goto out_err_no_mmu_notifier; r = kvm_coalesced_mmio_init(kvm); if (r < 0) goto out_no_coalesced_mmio; r = kvm_create_vm_debugfs(kvm, fdname); if (r) goto out_err_no_debugfs; r = kvm_arch_post_init_vm(kvm); if (r) goto out_err; mutex_lock(&kvm_lock); list_add(&kvm->vm_list, &vm_list); mutex_unlock(&kvm_lock); preempt_notifier_inc(); kvm_init_pm_notifier(kvm); return kvm; out_err: kvm_destroy_vm_debugfs(kvm); out_err_no_debugfs: kvm_coalesced_mmio_free(kvm); out_no_coalesced_mmio: #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER if (kvm->mmu_notifier.ops) mmu_notifier_unregister(&kvm->mmu_notifier, current->mm); #endif out_err_no_mmu_notifier: hardware_disable_all(); out_err_no_disable: kvm_arch_destroy_vm(kvm); out_err_no_arch_destroy_vm: WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count)); for (i = 0; i < KVM_NR_BUSES; i++) kfree(kvm_get_bus(kvm, i)); kvm_free_irq_routing(kvm); out_err_no_irq_routing: cleanup_srcu_struct(&kvm->irq_srcu); out_err_no_irq_srcu: cleanup_srcu_struct(&kvm->srcu); out_err_no_srcu: kvm_arch_free_vm(kvm); mmdrop(current->mm); return ERR_PTR(r); } static void kvm_destroy_devices(struct kvm *kvm) { struct kvm_device *dev, *tmp; /* * We do not need to take the kvm->lock here, because nobody else * has a reference to the struct kvm at this point and therefore * cannot access the devices list anyhow. * * The device list is generally managed as an rculist, but list_del() * is used intentionally here. If a bug in KVM introduced a reader that * was not backed by a reference on the kvm struct, the hope is that * it'd consume the poisoned forward pointer instead of suffering a * use-after-free, even though this cannot be guaranteed. */ list_for_each_entry_safe(dev, tmp, &kvm->devices, vm_node) { list_del(&dev->vm_node); dev->ops->destroy(dev); } } static void kvm_destroy_vm(struct kvm *kvm) { int i; struct mm_struct *mm = kvm->mm; kvm_destroy_pm_notifier(kvm); kvm_uevent_notify_change(KVM_EVENT_DESTROY_VM, kvm); kvm_destroy_vm_debugfs(kvm); kvm_arch_sync_events(kvm); mutex_lock(&kvm_lock); list_del(&kvm->vm_list); mutex_unlock(&kvm_lock); kvm_arch_pre_destroy_vm(kvm); kvm_free_irq_routing(kvm); for (i = 0; i < KVM_NR_BUSES; i++) { struct kvm_io_bus *bus = kvm_get_bus(kvm, i); if (bus) kvm_io_bus_destroy(bus); kvm->buses[i] = NULL; } kvm_coalesced_mmio_free(kvm); #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm); /* * At this point, pending calls to invalidate_range_start() * have completed but no more MMU notifiers will run, so * mn_active_invalidate_count may remain unbalanced. * No threads can be waiting in kvm_swap_active_memslots() as the * last reference on KVM has been dropped, but freeing * memslots would deadlock without this manual intervention. * * If the count isn't unbalanced, i.e. KVM did NOT unregister its MMU * notifier between a start() and end(), then there shouldn't be any * in-progress invalidations. */ WARN_ON(rcuwait_active(&kvm->mn_memslots_update_rcuwait)); if (kvm->mn_active_invalidate_count) kvm->mn_active_invalidate_count = 0; else WARN_ON(kvm->mmu_invalidate_in_progress); #else kvm_flush_shadow_all(kvm); #endif kvm_arch_destroy_vm(kvm); kvm_destroy_devices(kvm); for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { kvm_free_memslots(kvm, &kvm->__memslots[i][0]); kvm_free_memslots(kvm, &kvm->__memslots[i][1]); } cleanup_srcu_struct(&kvm->irq_srcu); cleanup_srcu_struct(&kvm->srcu); #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES xa_destroy(&kvm->mem_attr_array); #endif kvm_arch_free_vm(kvm); preempt_notifier_dec(); hardware_disable_all(); mmdrop(mm); } void kvm_get_kvm(struct kvm *kvm) { refcount_inc(&kvm->users_count); } EXPORT_SYMBOL_GPL(kvm_get_kvm); /* * Make sure the vm is not during destruction, which is a safe version of * kvm_get_kvm(). Return true if kvm referenced successfully, false otherwise. */ bool kvm_get_kvm_safe(struct kvm *kvm) { return refcount_inc_not_zero(&kvm->users_count); } EXPORT_SYMBOL_GPL(kvm_get_kvm_safe); void kvm_put_kvm(struct kvm *kvm) { if (refcount_dec_and_test(&kvm->users_count)) kvm_destroy_vm(kvm); } EXPORT_SYMBOL_GPL(kvm_put_kvm); /* * Used to put a reference that was taken on behalf of an object associated * with a user-visible file descriptor, e.g. a vcpu or device, if installation * of the new file descriptor fails and the reference cannot be transferred to * its final owner. In such cases, the caller is still actively using @kvm and * will fail miserably if the refcount unexpectedly hits zero. */ void kvm_put_kvm_no_destroy(struct kvm *kvm) { WARN_ON(refcount_dec_and_test(&kvm->users_count)); } EXPORT_SYMBOL_GPL(kvm_put_kvm_no_destroy); static int kvm_vm_release(struct inode *inode, struct file *filp) { struct kvm *kvm = filp->private_data; kvm_irqfd_release(kvm); kvm_put_kvm(kvm); return 0; } /* * Allocation size is twice as large as the actual dirty bitmap size. * See kvm_vm_ioctl_get_dirty_log() why this is needed. */ static int kvm_alloc_dirty_bitmap(struct kvm_memory_slot *memslot) { unsigned long dirty_bytes = kvm_dirty_bitmap_bytes(memslot); memslot->dirty_bitmap = __vcalloc(2, dirty_bytes, GFP_KERNEL_ACCOUNT); if (!memslot->dirty_bitmap) return -ENOMEM; return 0; } static struct kvm_memslots *kvm_get_inactive_memslots(struct kvm *kvm, int as_id) { struct kvm_memslots *active = __kvm_memslots(kvm, as_id); int node_idx_inactive = active->node_idx ^ 1; return &kvm->__memslots[as_id][node_idx_inactive]; } /* * Helper to get the address space ID when one of memslot pointers may be NULL. * This also serves as a sanity that at least one of the pointers is non-NULL, * and that their address space IDs don't diverge. */ static int kvm_memslots_get_as_id(struct kvm_memory_slot *a, struct kvm_memory_slot *b) { if (WARN_ON_ONCE(!a && !b)) return 0; if (!a) return b->as_id; if (!b) return a->as_id; WARN_ON_ONCE(a->as_id != b->as_id); return a->as_id; } static void kvm_insert_gfn_node(struct kvm_memslots *slots, struct kvm_memory_slot *slot) { struct rb_root *gfn_tree = &slots->gfn_tree; struct rb_node **node, *parent; int idx = slots->node_idx; parent = NULL; for (node = &gfn_tree->rb_node; *node; ) { struct kvm_memory_slot *tmp; tmp = container_of(*node, struct kvm_memory_slot, gfn_node[idx]); parent = *node; if (slot->base_gfn < tmp->base_gfn) node = &(*node)->rb_left; else if (slot->base_gfn > tmp->base_gfn) node = &(*node)->rb_right; else BUG(); } rb_link_node(&slot->gfn_node[idx], parent, node); rb_insert_color(&slot->gfn_node[idx], gfn_tree); } static void kvm_erase_gfn_node(struct kvm_memslots *slots, struct kvm_memory_slot *slot) { rb_erase(&slot->gfn_node[slots->node_idx], &slots->gfn_tree); } static void kvm_replace_gfn_node(struct kvm_memslots *slots, struct kvm_memory_slot *old, struct kvm_memory_slot *new) { int idx = slots->node_idx; WARN_ON_ONCE(old->base_gfn != new->base_gfn); rb_replace_node(&old->gfn_node[idx], &new->gfn_node[idx], &slots->gfn_tree); } /* * Replace @old with @new in the inactive memslots. * * With NULL @old this simply adds @new. * With NULL @new this simply removes @old. * * If @new is non-NULL its hva_node[slots_idx] range has to be set * appropriately. */ static void kvm_replace_memslot(struct kvm *kvm, struct kvm_memory_slot *old, struct kvm_memory_slot *new) { int as_id = kvm_memslots_get_as_id(old, new); struct kvm_memslots *slots = kvm_get_inactive_memslots(kvm, as_id); int idx = slots->node_idx; if (old) { hash_del(&old->id_node[idx]); interval_tree_remove(&old->hva_node[idx], &slots->hva_tree); if ((long)old == atomic_long_read(&slots->last_used_slot)) atomic_long_set(&slots->last_used_slot, (long)new); if (!new) { kvm_erase_gfn_node(slots, old); return; } } /* * Initialize @new's hva range. Do this even when replacing an @old * slot, kvm_copy_memslot() deliberately does not touch node data. */ new->hva_node[idx].start = new->userspace_addr; new->hva_node[idx].last = new->userspace_addr + (new->npages << PAGE_SHIFT) - 1; /* * (Re)Add the new memslot. There is no O(1) interval_tree_replace(), * hva_node needs to be swapped with remove+insert even though hva can't * change when replacing an existing slot. */ hash_add(slots->id_hash, &new->id_node[idx], new->id); interval_tree_insert(&new->hva_node[idx], &slots->hva_tree); /* * If the memslot gfn is unchanged, rb_replace_node() can be used to * switch the node in the gfn tree instead of removing the old and * inserting the new as two separate operations. Replacement is a * single O(1) operation versus two O(log(n)) operations for * remove+insert. */ if (old && old->base_gfn == new->base_gfn) { kvm_replace_gfn_node(slots, old, new); } else { if (old) kvm_erase_gfn_node(slots, old); kvm_insert_gfn_node(slots, new); } } /* * Flags that do not access any of the extra space of struct * kvm_userspace_memory_region2. KVM_SET_USER_MEMORY_REGION_V1_FLAGS * only allows these. */ #define KVM_SET_USER_MEMORY_REGION_V1_FLAGS \ (KVM_MEM_LOG_DIRTY_PAGES | KVM_MEM_READONLY) static int check_memory_region_flags(struct kvm *kvm, const struct kvm_userspace_memory_region2 *mem) { u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES; if (kvm_arch_has_private_mem(kvm)) valid_flags |= KVM_MEM_GUEST_MEMFD; /* Dirty logging private memory is not currently supported. */ if (mem->flags & KVM_MEM_GUEST_MEMFD) valid_flags &= ~KVM_MEM_LOG_DIRTY_PAGES; /* * GUEST_MEMFD is incompatible with read-only memslots, as writes to * read-only memslots have emulated MMIO, not page fault, semantics, * and KVM doesn't allow emulated MMIO for private memory. */ if (kvm_arch_has_readonly_mem(kvm) && !(mem->flags & KVM_MEM_GUEST_MEMFD)) valid_flags |= KVM_MEM_READONLY; if (mem->flags & ~valid_flags) return -EINVAL; return 0; } static void kvm_swap_active_memslots(struct kvm *kvm, int as_id) { struct kvm_memslots *slots = kvm_get_inactive_memslots(kvm, as_id); /* Grab the generation from the activate memslots. */ u64 gen = __kvm_memslots(kvm, as_id)->generation; WARN_ON(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); slots->generation = gen | KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS; /* * Do not store the new memslots while there are invalidations in * progress, otherwise the locking in invalidate_range_start and * invalidate_range_end will be unbalanced. */ spin_lock(&kvm->mn_invalidate_lock); prepare_to_rcuwait(&kvm->mn_memslots_update_rcuwait); while (kvm->mn_active_invalidate_count) { set_current_state(TASK_UNINTERRUPTIBLE); spin_unlock(&kvm->mn_invalidate_lock); schedule(); spin_lock(&kvm->mn_invalidate_lock); } finish_rcuwait(&kvm->mn_memslots_update_rcuwait); rcu_assign_pointer(kvm->memslots[as_id], slots); spin_unlock(&kvm->mn_invalidate_lock); /* * Acquired in kvm_set_memslot. Must be released before synchronize * SRCU below in order to avoid deadlock with another thread * acquiring the slots_arch_lock in an srcu critical section. */ mutex_unlock(&kvm->slots_arch_lock); synchronize_srcu_expedited(&kvm->srcu); /* * Increment the new memslot generation a second time, dropping the * update in-progress flag and incrementing the generation based on * the number of address spaces. This provides a unique and easily * identifiable generation number while the memslots are in flux. */ gen = slots->generation & ~KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS; /* * Generations must be unique even across address spaces. We do not need * a global counter for that, instead the generation space is evenly split * across address spaces. For example, with two address spaces, address * space 0 will use generations 0, 2, 4, ... while address space 1 will * use generations 1, 3, 5, ... */ gen += kvm_arch_nr_memslot_as_ids(kvm); kvm_arch_memslots_updated(kvm, gen); slots->generation = gen; } static int kvm_prepare_memory_region(struct kvm *kvm, const struct kvm_memory_slot *old, struct kvm_memory_slot *new, enum kvm_mr_change change) { int r; /* * If dirty logging is disabled, nullify the bitmap; the old bitmap * will be freed on "commit". If logging is enabled in both old and * new, reuse the existing bitmap. If logging is enabled only in the * new and KVM isn't using a ring buffer, allocate and initialize a * new bitmap. */ if (change != KVM_MR_DELETE) { if (!(new->flags & KVM_MEM_LOG_DIRTY_PAGES)) new->dirty_bitmap = NULL; else if (old && old->dirty_bitmap) new->dirty_bitmap = old->dirty_bitmap; else if (kvm_use_dirty_bitmap(kvm)) { r = kvm_alloc_dirty_bitmap(new); if (r) return r; if (kvm_dirty_log_manual_protect_and_init_set(kvm)) bitmap_set(new->dirty_bitmap, 0, new->npages); } } r = kvm_arch_prepare_memory_region(kvm, old, new, change); /* Free the bitmap on failure if it was allocated above. */ if (r && new && new->dirty_bitmap && (!old || !old->dirty_bitmap)) kvm_destroy_dirty_bitmap(new); return r; } static void kvm_commit_memory_region(struct kvm *kvm, struct kvm_memory_slot *old, const struct kvm_memory_slot *new, enum kvm_mr_change change) { int old_flags = old ? old->flags : 0; int new_flags = new ? new->flags : 0; /* * Update the total number of memslot pages before calling the arch * hook so that architectures can consume the result directly. */ if (change == KVM_MR_DELETE) kvm->nr_memslot_pages -= old->npages; else if (change == KVM_MR_CREATE) kvm->nr_memslot_pages += new->npages; if ((old_flags ^ new_flags) & KVM_MEM_LOG_DIRTY_PAGES) { int change = (new_flags & KVM_MEM_LOG_DIRTY_PAGES) ? 1 : -1; atomic_set(&kvm->nr_memslots_dirty_logging, atomic_read(&kvm->nr_memslots_dirty_logging) + change); } kvm_arch_commit_memory_region(kvm, old, new, change); switch (change) { case KVM_MR_CREATE: /* Nothing more to do. */ break; case KVM_MR_DELETE: /* Free the old memslot and all its metadata. */ kvm_free_memslot(kvm, old); break; case KVM_MR_MOVE: case KVM_MR_FLAGS_ONLY: /* * Free the dirty bitmap as needed; the below check encompasses * both the flags and whether a ring buffer is being used) */ if (old->dirty_bitmap && !new->dirty_bitmap) kvm_destroy_dirty_bitmap(old); /* * The final quirk. Free the detached, old slot, but only its * memory, not any metadata. Metadata, including arch specific * data, may be reused by @new. */ kfree(old); break; default: BUG(); } } /* * Activate @new, which must be installed in the inactive slots by the caller, * by swapping the active slots and then propagating @new to @old once @old is * unreachable and can be safely modified. * * With NULL @old this simply adds @new to @active (while swapping the sets). * With NULL @new this simply removes @old from @active and frees it * (while also swapping the sets). */ static void kvm_activate_memslot(struct kvm *kvm, struct kvm_memory_slot *old, struct kvm_memory_slot *new) { int as_id = kvm_memslots_get_as_id(old, new); kvm_swap_active_memslots(kvm, as_id); /* Propagate the new memslot to the now inactive memslots. */ kvm_replace_memslot(kvm, old, new); } static void kvm_copy_memslot(struct kvm_memory_slot *dest, const struct kvm_memory_slot *src) { dest->base_gfn = src->base_gfn; dest->npages = src->npages; dest->dirty_bitmap = src->dirty_bitmap; dest->arch = src->arch; dest->userspace_addr = src->userspace_addr; dest->flags = src->flags; dest->id = src->id; dest->as_id = src->as_id; } static void kvm_invalidate_memslot(struct kvm *kvm, struct kvm_memory_slot *old, struct kvm_memory_slot *invalid_slot) { /* * Mark the current slot INVALID. As with all memslot modifications, * this must be done on an unreachable slot to avoid modifying the * current slot in the active tree. */ kvm_copy_memslot(invalid_slot, old); invalid_slot->flags |= KVM_MEMSLOT_INVALID; kvm_replace_memslot(kvm, old, invalid_slot); /* * Activate the slot that is now marked INVALID, but don't propagate * the slot to the now inactive slots. The slot is either going to be * deleted or recreated as a new slot. */ kvm_swap_active_memslots(kvm, old->as_id); /* * From this point no new shadow pages pointing to a deleted, or moved, * memslot will be created. Validation of sp->gfn happens in: * - gfn_to_hva (kvm_read_guest, gfn_to_pfn) * - kvm_is_visible_gfn (mmu_check_root) */ kvm_arch_flush_shadow_memslot(kvm, old); kvm_arch_guest_memory_reclaimed(kvm); /* Was released by kvm_swap_active_memslots(), reacquire. */ mutex_lock(&kvm->slots_arch_lock); /* * Copy the arch-specific field of the newly-installed slot back to the * old slot as the arch data could have changed between releasing * slots_arch_lock in kvm_swap_active_memslots() and re-acquiring the lock * above. Writers are required to retrieve memslots *after* acquiring * slots_arch_lock, thus the active slot's data is guaranteed to be fresh. */ old->arch = invalid_slot->arch; } static void kvm_create_memslot(struct kvm *kvm, struct kvm_memory_slot *new) { /* Add the new memslot to the inactive set and activate. */ kvm_replace_memslot(kvm, NULL, new); kvm_activate_memslot(kvm, NULL, new); } static void kvm_delete_memslot(struct kvm *kvm, struct kvm_memory_slot *old, struct kvm_memory_slot *invalid_slot) { /* * Remove the old memslot (in the inactive memslots) by passing NULL as * the "new" slot, and for the invalid version in the active slots. */ kvm_replace_memslot(kvm, old, NULL); kvm_activate_memslot(kvm, invalid_slot, NULL); } static void kvm_move_memslot(struct kvm *kvm, struct kvm_memory_slot *old, struct kvm_memory_slot *new, struct kvm_memory_slot *invalid_slot) { /* * Replace the old memslot in the inactive slots, and then swap slots * and replace the current INVALID with the new as well. */ kvm_replace_memslot(kvm, old, new); kvm_activate_memslot(kvm, invalid_slot, new); } static void kvm_update_flags_memslot(struct kvm *kvm, struct kvm_memory_slot *old, struct kvm_memory_slot *new) { /* * Similar to the MOVE case, but the slot doesn't need to be zapped as * an intermediate step. Instead, the old memslot is simply replaced * with a new, updated copy in both memslot sets. */ kvm_replace_memslot(kvm, old, new); kvm_activate_memslot(kvm, old, new); } static int kvm_set_memslot(struct kvm *kvm, struct kvm_memory_slot *old, struct kvm_memory_slot *new, enum kvm_mr_change change) { struct kvm_memory_slot *invalid_slot; int r; /* * Released in kvm_swap_active_memslots(). * * Must be held from before the current memslots are copied until after * the new memslots are installed with rcu_assign_pointer, then * released before the synchronize srcu in kvm_swap_active_memslots(). * * When modifying memslots outside of the slots_lock, must be held * before reading the pointer to the current memslots until after all * changes to those memslots are complete. * * These rules ensure that installing new memslots does not lose * changes made to the previous memslots. */ mutex_lock(&kvm->slots_arch_lock); /* * Invalidate the old slot if it's being deleted or moved. This is * done prior to actually deleting/moving the memslot to allow vCPUs to * continue running by ensuring there are no mappings or shadow pages * for the memslot when it is deleted/moved. Without pre-invalidation * (and without a lock), a window would exist between effecting the * delete/move and committing the changes in arch code where KVM or a * guest could access a non-existent memslot. * * Modifications are done on a temporary, unreachable slot. The old * slot needs to be preserved in case a later step fails and the * invalidation needs to be reverted. */ if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) { invalid_slot = kzalloc(sizeof(*invalid_slot), GFP_KERNEL_ACCOUNT); if (!invalid_slot) { mutex_unlock(&kvm->slots_arch_lock); return -ENOMEM; } kvm_invalidate_memslot(kvm, old, invalid_slot); } r = kvm_prepare_memory_region(kvm, old, new, change); if (r) { /* * For DELETE/MOVE, revert the above INVALID change. No * modifications required since the original slot was preserved * in the inactive slots. Changing the active memslots also * release slots_arch_lock. */ if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) { kvm_activate_memslot(kvm, invalid_slot, old); kfree(invalid_slot); } else { mutex_unlock(&kvm->slots_arch_lock); } return r; } /* * For DELETE and MOVE, the working slot is now active as the INVALID * version of the old slot. MOVE is particularly special as it reuses * the old slot and returns a copy of the old slot (in working_slot). * For CREATE, there is no old slot. For DELETE and FLAGS_ONLY, the * old slot is detached but otherwise preserved. */ if (change == KVM_MR_CREATE) kvm_create_memslot(kvm, new); else if (change == KVM_MR_DELETE) kvm_delete_memslot(kvm, old, invalid_slot); else if (change == KVM_MR_MOVE) kvm_move_memslot(kvm, old, new, invalid_slot); else if (change == KVM_MR_FLAGS_ONLY) kvm_update_flags_memslot(kvm, old, new); else BUG(); /* Free the temporary INVALID slot used for DELETE and MOVE. */ if (change == KVM_MR_DELETE || change == KVM_MR_MOVE) kfree(invalid_slot); /* * No need to refresh new->arch, changes after dropping slots_arch_lock * will directly hit the final, active memslot. Architectures are * responsible for knowing that new->arch may be stale. */ kvm_commit_memory_region(kvm, old, new, change); return 0; } static bool kvm_check_memslot_overlap(struct kvm_memslots *slots, int id, gfn_t start, gfn_t end) { struct kvm_memslot_iter iter; kvm_for_each_memslot_in_gfn_range(&iter, slots, start, end) { if (iter.slot->id != id) return true; } return false; } /* * Allocate some memory and give it an address in the guest physical address * space. * * Discontiguous memory is allowed, mostly for framebuffers. * * Must be called holding kvm->slots_lock for write. */ int __kvm_set_memory_region(struct kvm *kvm, const struct kvm_userspace_memory_region2 *mem) { struct kvm_memory_slot *old, *new; struct kvm_memslots *slots; enum kvm_mr_change change; unsigned long npages; gfn_t base_gfn; int as_id, id; int r; r = check_memory_region_flags(kvm, mem); if (r) return r; as_id = mem->slot >> 16; id = (u16)mem->slot; /* General sanity checks */ if ((mem->memory_size & (PAGE_SIZE - 1)) || (mem->memory_size != (unsigned long)mem->memory_size)) return -EINVAL; if (mem->guest_phys_addr & (PAGE_SIZE - 1)) return -EINVAL; /* We can read the guest memory with __xxx_user() later on. */ if ((mem->userspace_addr & (PAGE_SIZE - 1)) || (mem->userspace_addr != untagged_addr(mem->userspace_addr)) || !access_ok((void __user *)(unsigned long)mem->userspace_addr, mem->memory_size)) return -EINVAL; if (mem->flags & KVM_MEM_GUEST_MEMFD && (mem->guest_memfd_offset & (PAGE_SIZE - 1) || mem->guest_memfd_offset + mem->memory_size < mem->guest_memfd_offset)) return -EINVAL; if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_MEM_SLOTS_NUM) return -EINVAL; if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) return -EINVAL; if ((mem->memory_size >> PAGE_SHIFT) > KVM_MEM_MAX_NR_PAGES) return -EINVAL; slots = __kvm_memslots(kvm, as_id); /* * Note, the old memslot (and the pointer itself!) may be invalidated * and/or destroyed by kvm_set_memslot(). */ old = id_to_memslot(slots, id); if (!mem->memory_size) { if (!old || !old->npages) return -EINVAL; if (WARN_ON_ONCE(kvm->nr_memslot_pages < old->npages)) return -EIO; return kvm_set_memslot(kvm, old, NULL, KVM_MR_DELETE); } base_gfn = (mem->guest_phys_addr >> PAGE_SHIFT); npages = (mem->memory_size >> PAGE_SHIFT); if (!old || !old->npages) { change = KVM_MR_CREATE; /* * To simplify KVM internals, the total number of pages across * all memslots must fit in an unsigned long. */ if ((kvm->nr_memslot_pages + npages) < kvm->nr_memslot_pages) return -EINVAL; } else { /* Modify an existing slot. */ /* Private memslots are immutable, they can only be deleted. */ if (mem->flags & KVM_MEM_GUEST_MEMFD) return -EINVAL; if ((mem->userspace_addr != old->userspace_addr) || (npages != old->npages) || ((mem->flags ^ old->flags) & KVM_MEM_READONLY)) return -EINVAL; if (base_gfn != old->base_gfn) change = KVM_MR_MOVE; else if (mem->flags != old->flags) change = KVM_MR_FLAGS_ONLY; else /* Nothing to change. */ return 0; } if ((change == KVM_MR_CREATE || change == KVM_MR_MOVE) && kvm_check_memslot_overlap(slots, id, base_gfn, base_gfn + npages)) return -EEXIST; /* Allocate a slot that will persist in the memslot. */ new = kzalloc(sizeof(*new), GFP_KERNEL_ACCOUNT); if (!new) return -ENOMEM; new->as_id = as_id; new->id = id; new->base_gfn = base_gfn; new->npages = npages; new->flags = mem->flags; new->userspace_addr = mem->userspace_addr; if (mem->flags & KVM_MEM_GUEST_MEMFD) { r = kvm_gmem_bind(kvm, new, mem->guest_memfd, mem->guest_memfd_offset); if (r) goto out; } r = kvm_set_memslot(kvm, old, new, change); if (r) goto out_unbind; return 0; out_unbind: if (mem->flags & KVM_MEM_GUEST_MEMFD) kvm_gmem_unbind(new); out: kfree(new); return r; } EXPORT_SYMBOL_GPL(__kvm_set_memory_region); int kvm_set_memory_region(struct kvm *kvm, const struct kvm_userspace_memory_region2 *mem) { int r; mutex_lock(&kvm->slots_lock); r = __kvm_set_memory_region(kvm, mem); mutex_unlock(&kvm->slots_lock); return r; } EXPORT_SYMBOL_GPL(kvm_set_memory_region); static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region2 *mem) { if ((u16)mem->slot >= KVM_USER_MEM_SLOTS) return -EINVAL; return kvm_set_memory_region(kvm, mem); } #ifndef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT /** * kvm_get_dirty_log - get a snapshot of dirty pages * @kvm: pointer to kvm instance * @log: slot id and address to which we copy the log * @is_dirty: set to '1' if any dirty pages were found * @memslot: set to the associated memslot, always valid on success */ int kvm_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log, int *is_dirty, struct kvm_memory_slot **memslot) { struct kvm_memslots *slots; int i, as_id, id; unsigned long n; unsigned long any = 0; /* Dirty ring tracking may be exclusive to dirty log tracking */ if (!kvm_use_dirty_bitmap(kvm)) return -ENXIO; *memslot = NULL; *is_dirty = 0; as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS) return -EINVAL; slots = __kvm_memslots(kvm, as_id); *memslot = id_to_memslot(slots, id); if (!(*memslot) || !(*memslot)->dirty_bitmap) return -ENOENT; kvm_arch_sync_dirty_log(kvm, *memslot); n = kvm_dirty_bitmap_bytes(*memslot); for (i = 0; !any && i < n/sizeof(long); ++i) any = (*memslot)->dirty_bitmap[i]; if (copy_to_user(log->dirty_bitmap, (*memslot)->dirty_bitmap, n)) return -EFAULT; if (any) *is_dirty = 1; return 0; } EXPORT_SYMBOL_GPL(kvm_get_dirty_log); #else /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ /** * kvm_get_dirty_log_protect - get a snapshot of dirty pages * and reenable dirty page tracking for the corresponding pages. * @kvm: pointer to kvm instance * @log: slot id and address to which we copy the log * * We need to keep it in mind that VCPU threads can write to the bitmap * concurrently. So, to avoid losing track of dirty pages we keep the * following order: * * 1. Take a snapshot of the bit and clear it if needed. * 2. Write protect the corresponding page. * 3. Copy the snapshot to the userspace. * 4. Upon return caller flushes TLB's if needed. * * Between 2 and 4, the guest may write to the page using the remaining TLB * entry. This is not a problem because the page is reported dirty using * the snapshot taken before and step 4 ensures that writes done after * exiting to userspace will be logged for the next call. * */ static int kvm_get_dirty_log_protect(struct kvm *kvm, struct kvm_dirty_log *log) { struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int i, as_id, id; unsigned long n; unsigned long *dirty_bitmap; unsigned long *dirty_bitmap_buffer; bool flush; /* Dirty ring tracking may be exclusive to dirty log tracking */ if (!kvm_use_dirty_bitmap(kvm)) return -ENXIO; as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS) return -EINVAL; slots = __kvm_memslots(kvm, as_id); memslot = id_to_memslot(slots, id); if (!memslot || !memslot->dirty_bitmap) return -ENOENT; dirty_bitmap = memslot->dirty_bitmap; kvm_arch_sync_dirty_log(kvm, memslot); n = kvm_dirty_bitmap_bytes(memslot); flush = false; if (kvm->manual_dirty_log_protect) { /* * Unlike kvm_get_dirty_log, we always return false in *flush, * because no flush is needed until KVM_CLEAR_DIRTY_LOG. There * is some code duplication between this function and * kvm_get_dirty_log, but hopefully all architecture * transition to kvm_get_dirty_log_protect and kvm_get_dirty_log * can be eliminated. */ dirty_bitmap_buffer = dirty_bitmap; } else { dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot); memset(dirty_bitmap_buffer, 0, n); KVM_MMU_LOCK(kvm); for (i = 0; i < n / sizeof(long); i++) { unsigned long mask; gfn_t offset; if (!dirty_bitmap[i]) continue; flush = true; mask = xchg(&dirty_bitmap[i], 0); dirty_bitmap_buffer[i] = mask; offset = i * BITS_PER_LONG; kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, offset, mask); } KVM_MMU_UNLOCK(kvm); } if (flush) kvm_flush_remote_tlbs_memslot(kvm, memslot); if (copy_to_user(log->dirty_bitmap, dirty_bitmap_buffer, n)) return -EFAULT; return 0; } /** * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot * @kvm: kvm instance * @log: slot id and address to which we copy the log * * Steps 1-4 below provide general overview of dirty page logging. See * kvm_get_dirty_log_protect() function description for additional details. * * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we * always flush the TLB (step 4) even if previous step failed and the dirty * bitmap may be corrupt. Regardless of previous outcome the KVM logging API * does not preclude user space subsequent dirty log read. Flushing TLB ensures * writes will be marked dirty for next log read. * * 1. Take a snapshot of the bit and clear it if needed. * 2. Write protect the corresponding page. * 3. Copy the snapshot to the userspace. * 4. Flush TLB's if needed. */ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log) { int r; mutex_lock(&kvm->slots_lock); r = kvm_get_dirty_log_protect(kvm, log); mutex_unlock(&kvm->slots_lock); return r; } /** * kvm_clear_dirty_log_protect - clear dirty bits in the bitmap * and reenable dirty page tracking for the corresponding pages. * @kvm: pointer to kvm instance * @log: slot id and address from which to fetch the bitmap of dirty pages */ static int kvm_clear_dirty_log_protect(struct kvm *kvm, struct kvm_clear_dirty_log *log) { struct kvm_memslots *slots; struct kvm_memory_slot *memslot; int as_id, id; gfn_t offset; unsigned long i, n; unsigned long *dirty_bitmap; unsigned long *dirty_bitmap_buffer; bool flush; /* Dirty ring tracking may be exclusive to dirty log tracking */ if (!kvm_use_dirty_bitmap(kvm)) return -ENXIO; as_id = log->slot >> 16; id = (u16)log->slot; if (as_id >= kvm_arch_nr_memslot_as_ids(kvm) || id >= KVM_USER_MEM_SLOTS) return -EINVAL; if (log->first_page & 63) return -EINVAL; slots = __kvm_memslots(kvm, as_id); memslot = id_to_memslot(slots, id); if (!memslot || !memslot->dirty_bitmap) return -ENOENT; dirty_bitmap = memslot->dirty_bitmap; n = ALIGN(log->num_pages, BITS_PER_LONG) / 8; if (log->first_page > memslot->npages || log->num_pages > memslot->npages - log->first_page || (log->num_pages < memslot->npages - log->first_page && (log->num_pages & 63))) return -EINVAL; kvm_arch_sync_dirty_log(kvm, memslot); flush = false; dirty_bitmap_buffer = kvm_second_dirty_bitmap(memslot); if (copy_from_user(dirty_bitmap_buffer, log->dirty_bitmap, n)) return -EFAULT; KVM_MMU_LOCK(kvm); for (offset = log->first_page, i = offset / BITS_PER_LONG, n = DIV_ROUND_UP(log->num_pages, BITS_PER_LONG); n--; i++, offset += BITS_PER_LONG) { unsigned long mask = *dirty_bitmap_buffer++; atomic_long_t *p = (atomic_long_t *) &dirty_bitmap[i]; if (!mask) continue; mask &= atomic_long_fetch_andnot(mask, p); /* * mask contains the bits that really have been cleared. This * never includes any bits beyond the length of the memslot (if * the length is not aligned to 64 pages), therefore it is not * a problem if userspace sets them in log->dirty_bitmap. */ if (mask) { flush = true; kvm_arch_mmu_enable_log_dirty_pt_masked(kvm, memslot, offset, mask); } } KVM_MMU_UNLOCK(kvm); if (flush) kvm_flush_remote_tlbs_memslot(kvm, memslot); return 0; } static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm, struct kvm_clear_dirty_log *log) { int r; mutex_lock(&kvm->slots_lock); r = kvm_clear_dirty_log_protect(kvm, log); mutex_unlock(&kvm->slots_lock); return r; } #endif /* CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT */ #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES static u64 kvm_supported_mem_attributes(struct kvm *kvm) { if (!kvm || kvm_arch_has_private_mem(kvm)) return KVM_MEMORY_ATTRIBUTE_PRIVATE; return 0; } /* * Returns true if _all_ gfns in the range [@start, @end) have attributes * such that the bits in @mask match @attrs. */ bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, unsigned long mask, unsigned long attrs) { XA_STATE(xas, &kvm->mem_attr_array, start); unsigned long index; void *entry; mask &= kvm_supported_mem_attributes(kvm); if (attrs & ~mask) return false; if (end == start + 1) return (kvm_get_memory_attributes(kvm, start) & mask) == attrs; guard(rcu)(); if (!attrs) return !xas_find(&xas, end - 1); for (index = start; index < end; index++) { do { entry = xas_next(&xas); } while (xas_retry(&xas, entry)); if (xas.xa_index != index || (xa_to_value(entry) & mask) != attrs) return false; } return true; } static __always_inline void kvm_handle_gfn_range(struct kvm *kvm, struct kvm_mmu_notifier_range *range) { struct kvm_gfn_range gfn_range; struct kvm_memory_slot *slot; struct kvm_memslots *slots; struct kvm_memslot_iter iter; bool found_memslot = false; bool ret = false; int i; gfn_range.arg = range->arg; gfn_range.may_block = range->may_block; for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { slots = __kvm_memslots(kvm, i); kvm_for_each_memslot_in_gfn_range(&iter, slots, range->start, range->end) { slot = iter.slot; gfn_range.slot = slot; gfn_range.start = max(range->start, slot->base_gfn); gfn_range.end = min(range->end, slot->base_gfn + slot->npages); if (gfn_range.start >= gfn_range.end) continue; if (!found_memslot) { found_memslot = true; KVM_MMU_LOCK(kvm); if (!IS_KVM_NULL_FN(range->on_lock)) range->on_lock(kvm); } ret |= range->handler(kvm, &gfn_range); } } if (range->flush_on_ret && ret) kvm_flush_remote_tlbs(kvm); if (found_memslot) KVM_MMU_UNLOCK(kvm); } static bool kvm_pre_set_memory_attributes(struct kvm *kvm, struct kvm_gfn_range *range) { /* * Unconditionally add the range to the invalidation set, regardless of * whether or not the arch callback actually needs to zap SPTEs. E.g. * if KVM supports RWX attributes in the future and the attributes are * going from R=>RW, zapping isn't strictly necessary. Unconditionally * adding the range allows KVM to require that MMU invalidations add at * least one range between begin() and end(), e.g. allows KVM to detect * bugs where the add() is missed. Relaxing the rule *might* be safe, * but it's not obvious that allowing new mappings while the attributes * are in flux is desirable or worth the complexity. */ kvm_mmu_invalidate_range_add(kvm, range->start, range->end); return kvm_arch_pre_set_memory_attributes(kvm, range); } /* Set @attributes for the gfn range [@start, @end). */ static int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, unsigned long attributes) { struct kvm_mmu_notifier_range pre_set_range = { .start = start, .end = end, .handler = kvm_pre_set_memory_attributes, .on_lock = kvm_mmu_invalidate_begin, .flush_on_ret = true, .may_block = true, }; struct kvm_mmu_notifier_range post_set_range = { .start = start, .end = end, .arg.attributes = attributes, .handler = kvm_arch_post_set_memory_attributes, .on_lock = kvm_mmu_invalidate_end, .may_block = true, }; unsigned long i; void *entry; int r = 0; entry = attributes ? xa_mk_value(attributes) : NULL; mutex_lock(&kvm->slots_lock); /* Nothing to do if the entire range as the desired attributes. */ if (kvm_range_has_memory_attributes(kvm, start, end, ~0, attributes)) goto out_unlock; /* * Reserve memory ahead of time to avoid having to deal with failures * partway through setting the new attributes. */ for (i = start; i < end; i++) { r = xa_reserve(&kvm->mem_attr_array, i, GFP_KERNEL_ACCOUNT); if (r) goto out_unlock; } kvm_handle_gfn_range(kvm, &pre_set_range); for (i = start; i < end; i++) { r = xa_err(xa_store(&kvm->mem_attr_array, i, entry, GFP_KERNEL_ACCOUNT)); KVM_BUG_ON(r, kvm); } kvm_handle_gfn_range(kvm, &post_set_range); out_unlock: mutex_unlock(&kvm->slots_lock); return r; } static int kvm_vm_ioctl_set_mem_attributes(struct kvm *kvm, struct kvm_memory_attributes *attrs) { gfn_t start, end; /* flags is currently not used. */ if (attrs->flags) return -EINVAL; if (attrs->attributes & ~kvm_supported_mem_attributes(kvm)) return -EINVAL; if (attrs->size == 0 || attrs->address + attrs->size < attrs->address) return -EINVAL; if (!PAGE_ALIGNED(attrs->address) || !PAGE_ALIGNED(attrs->size)) return -EINVAL; start = attrs->address >> PAGE_SHIFT; end = (attrs->address + attrs->size) >> PAGE_SHIFT; /* * xarray tracks data using "unsigned long", and as a result so does * KVM. For simplicity, supports generic attributes only on 64-bit * architectures. */ BUILD_BUG_ON(sizeof(attrs->attributes) != sizeof(unsigned long)); return kvm_vm_set_mem_attributes(kvm, start, end, attrs->attributes); } #endif /* CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES */ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) { return __gfn_to_memslot(kvm_memslots(kvm), gfn); } EXPORT_SYMBOL_GPL(gfn_to_memslot); struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn) { struct kvm_memslots *slots = kvm_vcpu_memslots(vcpu); u64 gen = slots->generation; struct kvm_memory_slot *slot; /* * This also protects against using a memslot from a different address space, * since different address spaces have different generation numbers. */ if (unlikely(gen != vcpu->last_used_slot_gen)) { vcpu->last_used_slot = NULL; vcpu->last_used_slot_gen = gen; } slot = try_get_memslot(vcpu->last_used_slot, gfn); if (slot) return slot; /* * Fall back to searching all memslots. We purposely use * search_memslots() instead of __gfn_to_memslot() to avoid * thrashing the VM-wide last_used_slot in kvm_memslots. */ slot = search_memslots(slots, gfn, false); if (slot) { vcpu->last_used_slot = slot; return slot; } return NULL; } bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *memslot = gfn_to_memslot(kvm, gfn); return kvm_is_visible_memslot(memslot); } EXPORT_SYMBOL_GPL(kvm_is_visible_gfn); bool kvm_vcpu_is_visible_gfn(struct kvm_vcpu *vcpu, gfn_t gfn) { struct kvm_memory_slot *memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); return kvm_is_visible_memslot(memslot); } EXPORT_SYMBOL_GPL(kvm_vcpu_is_visible_gfn); unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn) { struct vm_area_struct *vma; unsigned long addr, size; size = PAGE_SIZE; addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gfn, NULL); if (kvm_is_error_hva(addr)) return PAGE_SIZE; mmap_read_lock(current->mm); vma = find_vma(current->mm, addr); if (!vma) goto out; size = vma_kernel_pagesize(vma); out: mmap_read_unlock(current->mm); return size; } static bool memslot_is_readonly(const struct kvm_memory_slot *slot) { return slot->flags & KVM_MEM_READONLY; } static unsigned long __gfn_to_hva_many(const struct kvm_memory_slot *slot, gfn_t gfn, gfn_t *nr_pages, bool write) { if (!slot || slot->flags & KVM_MEMSLOT_INVALID) return KVM_HVA_ERR_BAD; if (memslot_is_readonly(slot) && write) return KVM_HVA_ERR_RO_BAD; if (nr_pages) *nr_pages = slot->npages - (gfn - slot->base_gfn); return __gfn_to_hva_memslot(slot, gfn); } static unsigned long gfn_to_hva_many(struct kvm_memory_slot *slot, gfn_t gfn, gfn_t *nr_pages) { return __gfn_to_hva_many(slot, gfn, nr_pages, true); } unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot, gfn_t gfn) { return gfn_to_hva_many(slot, gfn, NULL); } EXPORT_SYMBOL_GPL(gfn_to_hva_memslot); unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) { return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL); } EXPORT_SYMBOL_GPL(gfn_to_hva); unsigned long kvm_vcpu_gfn_to_hva(struct kvm_vcpu *vcpu, gfn_t gfn) { return gfn_to_hva_many(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn, NULL); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_hva); /* * Return the hva of a @gfn and the R/W attribute if possible. * * @slot: the kvm_memory_slot which contains @gfn * @gfn: the gfn to be translated * @writable: used to return the read/write attribute of the @slot if the hva * is valid and @writable is not NULL */ unsigned long gfn_to_hva_memslot_prot(struct kvm_memory_slot *slot, gfn_t gfn, bool *writable) { unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false); if (!kvm_is_error_hva(hva) && writable) *writable = !memslot_is_readonly(slot); return hva; } unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); return gfn_to_hva_memslot_prot(slot, gfn, writable); } unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *writable) { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); return gfn_to_hva_memslot_prot(slot, gfn, writable); } static inline int check_user_page_hwpoison(unsigned long addr) { int rc, flags = FOLL_HWPOISON | FOLL_WRITE; rc = get_user_pages(addr, 1, flags, NULL); return rc == -EHWPOISON; } /* * The fast path to get the writable pfn which will be stored in @pfn, * true indicates success, otherwise false is returned. It's also the * only part that runs if we can in atomic context. */ static bool hva_to_pfn_fast(unsigned long addr, bool write_fault, bool *writable, kvm_pfn_t *pfn) { struct page *page[1]; /* * Fast pin a writable pfn only if it is a write fault request * or the caller allows to map a writable pfn for a read fault * request. */ if (!(write_fault || writable)) return false; if (get_user_page_fast_only(addr, FOLL_WRITE, page)) { *pfn = page_to_pfn(page[0]); if (writable) *writable = true; return true; } return false; } /* * The slow path to get the pfn of the specified host virtual address, * 1 indicates success, -errno is returned if error is detected. */ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault, bool interruptible, bool *writable, kvm_pfn_t *pfn) { /* * When a VCPU accesses a page that is not mapped into the secondary * MMU, we lookup the page using GUP to map it, so the guest VCPU can * make progress. We always want to honor NUMA hinting faults in that * case, because GUP usage corresponds to memory accesses from the VCPU. * Otherwise, we'd not trigger NUMA hinting faults once a page is * mapped into the secondary MMU and gets accessed by a VCPU. * * Note that get_user_page_fast_only() and FOLL_WRITE for now * implicitly honor NUMA hinting faults and don't need this flag. */ unsigned int flags = FOLL_HWPOISON | FOLL_HONOR_NUMA_FAULT; struct page *page; int npages; might_sleep(); if (writable) *writable = write_fault; if (write_fault) flags |= FOLL_WRITE; if (async) flags |= FOLL_NOWAIT; if (interruptible) flags |= FOLL_INTERRUPTIBLE; npages = get_user_pages_unlocked(addr, 1, &page, flags); if (npages != 1) return npages; /* map read fault as writable if possible */ if (unlikely(!write_fault) && writable) { struct page *wpage; if (get_user_page_fast_only(addr, FOLL_WRITE, &wpage)) { *writable = true; put_page(page); page = wpage; } } *pfn = page_to_pfn(page); return npages; } static bool vma_is_valid(struct vm_area_struct *vma, bool write_fault) { if (unlikely(!(vma->vm_flags & VM_READ))) return false; if (write_fault && (unlikely(!(vma->vm_flags & VM_WRITE)))) return false; return true; } static int kvm_try_get_pfn(kvm_pfn_t pfn) { struct page *page = kvm_pfn_to_refcounted_page(pfn); if (!page) return 1; return get_page_unless_zero(page); } static int hva_to_pfn_remapped(struct vm_area_struct *vma, unsigned long addr, bool write_fault, bool *writable, kvm_pfn_t *p_pfn) { kvm_pfn_t pfn; pte_t *ptep; pte_t pte; spinlock_t *ptl; int r; r = follow_pte(vma, addr, &ptep, &ptl); if (r) { /* * get_user_pages fails for VM_IO and VM_PFNMAP vmas and does * not call the fault handler, so do it here. */ bool unlocked = false; r = fixup_user_fault(current->mm, addr, (write_fault ? FAULT_FLAG_WRITE : 0), &unlocked); if (unlocked) return -EAGAIN; if (r) return r; r = follow_pte(vma, addr, &ptep, &ptl); if (r) return r; } pte = ptep_get(ptep); if (write_fault && !pte_write(pte)) { pfn = KVM_PFN_ERR_RO_FAULT; goto out; } if (writable) *writable = pte_write(pte); pfn = pte_pfn(pte); /* * Get a reference here because callers of *hva_to_pfn* and * *gfn_to_pfn* ultimately call kvm_release_pfn_clean on the * returned pfn. This is only needed if the VMA has VM_MIXEDMAP * set, but the kvm_try_get_pfn/kvm_release_pfn_clean pair will * simply do nothing for reserved pfns. * * Whoever called remap_pfn_range is also going to call e.g. * unmap_mapping_range before the underlying pages are freed, * causing a call to our MMU notifier. * * Certain IO or PFNMAP mappings can be backed with valid * struct pages, but be allocated without refcounting e.g., * tail pages of non-compound higher order allocations, which * would then underflow the refcount when the caller does the * required put_page. Don't allow those pages here. */ if (!kvm_try_get_pfn(pfn)) r = -EFAULT; out: pte_unmap_unlock(ptep, ptl); *p_pfn = pfn; return r; } /* * Pin guest page in memory and return its pfn. * @addr: host virtual address which maps memory to the guest * @atomic: whether this function is forbidden from sleeping * @interruptible: whether the process can be interrupted by non-fatal signals * @async: whether this function need to wait IO complete if the * host page is not in the memory * @write_fault: whether we should get a writable host page * @writable: whether it allows to map a writable host page for !@write_fault * * The function will map a writable host page for these two cases: * 1): @write_fault = true * 2): @write_fault = false && @writable, @writable will tell the caller * whether the mapping is writable. */ kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool interruptible, bool *async, bool write_fault, bool *writable) { struct vm_area_struct *vma; kvm_pfn_t pfn; int npages, r; /* we can do it either atomically or asynchronously, not both */ BUG_ON(atomic && async); if (hva_to_pfn_fast(addr, write_fault, writable, &pfn)) return pfn; if (atomic) return KVM_PFN_ERR_FAULT; npages = hva_to_pfn_slow(addr, async, write_fault, interruptible, writable, &pfn); if (npages == 1) return pfn; if (npages == -EINTR) return KVM_PFN_ERR_SIGPENDING; mmap_read_lock(current->mm); if (npages == -EHWPOISON || (!async && check_user_page_hwpoison(addr))) { pfn = KVM_PFN_ERR_HWPOISON; goto exit; } retry: vma = vma_lookup(current->mm, addr); if (vma == NULL) pfn = KVM_PFN_ERR_FAULT; else if (vma->vm_flags & (VM_IO | VM_PFNMAP)) { r = hva_to_pfn_remapped(vma, addr, write_fault, writable, &pfn); if (r == -EAGAIN) goto retry; if (r < 0) pfn = KVM_PFN_ERR_FAULT; } else { if (async && vma_is_valid(vma, write_fault)) *async = true; pfn = KVM_PFN_ERR_FAULT; } exit: mmap_read_unlock(current->mm); return pfn; } kvm_pfn_t __gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn, bool atomic, bool interruptible, bool *async, bool write_fault, bool *writable, hva_t *hva) { unsigned long addr = __gfn_to_hva_many(slot, gfn, NULL, write_fault); if (hva) *hva = addr; if (kvm_is_error_hva(addr)) { if (writable) *writable = false; return addr == KVM_HVA_ERR_RO_BAD ? KVM_PFN_ERR_RO_FAULT : KVM_PFN_NOSLOT; } /* Do not map writable pfn in the readonly memslot. */ if (writable && memslot_is_readonly(slot)) { *writable = false; writable = NULL; } return hva_to_pfn(addr, atomic, interruptible, async, write_fault, writable); } EXPORT_SYMBOL_GPL(__gfn_to_pfn_memslot); kvm_pfn_t gfn_to_pfn_prot(struct kvm *kvm, gfn_t gfn, bool write_fault, bool *writable) { return __gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn, false, false, NULL, write_fault, writable, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_prot); kvm_pfn_t gfn_to_pfn_memslot(const struct kvm_memory_slot *slot, gfn_t gfn) { return __gfn_to_pfn_memslot(slot, gfn, false, false, NULL, true, NULL, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot); kvm_pfn_t gfn_to_pfn_memslot_atomic(const struct kvm_memory_slot *slot, gfn_t gfn) { return __gfn_to_pfn_memslot(slot, gfn, true, false, NULL, true, NULL, NULL); } EXPORT_SYMBOL_GPL(gfn_to_pfn_memslot_atomic); kvm_pfn_t kvm_vcpu_gfn_to_pfn_atomic(struct kvm_vcpu *vcpu, gfn_t gfn) { return gfn_to_pfn_memslot_atomic(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn_atomic); kvm_pfn_t gfn_to_pfn(struct kvm *kvm, gfn_t gfn) { return gfn_to_pfn_memslot(gfn_to_memslot(kvm, gfn), gfn); } EXPORT_SYMBOL_GPL(gfn_to_pfn); kvm_pfn_t kvm_vcpu_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn) { return gfn_to_pfn_memslot(kvm_vcpu_gfn_to_memslot(vcpu, gfn), gfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_pfn); int gfn_to_page_many_atomic(struct kvm_memory_slot *slot, gfn_t gfn, struct page **pages, int nr_pages) { unsigned long addr; gfn_t entry = 0; addr = gfn_to_hva_many(slot, gfn, &entry); if (kvm_is_error_hva(addr)) return -1; if (entry < nr_pages) return 0; return get_user_pages_fast_only(addr, nr_pages, FOLL_WRITE, pages); } EXPORT_SYMBOL_GPL(gfn_to_page_many_atomic); /* * Do not use this helper unless you are absolutely certain the gfn _must_ be * backed by 'struct page'. A valid example is if the backing memslot is * controlled by KVM. Note, if the returned page is valid, it's refcount has * been elevated by gfn_to_pfn(). */ struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) { struct page *page; kvm_pfn_t pfn; pfn = gfn_to_pfn(kvm, gfn); if (is_error_noslot_pfn(pfn)) return KVM_ERR_PTR_BAD_PAGE; page = kvm_pfn_to_refcounted_page(pfn); if (!page) return KVM_ERR_PTR_BAD_PAGE; return page; } EXPORT_SYMBOL_GPL(gfn_to_page); void kvm_release_pfn(kvm_pfn_t pfn, bool dirty) { if (dirty) kvm_release_pfn_dirty(pfn); else kvm_release_pfn_clean(pfn); } int kvm_vcpu_map(struct kvm_vcpu *vcpu, gfn_t gfn, struct kvm_host_map *map) { kvm_pfn_t pfn; void *hva = NULL; struct page *page = KVM_UNMAPPED_PAGE; if (!map) return -EINVAL; pfn = gfn_to_pfn(vcpu->kvm, gfn); if (is_error_noslot_pfn(pfn)) return -EINVAL; if (pfn_valid(pfn)) { page = pfn_to_page(pfn); hva = kmap(page); #ifdef CONFIG_HAS_IOMEM } else { hva = memremap(pfn_to_hpa(pfn), PAGE_SIZE, MEMREMAP_WB); #endif } if (!hva) return -EFAULT; map->page = page; map->hva = hva; map->pfn = pfn; map->gfn = gfn; return 0; } EXPORT_SYMBOL_GPL(kvm_vcpu_map); void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map, bool dirty) { if (!map) return; if (!map->hva) return; if (map->page != KVM_UNMAPPED_PAGE) kunmap(map->page); #ifdef CONFIG_HAS_IOMEM else memunmap(map->hva); #endif if (dirty) kvm_vcpu_mark_page_dirty(vcpu, map->gfn); kvm_release_pfn(map->pfn, dirty); map->hva = NULL; map->page = NULL; } EXPORT_SYMBOL_GPL(kvm_vcpu_unmap); static bool kvm_is_ad_tracked_page(struct page *page) { /* * Per page-flags.h, pages tagged PG_reserved "should in general not be * touched (e.g. set dirty) except by its owner". */ return !PageReserved(page); } static void kvm_set_page_dirty(struct page *page) { if (kvm_is_ad_tracked_page(page)) SetPageDirty(page); } static void kvm_set_page_accessed(struct page *page) { if (kvm_is_ad_tracked_page(page)) mark_page_accessed(page); } void kvm_release_page_clean(struct page *page) { WARN_ON(is_error_page(page)); kvm_set_page_accessed(page); put_page(page); } EXPORT_SYMBOL_GPL(kvm_release_page_clean); void kvm_release_pfn_clean(kvm_pfn_t pfn) { struct page *page; if (is_error_noslot_pfn(pfn)) return; page = kvm_pfn_to_refcounted_page(pfn); if (!page) return; kvm_release_page_clean(page); } EXPORT_SYMBOL_GPL(kvm_release_pfn_clean); void kvm_release_page_dirty(struct page *page) { WARN_ON(is_error_page(page)); kvm_set_page_dirty(page); kvm_release_page_clean(page); } EXPORT_SYMBOL_GPL(kvm_release_page_dirty); void kvm_release_pfn_dirty(kvm_pfn_t pfn) { struct page *page; if (is_error_noslot_pfn(pfn)) return; page = kvm_pfn_to_refcounted_page(pfn); if (!page) return; kvm_release_page_dirty(page); } EXPORT_SYMBOL_GPL(kvm_release_pfn_dirty); /* * Note, checking for an error/noslot pfn is the caller's responsibility when * directly marking a page dirty/accessed. Unlike the "release" helpers, the * "set" helpers are not to be used when the pfn might point at garbage. */ void kvm_set_pfn_dirty(kvm_pfn_t pfn) { if (WARN_ON(is_error_noslot_pfn(pfn))) return; if (pfn_valid(pfn)) kvm_set_page_dirty(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_set_pfn_dirty); void kvm_set_pfn_accessed(kvm_pfn_t pfn) { if (WARN_ON(is_error_noslot_pfn(pfn))) return; if (pfn_valid(pfn)) kvm_set_page_accessed(pfn_to_page(pfn)); } EXPORT_SYMBOL_GPL(kvm_set_pfn_accessed); static int next_segment(unsigned long len, int offset) { if (len > PAGE_SIZE - offset) return PAGE_SIZE - offset; else return len; } /* Copy @len bytes from guest memory at '(@gfn * PAGE_SIZE) + @offset' to @data */ static int __kvm_read_guest_page(struct kvm_memory_slot *slot, gfn_t gfn, void *data, int offset, int len) { int r; unsigned long addr; addr = gfn_to_hva_memslot_prot(slot, gfn, NULL); if (kvm_is_error_hva(addr)) return -EFAULT; r = __copy_from_user(data, (void __user *)addr + offset, len); if (r) return -EFAULT; return 0; } int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, int len) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); return __kvm_read_guest_page(slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_read_guest_page); int kvm_vcpu_read_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, void *data, int offset, int len) { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); return __kvm_read_guest_page(slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_page); int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; int seg; int offset = offset_in_page(gpa); int ret; while ((seg = next_segment(len, offset)) != 0) { ret = kvm_read_guest_page(kvm, gfn, data, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; data += seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_read_guest); int kvm_vcpu_read_guest(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; int seg; int offset = offset_in_page(gpa); int ret; while ((seg = next_segment(len, offset)) != 0) { ret = kvm_vcpu_read_guest_page(vcpu, gfn, data, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; data += seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest); static int __kvm_read_guest_atomic(struct kvm_memory_slot *slot, gfn_t gfn, void *data, int offset, unsigned long len) { int r; unsigned long addr; addr = gfn_to_hva_memslot_prot(slot, gfn, NULL); if (kvm_is_error_hva(addr)) return -EFAULT; pagefault_disable(); r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len); pagefault_enable(); if (r) return -EFAULT; return 0; } int kvm_vcpu_read_guest_atomic(struct kvm_vcpu *vcpu, gpa_t gpa, void *data, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); int offset = offset_in_page(gpa); return __kvm_read_guest_atomic(slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_vcpu_read_guest_atomic); /* Copy @len bytes from @data into guest memory at '(@gfn * PAGE_SIZE) + @offset' */ static int __kvm_write_guest_page(struct kvm *kvm, struct kvm_memory_slot *memslot, gfn_t gfn, const void *data, int offset, int len) { int r; unsigned long addr; addr = gfn_to_hva_memslot(memslot, gfn); if (kvm_is_error_hva(addr)) return -EFAULT; r = __copy_to_user((void __user *)addr + offset, data, len); if (r) return -EFAULT; mark_page_dirty_in_slot(kvm, memslot, gfn); return 0; } int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, int offset, int len) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); return __kvm_write_guest_page(kvm, slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_write_guest_page); int kvm_vcpu_write_guest_page(struct kvm_vcpu *vcpu, gfn_t gfn, const void *data, int offset, int len) { struct kvm_memory_slot *slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); return __kvm_write_guest_page(vcpu->kvm, slot, gfn, data, offset, len); } EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest_page); int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; int seg; int offset = offset_in_page(gpa); int ret; while ((seg = next_segment(len, offset)) != 0) { ret = kvm_write_guest_page(kvm, gfn, data, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; data += seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_write_guest); int kvm_vcpu_write_guest(struct kvm_vcpu *vcpu, gpa_t gpa, const void *data, unsigned long len) { gfn_t gfn = gpa >> PAGE_SHIFT; int seg; int offset = offset_in_page(gpa); int ret; while ((seg = next_segment(len, offset)) != 0) { ret = kvm_vcpu_write_guest_page(vcpu, gfn, data, offset, seg); if (ret < 0) return ret; offset = 0; len -= seg; data += seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_vcpu_write_guest); static int __kvm_gfn_to_hva_cache_init(struct kvm_memslots *slots, struct gfn_to_hva_cache *ghc, gpa_t gpa, unsigned long len) { int offset = offset_in_page(gpa); gfn_t start_gfn = gpa >> PAGE_SHIFT; gfn_t end_gfn = (gpa + len - 1) >> PAGE_SHIFT; gfn_t nr_pages_needed = end_gfn - start_gfn + 1; gfn_t nr_pages_avail; /* Update ghc->generation before performing any error checks. */ ghc->generation = slots->generation; if (start_gfn > end_gfn) { ghc->hva = KVM_HVA_ERR_BAD; return -EINVAL; } /* * If the requested region crosses two memslots, we still * verify that the entire region is valid here. */ for ( ; start_gfn <= end_gfn; start_gfn += nr_pages_avail) { ghc->memslot = __gfn_to_memslot(slots, start_gfn); ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail); if (kvm_is_error_hva(ghc->hva)) return -EFAULT; } /* Use the slow path for cross page reads and writes. */ if (nr_pages_needed == 1) ghc->hva += offset; else ghc->memslot = NULL; ghc->gpa = gpa; ghc->len = len; return 0; } int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc, gpa_t gpa, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); return __kvm_gfn_to_hva_cache_init(slots, ghc, gpa, len); } EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init); int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned int offset, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int r; gpa_t gpa = ghc->gpa + offset; if (WARN_ON_ONCE(len + offset > ghc->len)) return -EINVAL; if (slots->generation != ghc->generation) { if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) return -EFAULT; } if (kvm_is_error_hva(ghc->hva)) return -EFAULT; if (unlikely(!ghc->memslot)) return kvm_write_guest(kvm, gpa, data, len); r = __copy_to_user((void __user *)ghc->hva + offset, data, len); if (r) return -EFAULT; mark_page_dirty_in_slot(kvm, ghc->memslot, gpa >> PAGE_SHIFT); return 0; } EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached); int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len) { return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len); } EXPORT_SYMBOL_GPL(kvm_write_guest_cached); int kvm_read_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned int offset, unsigned long len) { struct kvm_memslots *slots = kvm_memslots(kvm); int r; gpa_t gpa = ghc->gpa + offset; if (WARN_ON_ONCE(len + offset > ghc->len)) return -EINVAL; if (slots->generation != ghc->generation) { if (__kvm_gfn_to_hva_cache_init(slots, ghc, ghc->gpa, ghc->len)) return -EFAULT; } if (kvm_is_error_hva(ghc->hva)) return -EFAULT; if (unlikely(!ghc->memslot)) return kvm_read_guest(kvm, gpa, data, len); r = __copy_from_user(data, (void __user *)ghc->hva + offset, len); if (r) return -EFAULT; return 0; } EXPORT_SYMBOL_GPL(kvm_read_guest_offset_cached); int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, void *data, unsigned long len) { return kvm_read_guest_offset_cached(kvm, ghc, data, 0, len); } EXPORT_SYMBOL_GPL(kvm_read_guest_cached); int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len) { const void *zero_page = (const void *) __va(page_to_phys(ZERO_PAGE(0))); gfn_t gfn = gpa >> PAGE_SHIFT; int seg; int offset = offset_in_page(gpa); int ret; while ((seg = next_segment(len, offset)) != 0) { ret = kvm_write_guest_page(kvm, gfn, zero_page, offset, len); if (ret < 0) return ret; offset = 0; len -= seg; ++gfn; } return 0; } EXPORT_SYMBOL_GPL(kvm_clear_guest); void mark_page_dirty_in_slot(struct kvm *kvm, const struct kvm_memory_slot *memslot, gfn_t gfn) { struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); #ifdef CONFIG_HAVE_KVM_DIRTY_RING if (WARN_ON_ONCE(vcpu && vcpu->kvm != kvm)) return; WARN_ON_ONCE(!vcpu && !kvm_arch_allow_write_without_running_vcpu(kvm)); #endif if (memslot && kvm_slot_dirty_track_enabled(memslot)) { unsigned long rel_gfn = gfn - memslot->base_gfn; u32 slot = (memslot->as_id << 16) | memslot->id; if (kvm->dirty_ring_size && vcpu) kvm_dirty_ring_push(vcpu, slot, rel_gfn); else if (memslot->dirty_bitmap) set_bit_le(rel_gfn, memslot->dirty_bitmap); } } EXPORT_SYMBOL_GPL(mark_page_dirty_in_slot); void mark_page_dirty(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *memslot; memslot = gfn_to_memslot(kvm, gfn); mark_page_dirty_in_slot(kvm, memslot, gfn); } EXPORT_SYMBOL_GPL(mark_page_dirty); void kvm_vcpu_mark_page_dirty(struct kvm_vcpu *vcpu, gfn_t gfn) { struct kvm_memory_slot *memslot; memslot = kvm_vcpu_gfn_to_memslot(vcpu, gfn); mark_page_dirty_in_slot(vcpu->kvm, memslot, gfn); } EXPORT_SYMBOL_GPL(kvm_vcpu_mark_page_dirty); void kvm_sigset_activate(struct kvm_vcpu *vcpu) { if (!vcpu->sigset_active) return; /* * This does a lockless modification of ->real_blocked, which is fine * because, only current can change ->real_blocked and all readers of * ->real_blocked don't care as long ->real_blocked is always a subset * of ->blocked. */ sigprocmask(SIG_SETMASK, &vcpu->sigset, ¤t->real_blocked); } void kvm_sigset_deactivate(struct kvm_vcpu *vcpu) { if (!vcpu->sigset_active) return; sigprocmask(SIG_SETMASK, ¤t->real_blocked, NULL); sigemptyset(¤t->real_blocked); } static void grow_halt_poll_ns(struct kvm_vcpu *vcpu) { unsigned int old, val, grow, grow_start; old = val = vcpu->halt_poll_ns; grow_start = READ_ONCE(halt_poll_ns_grow_start); grow = READ_ONCE(halt_poll_ns_grow); if (!grow) goto out; val *= grow; if (val < grow_start) val = grow_start; vcpu->halt_poll_ns = val; out: trace_kvm_halt_poll_ns_grow(vcpu->vcpu_id, val, old); } static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu) { unsigned int old, val, shrink, grow_start; old = val = vcpu->halt_poll_ns; shrink = READ_ONCE(halt_poll_ns_shrink); grow_start = READ_ONCE(halt_poll_ns_grow_start); if (shrink == 0) val = 0; else val /= shrink; if (val < grow_start) val = 0; vcpu->halt_poll_ns = val; trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old); } static int kvm_vcpu_check_block(struct kvm_vcpu *vcpu) { int ret = -EINTR; int idx = srcu_read_lock(&vcpu->kvm->srcu); if (kvm_arch_vcpu_runnable(vcpu)) goto out; if (kvm_cpu_has_pending_timer(vcpu)) goto out; if (signal_pending(current)) goto out; if (kvm_check_request(KVM_REQ_UNBLOCK, vcpu)) goto out; ret = 0; out: srcu_read_unlock(&vcpu->kvm->srcu, idx); return ret; } /* * Block the vCPU until the vCPU is runnable, an event arrives, or a signal is * pending. This is mostly used when halting a vCPU, but may also be used * directly for other vCPU non-runnable states, e.g. x86's Wait-For-SIPI. */ bool kvm_vcpu_block(struct kvm_vcpu *vcpu) { struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu); bool waited = false; vcpu->stat.generic.blocking = 1; preempt_disable(); kvm_arch_vcpu_blocking(vcpu); prepare_to_rcuwait(wait); preempt_enable(); for (;;) { set_current_state(TASK_INTERRUPTIBLE); if (kvm_vcpu_check_block(vcpu) < 0) break; waited = true; schedule(); } preempt_disable(); finish_rcuwait(wait); kvm_arch_vcpu_unblocking(vcpu); preempt_enable(); vcpu->stat.generic.blocking = 0; return waited; } static inline void update_halt_poll_stats(struct kvm_vcpu *vcpu, ktime_t start, ktime_t end, bool success) { struct kvm_vcpu_stat_generic *stats = &vcpu->stat.generic; u64 poll_ns = ktime_to_ns(ktime_sub(end, start)); ++vcpu->stat.generic.halt_attempted_poll; if (success) { ++vcpu->stat.generic.halt_successful_poll; if (!vcpu_valid_wakeup(vcpu)) ++vcpu->stat.generic.halt_poll_invalid; stats->halt_poll_success_ns += poll_ns; KVM_STATS_LOG_HIST_UPDATE(stats->halt_poll_success_hist, poll_ns); } else { stats->halt_poll_fail_ns += poll_ns; KVM_STATS_LOG_HIST_UPDATE(stats->halt_poll_fail_hist, poll_ns); } } static unsigned int kvm_vcpu_max_halt_poll_ns(struct kvm_vcpu *vcpu) { struct kvm *kvm = vcpu->kvm; if (kvm->override_halt_poll_ns) { /* * Ensure kvm->max_halt_poll_ns is not read before * kvm->override_halt_poll_ns. * * Pairs with the smp_wmb() when enabling KVM_CAP_HALT_POLL. */ smp_rmb(); return READ_ONCE(kvm->max_halt_poll_ns); } return READ_ONCE(halt_poll_ns); } /* * Emulate a vCPU halt condition, e.g. HLT on x86, WFI on arm, etc... If halt * polling is enabled, busy wait for a short time before blocking to avoid the * expensive block+unblock sequence if a wake event arrives soon after the vCPU * is halted. */ void kvm_vcpu_halt(struct kvm_vcpu *vcpu) { unsigned int max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu); bool halt_poll_allowed = !kvm_arch_no_poll(vcpu); ktime_t start, cur, poll_end; bool waited = false; bool do_halt_poll; u64 halt_ns; if (vcpu->halt_poll_ns > max_halt_poll_ns) vcpu->halt_poll_ns = max_halt_poll_ns; do_halt_poll = halt_poll_allowed && vcpu->halt_poll_ns; start = cur = poll_end = ktime_get(); if (do_halt_poll) { ktime_t stop = ktime_add_ns(start, vcpu->halt_poll_ns); do { if (kvm_vcpu_check_block(vcpu) < 0) goto out; cpu_relax(); poll_end = cur = ktime_get(); } while (kvm_vcpu_can_poll(cur, stop)); } waited = kvm_vcpu_block(vcpu); cur = ktime_get(); if (waited) { vcpu->stat.generic.halt_wait_ns += ktime_to_ns(cur) - ktime_to_ns(poll_end); KVM_STATS_LOG_HIST_UPDATE(vcpu->stat.generic.halt_wait_hist, ktime_to_ns(cur) - ktime_to_ns(poll_end)); } out: /* The total time the vCPU was "halted", including polling time. */ halt_ns = ktime_to_ns(cur) - ktime_to_ns(start); /* * Note, halt-polling is considered successful so long as the vCPU was * never actually scheduled out, i.e. even if the wake event arrived * after of the halt-polling loop itself, but before the full wait. */ if (do_halt_poll) update_halt_poll_stats(vcpu, start, poll_end, !waited); if (halt_poll_allowed) { /* Recompute the max halt poll time in case it changed. */ max_halt_poll_ns = kvm_vcpu_max_halt_poll_ns(vcpu); if (!vcpu_valid_wakeup(vcpu)) { shrink_halt_poll_ns(vcpu); } else if (max_halt_poll_ns) { if (halt_ns <= vcpu->halt_poll_ns) ; /* we had a long block, shrink polling */ else if (vcpu->halt_poll_ns && halt_ns > max_halt_poll_ns) shrink_halt_poll_ns(vcpu); /* we had a short halt and our poll time is too small */ else if (vcpu->halt_poll_ns < max_halt_poll_ns && halt_ns < max_halt_poll_ns) grow_halt_poll_ns(vcpu); } else { vcpu->halt_poll_ns = 0; } } trace_kvm_vcpu_wakeup(halt_ns, waited, vcpu_valid_wakeup(vcpu)); } EXPORT_SYMBOL_GPL(kvm_vcpu_halt); bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu) { if (__kvm_vcpu_wake_up(vcpu)) { WRITE_ONCE(vcpu->ready, true); ++vcpu->stat.generic.halt_wakeup; return true; } return false; } EXPORT_SYMBOL_GPL(kvm_vcpu_wake_up); #ifndef CONFIG_S390 /* * Kick a sleeping VCPU, or a guest VCPU in guest mode, into host kernel mode. */ void kvm_vcpu_kick(struct kvm_vcpu *vcpu) { int me, cpu; if (kvm_vcpu_wake_up(vcpu)) return; me = get_cpu(); /* * The only state change done outside the vcpu mutex is IN_GUEST_MODE * to EXITING_GUEST_MODE. Therefore the moderately expensive "should * kick" check does not need atomic operations if kvm_vcpu_kick is used * within the vCPU thread itself. */ if (vcpu == __this_cpu_read(kvm_running_vcpu)) { if (vcpu->mode == IN_GUEST_MODE) WRITE_ONCE(vcpu->mode, EXITING_GUEST_MODE); goto out; } /* * Note, the vCPU could get migrated to a different pCPU at any point * after kvm_arch_vcpu_should_kick(), which could result in sending an * IPI to the previous pCPU. But, that's ok because the purpose of the * IPI is to force the vCPU to leave IN_GUEST_MODE, and migrating the * vCPU also requires it to leave IN_GUEST_MODE. */ if (kvm_arch_vcpu_should_kick(vcpu)) { cpu = READ_ONCE(vcpu->cpu); if (cpu != me && (unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) smp_send_reschedule(cpu); } out: put_cpu(); } EXPORT_SYMBOL_GPL(kvm_vcpu_kick); #endif /* !CONFIG_S390 */ int kvm_vcpu_yield_to(struct kvm_vcpu *target) { struct pid *pid; struct task_struct *task = NULL; int ret = 0; rcu_read_lock(); pid = rcu_dereference(target->pid); if (pid) task = get_pid_task(pid, PIDTYPE_PID); rcu_read_unlock(); if (!task) return ret; ret = yield_to(task, 1); put_task_struct(task); return ret; } EXPORT_SYMBOL_GPL(kvm_vcpu_yield_to); /* * Helper that checks whether a VCPU is eligible for directed yield. * Most eligible candidate to yield is decided by following heuristics: * * (a) VCPU which has not done pl-exit or cpu relax intercepted recently * (preempted lock holder), indicated by @in_spin_loop. * Set at the beginning and cleared at the end of interception/PLE handler. * * (b) VCPU which has done pl-exit/ cpu relax intercepted but did not get * chance last time (mostly it has become eligible now since we have probably * yielded to lockholder in last iteration. This is done by toggling * @dy_eligible each time a VCPU checked for eligibility.) * * Yielding to a recently pl-exited/cpu relax intercepted VCPU before yielding * to preempted lock-holder could result in wrong VCPU selection and CPU * burning. Giving priority for a potential lock-holder increases lock * progress. * * Since algorithm is based on heuristics, accessing another VCPU data without * locking does not harm. It may result in trying to yield to same VCPU, fail * and continue with next VCPU and so on. */ static bool kvm_vcpu_eligible_for_directed_yield(struct kvm_vcpu *vcpu) { #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT bool eligible; eligible = !vcpu->spin_loop.in_spin_loop || vcpu->spin_loop.dy_eligible; if (vcpu->spin_loop.in_spin_loop) kvm_vcpu_set_dy_eligible(vcpu, !vcpu->spin_loop.dy_eligible); return eligible; #else return true; #endif } /* * Unlike kvm_arch_vcpu_runnable, this function is called outside * a vcpu_load/vcpu_put pair. However, for most architectures * kvm_arch_vcpu_runnable does not require vcpu_load. */ bool __weak kvm_arch_dy_runnable(struct kvm_vcpu *vcpu) { return kvm_arch_vcpu_runnable(vcpu); } static bool vcpu_dy_runnable(struct kvm_vcpu *vcpu) { if (kvm_arch_dy_runnable(vcpu)) return true; #ifdef CONFIG_KVM_ASYNC_PF if (!list_empty_careful(&vcpu->async_pf.done)) return true; #endif return false; } /* * By default, simply query the target vCPU's current mode when checking if a * vCPU was preempted in kernel mode. All architectures except x86 (or more * specifical, except VMX) allow querying whether or not a vCPU is in kernel * mode even if the vCPU is NOT loaded, i.e. using kvm_arch_vcpu_in_kernel() * directly for cross-vCPU checks is functionally correct and accurate. */ bool __weak kvm_arch_vcpu_preempted_in_kernel(struct kvm_vcpu *vcpu) { return kvm_arch_vcpu_in_kernel(vcpu); } bool __weak kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu) { return false; } void kvm_vcpu_on_spin(struct kvm_vcpu *me, bool yield_to_kernel_mode) { struct kvm *kvm = me->kvm; struct kvm_vcpu *vcpu; int last_boosted_vcpu; unsigned long i; int yielded = 0; int try = 3; int pass; last_boosted_vcpu = READ_ONCE(kvm->last_boosted_vcpu); kvm_vcpu_set_in_spin_loop(me, true); /* * We boost the priority of a VCPU that is runnable but not * currently running, because it got preempted by something * else and called schedule in __vcpu_run. Hopefully that * VCPU is holding the lock that we need and will release it. * We approximate round-robin by starting at the last boosted VCPU. */ for (pass = 0; pass < 2 && !yielded && try; pass++) { kvm_for_each_vcpu(i, vcpu, kvm) { if (!pass && i <= last_boosted_vcpu) { i = last_boosted_vcpu; continue; } else if (pass && i > last_boosted_vcpu) break; if (!READ_ONCE(vcpu->ready)) continue; if (vcpu == me) continue; if (kvm_vcpu_is_blocking(vcpu) && !vcpu_dy_runnable(vcpu)) continue; /* * Treat the target vCPU as being in-kernel if it has a * pending interrupt, as the vCPU trying to yield may * be spinning waiting on IPI delivery, i.e. the target * vCPU is in-kernel for the purposes of directed yield. */ if (READ_ONCE(vcpu->preempted) && yield_to_kernel_mode && !kvm_arch_dy_has_pending_interrupt(vcpu) && !kvm_arch_vcpu_preempted_in_kernel(vcpu)) continue; if (!kvm_vcpu_eligible_for_directed_yield(vcpu)) continue; yielded = kvm_vcpu_yield_to(vcpu); if (yielded > 0) { WRITE_ONCE(kvm->last_boosted_vcpu, i); break; } else if (yielded < 0) { try--; if (!try) break; } } } kvm_vcpu_set_in_spin_loop(me, false); /* Ensure vcpu is not eligible during next spinloop */ kvm_vcpu_set_dy_eligible(me, false); } EXPORT_SYMBOL_GPL(kvm_vcpu_on_spin); static bool kvm_page_in_dirty_ring(struct kvm *kvm, unsigned long pgoff) { #ifdef CONFIG_HAVE_KVM_DIRTY_RING return (pgoff >= KVM_DIRTY_LOG_PAGE_OFFSET) && (pgoff < KVM_DIRTY_LOG_PAGE_OFFSET + kvm->dirty_ring_size / PAGE_SIZE); #else return false; #endif } static vm_fault_t kvm_vcpu_fault(struct vm_fault *vmf) { struct kvm_vcpu *vcpu = vmf->vma->vm_file->private_data; struct page *page; if (vmf->pgoff == 0) page = virt_to_page(vcpu->run); #ifdef CONFIG_X86 else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET) page = virt_to_page(vcpu->arch.pio_data); #endif #ifdef CONFIG_KVM_MMIO else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET) page = virt_to_page(vcpu->kvm->coalesced_mmio_ring); #endif else if (kvm_page_in_dirty_ring(vcpu->kvm, vmf->pgoff)) page = kvm_dirty_ring_get_page( &vcpu->dirty_ring, vmf->pgoff - KVM_DIRTY_LOG_PAGE_OFFSET); else return kvm_arch_vcpu_fault(vcpu, vmf); get_page(page); vmf->page = page; return 0; } static const struct vm_operations_struct kvm_vcpu_vm_ops = { .fault = kvm_vcpu_fault, }; static int kvm_vcpu_mmap(struct file *file, struct vm_area_struct *vma) { struct kvm_vcpu *vcpu = file->private_data; unsigned long pages = vma_pages(vma); if ((kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff) || kvm_page_in_dirty_ring(vcpu->kvm, vma->vm_pgoff + pages - 1)) && ((vma->vm_flags & VM_EXEC) || !(vma->vm_flags & VM_SHARED))) return -EINVAL; vma->vm_ops = &kvm_vcpu_vm_ops; return 0; } static int kvm_vcpu_release(struct inode *inode, struct file *filp) { struct kvm_vcpu *vcpu = filp->private_data; kvm_put_kvm(vcpu->kvm); return 0; } static struct file_operations kvm_vcpu_fops = { .release = kvm_vcpu_release, .unlocked_ioctl = kvm_vcpu_ioctl, .mmap = kvm_vcpu_mmap, .llseek = noop_llseek, KVM_COMPAT(kvm_vcpu_compat_ioctl), }; /* * Allocates an inode for the vcpu. */ static int create_vcpu_fd(struct kvm_vcpu *vcpu) { char name[8 + 1 + ITOA_MAX_LEN + 1]; snprintf(name, sizeof(name), "kvm-vcpu:%d", vcpu->vcpu_id); return anon_inode_getfd(name, &kvm_vcpu_fops, vcpu, O_RDWR | O_CLOEXEC); } #ifdef __KVM_HAVE_ARCH_VCPU_DEBUGFS static int vcpu_get_pid(void *data, u64 *val) { struct kvm_vcpu *vcpu = data; rcu_read_lock(); *val = pid_nr(rcu_dereference(vcpu->pid)); rcu_read_unlock(); return 0; } DEFINE_SIMPLE_ATTRIBUTE(vcpu_get_pid_fops, vcpu_get_pid, NULL, "%llu\n"); static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) { struct dentry *debugfs_dentry; char dir_name[ITOA_MAX_LEN * 2]; if (!debugfs_initialized()) return; snprintf(dir_name, sizeof(dir_name), "vcpu%d", vcpu->vcpu_id); debugfs_dentry = debugfs_create_dir(dir_name, vcpu->kvm->debugfs_dentry); debugfs_create_file("pid", 0444, debugfs_dentry, vcpu, &vcpu_get_pid_fops); kvm_arch_create_vcpu_debugfs(vcpu, debugfs_dentry); } #endif /* * Creates some virtual cpus. Good luck creating more than one. */ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id) { int r; struct kvm_vcpu *vcpu; struct page *page; /* * KVM tracks vCPU IDs as 'int', be kind to userspace and reject * too-large values instead of silently truncating. * * Ensure KVM_MAX_VCPU_IDS isn't pushed above INT_MAX without first * changing the storage type (at the very least, IDs should be tracked * as unsigned ints). */ BUILD_BUG_ON(KVM_MAX_VCPU_IDS > INT_MAX); if (id >= KVM_MAX_VCPU_IDS) return -EINVAL; mutex_lock(&kvm->lock); if (kvm->created_vcpus >= kvm->max_vcpus) { mutex_unlock(&kvm->lock); return -EINVAL; } r = kvm_arch_vcpu_precreate(kvm, id); if (r) { mutex_unlock(&kvm->lock); return r; } kvm->created_vcpus++; mutex_unlock(&kvm->lock); vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL_ACCOUNT); if (!vcpu) { r = -ENOMEM; goto vcpu_decrement; } BUILD_BUG_ON(sizeof(struct kvm_run) > PAGE_SIZE); page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); if (!page) { r = -ENOMEM; goto vcpu_free; } vcpu->run = page_address(page); kvm_vcpu_init(vcpu, kvm, id); r = kvm_arch_vcpu_create(vcpu); if (r) goto vcpu_free_run_page; if (kvm->dirty_ring_size) { r = kvm_dirty_ring_alloc(&vcpu->dirty_ring, id, kvm->dirty_ring_size); if (r) goto arch_vcpu_destroy; } mutex_lock(&kvm->lock); #ifdef CONFIG_LOCKDEP /* Ensure that lockdep knows vcpu->mutex is taken *inside* kvm->lock */ mutex_lock(&vcpu->mutex); mutex_unlock(&vcpu->mutex); #endif if (kvm_get_vcpu_by_id(kvm, id)) { r = -EEXIST; goto unlock_vcpu_destroy; } vcpu->vcpu_idx = atomic_read(&kvm->online_vcpus); r = xa_reserve(&kvm->vcpu_array, vcpu->vcpu_idx, GFP_KERNEL_ACCOUNT); if (r) goto unlock_vcpu_destroy; /* Now it's all set up, let userspace reach it */ kvm_get_kvm(kvm); r = create_vcpu_fd(vcpu); if (r < 0) goto kvm_put_xa_release; if (KVM_BUG_ON(xa_store(&kvm->vcpu_array, vcpu->vcpu_idx, vcpu, 0), kvm)) { r = -EINVAL; goto kvm_put_xa_release; } /* * Pairs with smp_rmb() in kvm_get_vcpu. Store the vcpu * pointer before kvm->online_vcpu's incremented value. */ smp_wmb(); atomic_inc(&kvm->online_vcpus); mutex_unlock(&kvm->lock); kvm_arch_vcpu_postcreate(vcpu); kvm_create_vcpu_debugfs(vcpu); return r; kvm_put_xa_release: kvm_put_kvm_no_destroy(kvm); xa_release(&kvm->vcpu_array, vcpu->vcpu_idx); unlock_vcpu_destroy: mutex_unlock(&kvm->lock); kvm_dirty_ring_free(&vcpu->dirty_ring); arch_vcpu_destroy: kvm_arch_vcpu_destroy(vcpu); vcpu_free_run_page: free_page((unsigned long)vcpu->run); vcpu_free: kmem_cache_free(kvm_vcpu_cache, vcpu); vcpu_decrement: mutex_lock(&kvm->lock); kvm->created_vcpus--; mutex_unlock(&kvm->lock); return r; } static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset) { if (sigset) { sigdelsetmask(sigset, sigmask(SIGKILL)|sigmask(SIGSTOP)); vcpu->sigset_active = 1; vcpu->sigset = *sigset; } else vcpu->sigset_active = 0; return 0; } static ssize_t kvm_vcpu_stats_read(struct file *file, char __user *user_buffer, size_t size, loff_t *offset) { struct kvm_vcpu *vcpu = file->private_data; return kvm_stats_read(vcpu->stats_id, &kvm_vcpu_stats_header, &kvm_vcpu_stats_desc[0], &vcpu->stat, sizeof(vcpu->stat), user_buffer, size, offset); } static int kvm_vcpu_stats_release(struct inode *inode, struct file *file) { struct kvm_vcpu *vcpu = file->private_data; kvm_put_kvm(vcpu->kvm); return 0; } static const struct file_operations kvm_vcpu_stats_fops = { .owner = THIS_MODULE, .read = kvm_vcpu_stats_read, .release = kvm_vcpu_stats_release, .llseek = noop_llseek, }; static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu *vcpu) { int fd; struct file *file; char name[15 + ITOA_MAX_LEN + 1]; snprintf(name, sizeof(name), "kvm-vcpu-stats:%d", vcpu->vcpu_id); fd = get_unused_fd_flags(O_CLOEXEC); if (fd < 0) return fd; file = anon_inode_getfile(name, &kvm_vcpu_stats_fops, vcpu, O_RDONLY); if (IS_ERR(file)) { put_unused_fd(fd); return PTR_ERR(file); } kvm_get_kvm(vcpu->kvm); file->f_mode |= FMODE_PREAD; fd_install(fd, file); return fd; } #ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY static int kvm_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, struct kvm_pre_fault_memory *range) { int idx; long r; u64 full_size; if (range->flags) return -EINVAL; if (!PAGE_ALIGNED(range->gpa) || !PAGE_ALIGNED(range->size) || range->gpa + range->size <= range->gpa) return -EINVAL; vcpu_load(vcpu); idx = srcu_read_lock(&vcpu->kvm->srcu); full_size = range->size; do { if (signal_pending(current)) { r = -EINTR; break; } r = kvm_arch_vcpu_pre_fault_memory(vcpu, range); if (WARN_ON_ONCE(r == 0 || r == -EIO)) break; if (r < 0) break; range->size -= r; range->gpa += r; cond_resched(); } while (range->size); srcu_read_unlock(&vcpu->kvm->srcu, idx); vcpu_put(vcpu); /* Return success if at least one page was mapped successfully. */ return full_size == range->size ? r : 0; } #endif static long kvm_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm_vcpu *vcpu = filp->private_data; void __user *argp = (void __user *)arg; int r; struct kvm_fpu *fpu = NULL; struct kvm_sregs *kvm_sregs = NULL; if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_dead) return -EIO; if (unlikely(_IOC_TYPE(ioctl) != KVMIO)) return -EINVAL; /* * Some architectures have vcpu ioctls that are asynchronous to vcpu * execution; mutex_lock() would break them. */ r = kvm_arch_vcpu_async_ioctl(filp, ioctl, arg); if (r != -ENOIOCTLCMD) return r; if (mutex_lock_killable(&vcpu->mutex)) return -EINTR; switch (ioctl) { case KVM_RUN: { struct pid *oldpid; r = -EINVAL; if (arg) goto out; oldpid = rcu_access_pointer(vcpu->pid); if (unlikely(oldpid != task_pid(current))) { /* The thread running this VCPU changed. */ struct pid *newpid; r = kvm_arch_vcpu_run_pid_change(vcpu); if (r) break; newpid = get_task_pid(current, PIDTYPE_PID); rcu_assign_pointer(vcpu->pid, newpid); if (oldpid) synchronize_rcu(); put_pid(oldpid); } vcpu->wants_to_run = !READ_ONCE(vcpu->run->immediate_exit__unsafe); r = kvm_arch_vcpu_ioctl_run(vcpu); vcpu->wants_to_run = false; trace_kvm_userspace_exit(vcpu->run->exit_reason, r); break; } case KVM_GET_REGS: { struct kvm_regs *kvm_regs; r = -ENOMEM; kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL); if (!kvm_regs) goto out; r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs); if (r) goto out_free1; r = -EFAULT; if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs))) goto out_free1; r = 0; out_free1: kfree(kvm_regs); break; } case KVM_SET_REGS: { struct kvm_regs *kvm_regs; kvm_regs = memdup_user(argp, sizeof(*kvm_regs)); if (IS_ERR(kvm_regs)) { r = PTR_ERR(kvm_regs); goto out; } r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs); kfree(kvm_regs); break; } case KVM_GET_SREGS: { kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL); r = -ENOMEM; if (!kvm_sregs) goto out; r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs))) goto out; r = 0; break; } case KVM_SET_SREGS: { kvm_sregs = memdup_user(argp, sizeof(*kvm_sregs)); if (IS_ERR(kvm_sregs)) { r = PTR_ERR(kvm_sregs); kvm_sregs = NULL; goto out; } r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs); break; } case KVM_GET_MP_STATE: { struct kvm_mp_state mp_state; r = kvm_arch_vcpu_ioctl_get_mpstate(vcpu, &mp_state); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, &mp_state, sizeof(mp_state))) goto out; r = 0; break; } case KVM_SET_MP_STATE: { struct kvm_mp_state mp_state; r = -EFAULT; if (copy_from_user(&mp_state, argp, sizeof(mp_state))) goto out; r = kvm_arch_vcpu_ioctl_set_mpstate(vcpu, &mp_state); break; } case KVM_TRANSLATE: { struct kvm_translation tr; r = -EFAULT; if (copy_from_user(&tr, argp, sizeof(tr))) goto out; r = kvm_arch_vcpu_ioctl_translate(vcpu, &tr); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, &tr, sizeof(tr))) goto out; r = 0; break; } case KVM_SET_GUEST_DEBUG: { struct kvm_guest_debug dbg; r = -EFAULT; if (copy_from_user(&dbg, argp, sizeof(dbg))) goto out; r = kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg); break; } case KVM_SET_SIGNAL_MASK: { struct kvm_signal_mask __user *sigmask_arg = argp; struct kvm_signal_mask kvm_sigmask; sigset_t sigset, *p; p = NULL; if (argp) { r = -EFAULT; if (copy_from_user(&kvm_sigmask, argp, sizeof(kvm_sigmask))) goto out; r = -EINVAL; if (kvm_sigmask.len != sizeof(sigset)) goto out; r = -EFAULT; if (copy_from_user(&sigset, sigmask_arg->sigset, sizeof(sigset))) goto out; p = &sigset; } r = kvm_vcpu_ioctl_set_sigmask(vcpu, p); break; } case KVM_GET_FPU: { fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL); r = -ENOMEM; if (!fpu) goto out; r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu))) goto out; r = 0; break; } case KVM_SET_FPU: { fpu = memdup_user(argp, sizeof(*fpu)); if (IS_ERR(fpu)) { r = PTR_ERR(fpu); fpu = NULL; goto out; } r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu); break; } case KVM_GET_STATS_FD: { r = kvm_vcpu_ioctl_get_stats_fd(vcpu); break; } #ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY case KVM_PRE_FAULT_MEMORY: { struct kvm_pre_fault_memory range; r = -EFAULT; if (copy_from_user(&range, argp, sizeof(range))) break; r = kvm_vcpu_pre_fault_memory(vcpu, &range); /* Pass back leftover range. */ if (copy_to_user(argp, &range, sizeof(range))) r = -EFAULT; break; } #endif default: r = kvm_arch_vcpu_ioctl(filp, ioctl, arg); } out: mutex_unlock(&vcpu->mutex); kfree(fpu); kfree(kvm_sregs); return r; } #ifdef CONFIG_KVM_COMPAT static long kvm_vcpu_compat_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm_vcpu *vcpu = filp->private_data; void __user *argp = compat_ptr(arg); int r; if (vcpu->kvm->mm != current->mm || vcpu->kvm->vm_dead) return -EIO; switch (ioctl) { case KVM_SET_SIGNAL_MASK: { struct kvm_signal_mask __user *sigmask_arg = argp; struct kvm_signal_mask kvm_sigmask; sigset_t sigset; if (argp) { r = -EFAULT; if (copy_from_user(&kvm_sigmask, argp, sizeof(kvm_sigmask))) goto out; r = -EINVAL; if (kvm_sigmask.len != sizeof(compat_sigset_t)) goto out; r = -EFAULT; if (get_compat_sigset(&sigset, (compat_sigset_t __user *)sigmask_arg->sigset)) goto out; r = kvm_vcpu_ioctl_set_sigmask(vcpu, &sigset); } else r = kvm_vcpu_ioctl_set_sigmask(vcpu, NULL); break; } default: r = kvm_vcpu_ioctl(filp, ioctl, arg); } out: return r; } #endif static int kvm_device_mmap(struct file *filp, struct vm_area_struct *vma) { struct kvm_device *dev = filp->private_data; if (dev->ops->mmap) return dev->ops->mmap(dev, vma); return -ENODEV; } static int kvm_device_ioctl_attr(struct kvm_device *dev, int (*accessor)(struct kvm_device *dev, struct kvm_device_attr *attr), unsigned long arg) { struct kvm_device_attr attr; if (!accessor) return -EPERM; if (copy_from_user(&attr, (void __user *)arg, sizeof(attr))) return -EFAULT; return accessor(dev, &attr); } static long kvm_device_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm_device *dev = filp->private_data; if (dev->kvm->mm != current->mm || dev->kvm->vm_dead) return -EIO; switch (ioctl) { case KVM_SET_DEVICE_ATTR: return kvm_device_ioctl_attr(dev, dev->ops->set_attr, arg); case KVM_GET_DEVICE_ATTR: return kvm_device_ioctl_attr(dev, dev->ops->get_attr, arg); case KVM_HAS_DEVICE_ATTR: return kvm_device_ioctl_attr(dev, dev->ops->has_attr, arg); default: if (dev->ops->ioctl) return dev->ops->ioctl(dev, ioctl, arg); return -ENOTTY; } } static int kvm_device_release(struct inode *inode, struct file *filp) { struct kvm_device *dev = filp->private_data; struct kvm *kvm = dev->kvm; if (dev->ops->release) { mutex_lock(&kvm->lock); list_del_rcu(&dev->vm_node); synchronize_rcu(); dev->ops->release(dev); mutex_unlock(&kvm->lock); } kvm_put_kvm(kvm); return 0; } static struct file_operations kvm_device_fops = { .unlocked_ioctl = kvm_device_ioctl, .release = kvm_device_release, KVM_COMPAT(kvm_device_ioctl), .mmap = kvm_device_mmap, }; struct kvm_device *kvm_device_from_filp(struct file *filp) { if (filp->f_op != &kvm_device_fops) return NULL; return filp->private_data; } static const struct kvm_device_ops *kvm_device_ops_table[KVM_DEV_TYPE_MAX] = { #ifdef CONFIG_KVM_MPIC [KVM_DEV_TYPE_FSL_MPIC_20] = &kvm_mpic_ops, [KVM_DEV_TYPE_FSL_MPIC_42] = &kvm_mpic_ops, #endif }; int kvm_register_device_ops(const struct kvm_device_ops *ops, u32 type) { if (type >= ARRAY_SIZE(kvm_device_ops_table)) return -ENOSPC; if (kvm_device_ops_table[type] != NULL) return -EEXIST; kvm_device_ops_table[type] = ops; return 0; } void kvm_unregister_device_ops(u32 type) { if (kvm_device_ops_table[type] != NULL) kvm_device_ops_table[type] = NULL; } static int kvm_ioctl_create_device(struct kvm *kvm, struct kvm_create_device *cd) { const struct kvm_device_ops *ops; struct kvm_device *dev; bool test = cd->flags & KVM_CREATE_DEVICE_TEST; int type; int ret; if (cd->type >= ARRAY_SIZE(kvm_device_ops_table)) return -ENODEV; type = array_index_nospec(cd->type, ARRAY_SIZE(kvm_device_ops_table)); ops = kvm_device_ops_table[type]; if (ops == NULL) return -ENODEV; if (test) return 0; dev = kzalloc(sizeof(*dev), GFP_KERNEL_ACCOUNT); if (!dev) return -ENOMEM; dev->ops = ops; dev->kvm = kvm; mutex_lock(&kvm->lock); ret = ops->create(dev, type); if (ret < 0) { mutex_unlock(&kvm->lock); kfree(dev); return ret; } list_add_rcu(&dev->vm_node, &kvm->devices); mutex_unlock(&kvm->lock); if (ops->init) ops->init(dev); kvm_get_kvm(kvm); ret = anon_inode_getfd(ops->name, &kvm_device_fops, dev, O_RDWR | O_CLOEXEC); if (ret < 0) { kvm_put_kvm_no_destroy(kvm); mutex_lock(&kvm->lock); list_del_rcu(&dev->vm_node); synchronize_rcu(); if (ops->release) ops->release(dev); mutex_unlock(&kvm->lock); if (ops->destroy) ops->destroy(dev); return ret; } cd->fd = ret; return 0; } static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg) { switch (arg) { case KVM_CAP_USER_MEMORY: case KVM_CAP_USER_MEMORY2: case KVM_CAP_DESTROY_MEMORY_REGION_WORKS: case KVM_CAP_JOIN_MEMORY_REGIONS_WORKS: case KVM_CAP_INTERNAL_ERROR_DATA: #ifdef CONFIG_HAVE_KVM_MSI case KVM_CAP_SIGNAL_MSI: #endif #ifdef CONFIG_HAVE_KVM_IRQCHIP case KVM_CAP_IRQFD: #endif case KVM_CAP_IOEVENTFD_ANY_LENGTH: case KVM_CAP_CHECK_EXTENSION_VM: case KVM_CAP_ENABLE_CAP_VM: case KVM_CAP_HALT_POLL: return 1; #ifdef CONFIG_KVM_MMIO case KVM_CAP_COALESCED_MMIO: return KVM_COALESCED_MMIO_PAGE_OFFSET; case KVM_CAP_COALESCED_PIO: return 1; #endif #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: return KVM_DIRTY_LOG_MANUAL_CAPS; #endif #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING case KVM_CAP_IRQ_ROUTING: return KVM_MAX_IRQ_ROUTES; #endif #if KVM_MAX_NR_ADDRESS_SPACES > 1 case KVM_CAP_MULTI_ADDRESS_SPACE: if (kvm) return kvm_arch_nr_memslot_as_ids(kvm); return KVM_MAX_NR_ADDRESS_SPACES; #endif case KVM_CAP_NR_MEMSLOTS: return KVM_USER_MEM_SLOTS; case KVM_CAP_DIRTY_LOG_RING: #ifdef CONFIG_HAVE_KVM_DIRTY_RING_TSO return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn); #else return 0; #endif case KVM_CAP_DIRTY_LOG_RING_ACQ_REL: #ifdef CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL return KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn); #else return 0; #endif #ifdef CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP: #endif case KVM_CAP_BINARY_STATS_FD: case KVM_CAP_SYSTEM_EVENT_DATA: case KVM_CAP_DEVICE_CTRL: return 1; #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES case KVM_CAP_MEMORY_ATTRIBUTES: return kvm_supported_mem_attributes(kvm); #endif #ifdef CONFIG_KVM_PRIVATE_MEM case KVM_CAP_GUEST_MEMFD: return !kvm || kvm_arch_has_private_mem(kvm); #endif default: break; } return kvm_vm_ioctl_check_extension(kvm, arg); } static int kvm_vm_ioctl_enable_dirty_log_ring(struct kvm *kvm, u32 size) { int r; if (!KVM_DIRTY_LOG_PAGE_OFFSET) return -EINVAL; /* the size should be power of 2 */ if (!size || (size & (size - 1))) return -EINVAL; /* Should be bigger to keep the reserved entries, or a page */ if (size < kvm_dirty_ring_get_rsvd_entries() * sizeof(struct kvm_dirty_gfn) || size < PAGE_SIZE) return -EINVAL; if (size > KVM_DIRTY_RING_MAX_ENTRIES * sizeof(struct kvm_dirty_gfn)) return -E2BIG; /* We only allow it to set once */ if (kvm->dirty_ring_size) return -EINVAL; mutex_lock(&kvm->lock); if (kvm->created_vcpus) { /* We don't allow to change this value after vcpu created */ r = -EINVAL; } else { kvm->dirty_ring_size = size; r = 0; } mutex_unlock(&kvm->lock); return r; } static int kvm_vm_ioctl_reset_dirty_pages(struct kvm *kvm) { unsigned long i; struct kvm_vcpu *vcpu; int cleared = 0; if (!kvm->dirty_ring_size) return -EINVAL; mutex_lock(&kvm->slots_lock); kvm_for_each_vcpu(i, vcpu, kvm) cleared += kvm_dirty_ring_reset(vcpu->kvm, &vcpu->dirty_ring); mutex_unlock(&kvm->slots_lock); if (cleared) kvm_flush_remote_tlbs(kvm); return cleared; } int __attribute__((weak)) kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) { return -EINVAL; } bool kvm_are_all_memslots_empty(struct kvm *kvm) { int i; lockdep_assert_held(&kvm->slots_lock); for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) { if (!kvm_memslots_empty(__kvm_memslots(kvm, i))) return false; } return true; } EXPORT_SYMBOL_GPL(kvm_are_all_memslots_empty); static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm, struct kvm_enable_cap *cap) { switch (cap->cap) { #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT case KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2: { u64 allowed_options = KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE; if (cap->args[0] & KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE) allowed_options = KVM_DIRTY_LOG_MANUAL_CAPS; if (cap->flags || (cap->args[0] & ~allowed_options)) return -EINVAL; kvm->manual_dirty_log_protect = cap->args[0]; return 0; } #endif case KVM_CAP_HALT_POLL: { if (cap->flags || cap->args[0] != (unsigned int)cap->args[0]) return -EINVAL; kvm->max_halt_poll_ns = cap->args[0]; /* * Ensure kvm->override_halt_poll_ns does not become visible * before kvm->max_halt_poll_ns. * * Pairs with the smp_rmb() in kvm_vcpu_max_halt_poll_ns(). */ smp_wmb(); kvm->override_halt_poll_ns = true; return 0; } case KVM_CAP_DIRTY_LOG_RING: case KVM_CAP_DIRTY_LOG_RING_ACQ_REL: if (!kvm_vm_ioctl_check_extension_generic(kvm, cap->cap)) return -EINVAL; return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]); case KVM_CAP_DIRTY_LOG_RING_WITH_BITMAP: { int r = -EINVAL; if (!IS_ENABLED(CONFIG_NEED_KVM_DIRTY_RING_WITH_BITMAP) || !kvm->dirty_ring_size || cap->flags) return r; mutex_lock(&kvm->slots_lock); /* * For simplicity, allow enabling ring+bitmap if and only if * there are no memslots, e.g. to ensure all memslots allocate * a bitmap after the capability is enabled. */ if (kvm_are_all_memslots_empty(kvm)) { kvm->dirty_ring_with_bitmap = true; r = 0; } mutex_unlock(&kvm->slots_lock); return r; } default: return kvm_vm_ioctl_enable_cap(kvm, cap); } } static ssize_t kvm_vm_stats_read(struct file *file, char __user *user_buffer, size_t size, loff_t *offset) { struct kvm *kvm = file->private_data; return kvm_stats_read(kvm->stats_id, &kvm_vm_stats_header, &kvm_vm_stats_desc[0], &kvm->stat, sizeof(kvm->stat), user_buffer, size, offset); } static int kvm_vm_stats_release(struct inode *inode, struct file *file) { struct kvm *kvm = file->private_data; kvm_put_kvm(kvm); return 0; } static const struct file_operations kvm_vm_stats_fops = { .owner = THIS_MODULE, .read = kvm_vm_stats_read, .release = kvm_vm_stats_release, .llseek = noop_llseek, }; static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm) { int fd; struct file *file; fd = get_unused_fd_flags(O_CLOEXEC); if (fd < 0) return fd; file = anon_inode_getfile("kvm-vm-stats", &kvm_vm_stats_fops, kvm, O_RDONLY); if (IS_ERR(file)) { put_unused_fd(fd); return PTR_ERR(file); } kvm_get_kvm(kvm); file->f_mode |= FMODE_PREAD; fd_install(fd, file); return fd; } #define SANITY_CHECK_MEM_REGION_FIELD(field) \ do { \ BUILD_BUG_ON(offsetof(struct kvm_userspace_memory_region, field) != \ offsetof(struct kvm_userspace_memory_region2, field)); \ BUILD_BUG_ON(sizeof_field(struct kvm_userspace_memory_region, field) != \ sizeof_field(struct kvm_userspace_memory_region2, field)); \ } while (0) static long kvm_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm *kvm = filp->private_data; void __user *argp = (void __user *)arg; int r; if (kvm->mm != current->mm || kvm->vm_dead) return -EIO; switch (ioctl) { case KVM_CREATE_VCPU: r = kvm_vm_ioctl_create_vcpu(kvm, arg); break; case KVM_ENABLE_CAP: { struct kvm_enable_cap cap; r = -EFAULT; if (copy_from_user(&cap, argp, sizeof(cap))) goto out; r = kvm_vm_ioctl_enable_cap_generic(kvm, &cap); break; } case KVM_SET_USER_MEMORY_REGION2: case KVM_SET_USER_MEMORY_REGION: { struct kvm_userspace_memory_region2 mem; unsigned long size; if (ioctl == KVM_SET_USER_MEMORY_REGION) { /* * Fields beyond struct kvm_userspace_memory_region shouldn't be * accessed, but avoid leaking kernel memory in case of a bug. */ memset(&mem, 0, sizeof(mem)); size = sizeof(struct kvm_userspace_memory_region); } else { size = sizeof(struct kvm_userspace_memory_region2); } /* Ensure the common parts of the two structs are identical. */ SANITY_CHECK_MEM_REGION_FIELD(slot); SANITY_CHECK_MEM_REGION_FIELD(flags); SANITY_CHECK_MEM_REGION_FIELD(guest_phys_addr); SANITY_CHECK_MEM_REGION_FIELD(memory_size); SANITY_CHECK_MEM_REGION_FIELD(userspace_addr); r = -EFAULT; if (copy_from_user(&mem, argp, size)) goto out; r = -EINVAL; if (ioctl == KVM_SET_USER_MEMORY_REGION && (mem.flags & ~KVM_SET_USER_MEMORY_REGION_V1_FLAGS)) goto out; r = kvm_vm_ioctl_set_memory_region(kvm, &mem); break; } case KVM_GET_DIRTY_LOG: { struct kvm_dirty_log log; r = -EFAULT; if (copy_from_user(&log, argp, sizeof(log))) goto out; r = kvm_vm_ioctl_get_dirty_log(kvm, &log); break; } #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT case KVM_CLEAR_DIRTY_LOG: { struct kvm_clear_dirty_log log; r = -EFAULT; if (copy_from_user(&log, argp, sizeof(log))) goto out; r = kvm_vm_ioctl_clear_dirty_log(kvm, &log); break; } #endif #ifdef CONFIG_KVM_MMIO case KVM_REGISTER_COALESCED_MMIO: { struct kvm_coalesced_mmio_zone zone; r = -EFAULT; if (copy_from_user(&zone, argp, sizeof(zone))) goto out; r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone); break; } case KVM_UNREGISTER_COALESCED_MMIO: { struct kvm_coalesced_mmio_zone zone; r = -EFAULT; if (copy_from_user(&zone, argp, sizeof(zone))) goto out; r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone); break; } #endif case KVM_IRQFD: { struct kvm_irqfd data; r = -EFAULT; if (copy_from_user(&data, argp, sizeof(data))) goto out; r = kvm_irqfd(kvm, &data); break; } case KVM_IOEVENTFD: { struct kvm_ioeventfd data; r = -EFAULT; if (copy_from_user(&data, argp, sizeof(data))) goto out; r = kvm_ioeventfd(kvm, &data); break; } #ifdef CONFIG_HAVE_KVM_MSI case KVM_SIGNAL_MSI: { struct kvm_msi msi; r = -EFAULT; if (copy_from_user(&msi, argp, sizeof(msi))) goto out; r = kvm_send_userspace_msi(kvm, &msi); break; } #endif #ifdef __KVM_HAVE_IRQ_LINE case KVM_IRQ_LINE_STATUS: case KVM_IRQ_LINE: { struct kvm_irq_level irq_event; r = -EFAULT; if (copy_from_user(&irq_event, argp, sizeof(irq_event))) goto out; r = kvm_vm_ioctl_irq_line(kvm, &irq_event, ioctl == KVM_IRQ_LINE_STATUS); if (r) goto out; r = -EFAULT; if (ioctl == KVM_IRQ_LINE_STATUS) { if (copy_to_user(argp, &irq_event, sizeof(irq_event))) goto out; } r = 0; break; } #endif #ifdef CONFIG_HAVE_KVM_IRQ_ROUTING case KVM_SET_GSI_ROUTING: { struct kvm_irq_routing routing; struct kvm_irq_routing __user *urouting; struct kvm_irq_routing_entry *entries = NULL; r = -EFAULT; if (copy_from_user(&routing, argp, sizeof(routing))) goto out; r = -EINVAL; if (!kvm_arch_can_set_irq_routing(kvm)) goto out; if (routing.nr > KVM_MAX_IRQ_ROUTES) goto out; if (routing.flags) goto out; if (routing.nr) { urouting = argp; entries = vmemdup_array_user(urouting->entries, routing.nr, sizeof(*entries)); if (IS_ERR(entries)) { r = PTR_ERR(entries); goto out; } } r = kvm_set_irq_routing(kvm, entries, routing.nr, routing.flags); kvfree(entries); break; } #endif /* CONFIG_HAVE_KVM_IRQ_ROUTING */ #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES case KVM_SET_MEMORY_ATTRIBUTES: { struct kvm_memory_attributes attrs; r = -EFAULT; if (copy_from_user(&attrs, argp, sizeof(attrs))) goto out; r = kvm_vm_ioctl_set_mem_attributes(kvm, &attrs); break; } #endif /* CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES */ case KVM_CREATE_DEVICE: { struct kvm_create_device cd; r = -EFAULT; if (copy_from_user(&cd, argp, sizeof(cd))) goto out; r = kvm_ioctl_create_device(kvm, &cd); if (r) goto out; r = -EFAULT; if (copy_to_user(argp, &cd, sizeof(cd))) goto out; r = 0; break; } case KVM_CHECK_EXTENSION: r = kvm_vm_ioctl_check_extension_generic(kvm, arg); break; case KVM_RESET_DIRTY_RINGS: r = kvm_vm_ioctl_reset_dirty_pages(kvm); break; case KVM_GET_STATS_FD: r = kvm_vm_ioctl_get_stats_fd(kvm); break; #ifdef CONFIG_KVM_PRIVATE_MEM case KVM_CREATE_GUEST_MEMFD: { struct kvm_create_guest_memfd guest_memfd; r = -EFAULT; if (copy_from_user(&guest_memfd, argp, sizeof(guest_memfd))) goto out; r = kvm_gmem_create(kvm, &guest_memfd); break; } #endif default: r = kvm_arch_vm_ioctl(filp, ioctl, arg); } out: return r; } #ifdef CONFIG_KVM_COMPAT struct compat_kvm_dirty_log { __u32 slot; __u32 padding1; union { compat_uptr_t dirty_bitmap; /* one bit per page */ __u64 padding2; }; }; struct compat_kvm_clear_dirty_log { __u32 slot; __u32 num_pages; __u64 first_page; union { compat_uptr_t dirty_bitmap; /* one bit per page */ __u64 padding2; }; }; long __weak kvm_arch_vm_compat_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { return -ENOTTY; } static long kvm_vm_compat_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { struct kvm *kvm = filp->private_data; int r; if (kvm->mm != current->mm || kvm->vm_dead) return -EIO; r = kvm_arch_vm_compat_ioctl(filp, ioctl, arg); if (r != -ENOTTY) return r; switch (ioctl) { #ifdef CONFIG_KVM_GENERIC_DIRTYLOG_READ_PROTECT case KVM_CLEAR_DIRTY_LOG: { struct compat_kvm_clear_dirty_log compat_log; struct kvm_clear_dirty_log log; if (copy_from_user(&compat_log, (void __user *)arg, sizeof(compat_log))) return -EFAULT; log.slot = compat_log.slot; log.num_pages = compat_log.num_pages; log.first_page = compat_log.first_page; log.padding2 = compat_log.padding2; log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap); r = kvm_vm_ioctl_clear_dirty_log(kvm, &log); break; } #endif case KVM_GET_DIRTY_LOG: { struct compat_kvm_dirty_log compat_log; struct kvm_dirty_log log; if (copy_from_user(&compat_log, (void __user *)arg, sizeof(compat_log))) return -EFAULT; log.slot = compat_log.slot; log.padding1 = compat_log.padding1; log.padding2 = compat_log.padding2; log.dirty_bitmap = compat_ptr(compat_log.dirty_bitmap); r = kvm_vm_ioctl_get_dirty_log(kvm, &log); break; } default: r = kvm_vm_ioctl(filp, ioctl, arg); } return r; } #endif static struct file_operations kvm_vm_fops = { .release = kvm_vm_release, .unlocked_ioctl = kvm_vm_ioctl, .llseek = noop_llseek, KVM_COMPAT(kvm_vm_compat_ioctl), }; bool file_is_kvm(struct file *file) { return file && file->f_op == &kvm_vm_fops; } EXPORT_SYMBOL_GPL(file_is_kvm); static int kvm_dev_ioctl_create_vm(unsigned long type) { char fdname[ITOA_MAX_LEN + 1]; int r, fd; struct kvm *kvm; struct file *file; fd = get_unused_fd_flags(O_CLOEXEC); if (fd < 0) return fd; snprintf(fdname, sizeof(fdname), "%d", fd); kvm = kvm_create_vm(type, fdname); if (IS_ERR(kvm)) { r = PTR_ERR(kvm); goto put_fd; } file = anon_inode_getfile("kvm-vm", &kvm_vm_fops, kvm, O_RDWR); if (IS_ERR(file)) { r = PTR_ERR(file); goto put_kvm; } /* * Don't call kvm_put_kvm anymore at this point; file->f_op is * already set, with ->release() being kvm_vm_release(). In error * cases it will be called by the final fput(file) and will take * care of doing kvm_put_kvm(kvm). */ kvm_uevent_notify_change(KVM_EVENT_CREATE_VM, kvm); fd_install(fd, file); return fd; put_kvm: kvm_put_kvm(kvm); put_fd: put_unused_fd(fd); return r; } static long kvm_dev_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { int r = -EINVAL; switch (ioctl) { case KVM_GET_API_VERSION: if (arg) goto out; r = KVM_API_VERSION; break; case KVM_CREATE_VM: r = kvm_dev_ioctl_create_vm(arg); break; case KVM_CHECK_EXTENSION: r = kvm_vm_ioctl_check_extension_generic(NULL, arg); break; case KVM_GET_VCPU_MMAP_SIZE: if (arg) goto out; r = PAGE_SIZE; /* struct kvm_run */ #ifdef CONFIG_X86 r += PAGE_SIZE; /* pio data page */ #endif #ifdef CONFIG_KVM_MMIO r += PAGE_SIZE; /* coalesced mmio ring page */ #endif break; default: return kvm_arch_dev_ioctl(filp, ioctl, arg); } out: return r; } static struct file_operations kvm_chardev_ops = { .unlocked_ioctl = kvm_dev_ioctl, .llseek = noop_llseek, KVM_COMPAT(kvm_dev_ioctl), }; static struct miscdevice kvm_dev = { KVM_MINOR, "kvm", &kvm_chardev_ops, }; #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING __visible bool kvm_rebooting; EXPORT_SYMBOL_GPL(kvm_rebooting); static DEFINE_PER_CPU(bool, hardware_enabled); static int kvm_usage_count; static int __hardware_enable_nolock(void) { if (__this_cpu_read(hardware_enabled)) return 0; if (kvm_arch_hardware_enable()) { pr_info("kvm: enabling virtualization on CPU%d failed\n", raw_smp_processor_id()); return -EIO; } __this_cpu_write(hardware_enabled, true); return 0; } static void hardware_enable_nolock(void *failed) { if (__hardware_enable_nolock()) atomic_inc(failed); } static int kvm_online_cpu(unsigned int cpu) { int ret = 0; /* * Abort the CPU online process if hardware virtualization cannot * be enabled. Otherwise running VMs would encounter unrecoverable * errors when scheduled to this CPU. */ mutex_lock(&kvm_lock); if (kvm_usage_count) ret = __hardware_enable_nolock(); mutex_unlock(&kvm_lock); return ret; } static void hardware_disable_nolock(void *junk) { /* * Note, hardware_disable_all_nolock() tells all online CPUs to disable * hardware, not just CPUs that successfully enabled hardware! */ if (!__this_cpu_read(hardware_enabled)) return; kvm_arch_hardware_disable(); __this_cpu_write(hardware_enabled, false); } static int kvm_offline_cpu(unsigned int cpu) { mutex_lock(&kvm_lock); if (kvm_usage_count) hardware_disable_nolock(NULL); mutex_unlock(&kvm_lock); return 0; } static void hardware_disable_all_nolock(void) { BUG_ON(!kvm_usage_count); kvm_usage_count--; if (!kvm_usage_count) on_each_cpu(hardware_disable_nolock, NULL, 1); } static void hardware_disable_all(void) { cpus_read_lock(); mutex_lock(&kvm_lock); hardware_disable_all_nolock(); mutex_unlock(&kvm_lock); cpus_read_unlock(); } static int hardware_enable_all(void) { atomic_t failed = ATOMIC_INIT(0); int r; /* * Do not enable hardware virtualization if the system is going down. * If userspace initiated a forced reboot, e.g. reboot -f, then it's * possible for an in-flight KVM_CREATE_VM to trigger hardware enabling * after kvm_reboot() is called. Note, this relies on system_state * being set _before_ kvm_reboot(), which is why KVM uses a syscore ops * hook instead of registering a dedicated reboot notifier (the latter * runs before system_state is updated). */ if (system_state == SYSTEM_HALT || system_state == SYSTEM_POWER_OFF || system_state == SYSTEM_RESTART) return -EBUSY; /* * When onlining a CPU, cpu_online_mask is set before kvm_online_cpu() * is called, and so on_each_cpu() between them includes the CPU that * is being onlined. As a result, hardware_enable_nolock() may get * invoked before kvm_online_cpu(), which also enables hardware if the * usage count is non-zero. Disable CPU hotplug to avoid attempting to * enable hardware multiple times. */ cpus_read_lock(); mutex_lock(&kvm_lock); r = 0; kvm_usage_count++; if (kvm_usage_count == 1) { on_each_cpu(hardware_enable_nolock, &failed, 1); if (atomic_read(&failed)) { hardware_disable_all_nolock(); r = -EBUSY; } } mutex_unlock(&kvm_lock); cpus_read_unlock(); return r; } static void kvm_shutdown(void) { /* * Disable hardware virtualization and set kvm_rebooting to indicate * that KVM has asynchronously disabled hardware virtualization, i.e. * that relevant errors and exceptions aren't entirely unexpected. * Some flavors of hardware virtualization need to be disabled before * transferring control to firmware (to perform shutdown/reboot), e.g. * on x86, virtualization can block INIT interrupts, which are used by * firmware to pull APs back under firmware control. Note, this path * is used for both shutdown and reboot scenarios, i.e. neither name is * 100% comprehensive. */ pr_info("kvm: exiting hardware virtualization\n"); kvm_rebooting = true; on_each_cpu(hardware_disable_nolock, NULL, 1); } static int kvm_suspend(void) { /* * Secondary CPUs and CPU hotplug are disabled across the suspend/resume * callbacks, i.e. no need to acquire kvm_lock to ensure the usage count * is stable. Assert that kvm_lock is not held to ensure the system * isn't suspended while KVM is enabling hardware. Hardware enabling * can be preempted, but the task cannot be frozen until it has dropped * all locks (userspace tasks are frozen via a fake signal). */ lockdep_assert_not_held(&kvm_lock); lockdep_assert_irqs_disabled(); if (kvm_usage_count) hardware_disable_nolock(NULL); return 0; } static void kvm_resume(void) { lockdep_assert_not_held(&kvm_lock); lockdep_assert_irqs_disabled(); if (kvm_usage_count) WARN_ON_ONCE(__hardware_enable_nolock()); } static struct syscore_ops kvm_syscore_ops = { .suspend = kvm_suspend, .resume = kvm_resume, .shutdown = kvm_shutdown, }; #else /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */ static int hardware_enable_all(void) { return 0; } static void hardware_disable_all(void) { } #endif /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */ static void kvm_iodevice_destructor(struct kvm_io_device *dev) { if (dev->ops->destructor) dev->ops->destructor(dev); } static void kvm_io_bus_destroy(struct kvm_io_bus *bus) { int i; for (i = 0; i < bus->dev_count; i++) { struct kvm_io_device *pos = bus->range[i].dev; kvm_iodevice_destructor(pos); } kfree(bus); } static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1, const struct kvm_io_range *r2) { gpa_t addr1 = r1->addr; gpa_t addr2 = r2->addr; if (addr1 < addr2) return -1; /* If r2->len == 0, match the exact address. If r2->len != 0, * accept any overlapping write. Any order is acceptable for * overlapping ranges, because kvm_io_bus_get_first_dev ensures * we process all of them. */ if (r2->len) { addr1 += r1->len; addr2 += r2->len; } if (addr1 > addr2) return 1; return 0; } static int kvm_io_bus_sort_cmp(const void *p1, const void *p2) { return kvm_io_bus_cmp(p1, p2); } static int kvm_io_bus_get_first_dev(struct kvm_io_bus *bus, gpa_t addr, int len) { struct kvm_io_range *range, key; int off; key = (struct kvm_io_range) { .addr = addr, .len = len, }; range = bsearch(&key, bus->range, bus->dev_count, sizeof(struct kvm_io_range), kvm_io_bus_sort_cmp); if (range == NULL) return -ENOENT; off = range - bus->range; while (off > 0 && kvm_io_bus_cmp(&key, &bus->range[off-1]) == 0) off--; return off; } static int __kvm_io_bus_write(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus, struct kvm_io_range *range, const void *val) { int idx; idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); if (idx < 0) return -EOPNOTSUPP; while (idx < bus->dev_count && kvm_io_bus_cmp(range, &bus->range[idx]) == 0) { if (!kvm_iodevice_write(vcpu, bus->range[idx].dev, range->addr, range->len, val)) return idx; idx++; } return -EOPNOTSUPP; } /* kvm_io_bus_write - called under kvm->slots_lock */ int kvm_io_bus_write(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val) { struct kvm_io_bus *bus; struct kvm_io_range range; int r; range = (struct kvm_io_range) { .addr = addr, .len = len, }; bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); if (!bus) return -ENOMEM; r = __kvm_io_bus_write(vcpu, bus, &range, val); return r < 0 ? r : 0; } EXPORT_SYMBOL_GPL(kvm_io_bus_write); /* kvm_io_bus_write_cookie - called under kvm->slots_lock */ int kvm_io_bus_write_cookie(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr, int len, const void *val, long cookie) { struct kvm_io_bus *bus; struct kvm_io_range range; range = (struct kvm_io_range) { .addr = addr, .len = len, }; bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); if (!bus) return -ENOMEM; /* First try the device referenced by cookie. */ if ((cookie >= 0) && (cookie < bus->dev_count) && (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0)) if (!kvm_iodevice_write(vcpu, bus->range[cookie].dev, addr, len, val)) return cookie; /* * cookie contained garbage; fall back to search and return the * correct cookie value. */ return __kvm_io_bus_write(vcpu, bus, &range, val); } static int __kvm_io_bus_read(struct kvm_vcpu *vcpu, struct kvm_io_bus *bus, struct kvm_io_range *range, void *val) { int idx; idx = kvm_io_bus_get_first_dev(bus, range->addr, range->len); if (idx < 0) return -EOPNOTSUPP; while (idx < bus->dev_count && kvm_io_bus_cmp(range, &bus->range[idx]) == 0) { if (!kvm_iodevice_read(vcpu, bus->range[idx].dev, range->addr, range->len, val)) return idx; idx++; } return -EOPNOTSUPP; } /* kvm_io_bus_read - called under kvm->slots_lock */ int kvm_io_bus_read(struct kvm_vcpu *vcpu, enum kvm_bus bus_idx, gpa_t addr, int len, void *val) { struct kvm_io_bus *bus; struct kvm_io_range range; int r; range = (struct kvm_io_range) { .addr = addr, .len = len, }; bus = srcu_dereference(vcpu->kvm->buses[bus_idx], &vcpu->kvm->srcu); if (!bus) return -ENOMEM; r = __kvm_io_bus_read(vcpu, bus, &range, val); return r < 0 ? r : 0; } int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len, struct kvm_io_device *dev) { int i; struct kvm_io_bus *new_bus, *bus; struct kvm_io_range range; lockdep_assert_held(&kvm->slots_lock); bus = kvm_get_bus(kvm, bus_idx); if (!bus) return -ENOMEM; /* exclude ioeventfd which is limited by maximum fd */ if (bus->dev_count - bus->ioeventfd_count > NR_IOBUS_DEVS - 1) return -ENOSPC; new_bus = kmalloc(struct_size(bus, range, bus->dev_count + 1), GFP_KERNEL_ACCOUNT); if (!new_bus) return -ENOMEM; range = (struct kvm_io_range) { .addr = addr, .len = len, .dev = dev, }; for (i = 0; i < bus->dev_count; i++) if (kvm_io_bus_cmp(&bus->range[i], &range) > 0) break; memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range)); new_bus->dev_count++; new_bus->range[i] = range; memcpy(new_bus->range + i + 1, bus->range + i, (bus->dev_count - i) * sizeof(struct kvm_io_range)); rcu_assign_pointer(kvm->buses[bus_idx], new_bus); synchronize_srcu_expedited(&kvm->srcu); kfree(bus); return 0; } int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, struct kvm_io_device *dev) { int i; struct kvm_io_bus *new_bus, *bus; lockdep_assert_held(&kvm->slots_lock); bus = kvm_get_bus(kvm, bus_idx); if (!bus) return 0; for (i = 0; i < bus->dev_count; i++) { if (bus->range[i].dev == dev) { break; } } if (i == bus->dev_count) return 0; new_bus = kmalloc(struct_size(bus, range, bus->dev_count - 1), GFP_KERNEL_ACCOUNT); if (new_bus) { memcpy(new_bus, bus, struct_size(bus, range, i)); new_bus->dev_count--; memcpy(new_bus->range + i, bus->range + i + 1, flex_array_size(new_bus, range, new_bus->dev_count - i)); } rcu_assign_pointer(kvm->buses[bus_idx], new_bus); synchronize_srcu_expedited(&kvm->srcu); /* * If NULL bus is installed, destroy the old bus, including all the * attached devices. Otherwise, destroy the caller's device only. */ if (!new_bus) { pr_err("kvm: failed to shrink bus, removing it completely\n"); kvm_io_bus_destroy(bus); return -ENOMEM; } kvm_iodevice_destructor(dev); kfree(bus); return 0; } struct kvm_io_device *kvm_io_bus_get_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr) { struct kvm_io_bus *bus; int dev_idx, srcu_idx; struct kvm_io_device *iodev = NULL; srcu_idx = srcu_read_lock(&kvm->srcu); bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu); if (!bus) goto out_unlock; dev_idx = kvm_io_bus_get_first_dev(bus, addr, 1); if (dev_idx < 0) goto out_unlock; iodev = bus->range[dev_idx].dev; out_unlock: srcu_read_unlock(&kvm->srcu, srcu_idx); return iodev; } EXPORT_SYMBOL_GPL(kvm_io_bus_get_dev); static int kvm_debugfs_open(struct inode *inode, struct file *file, int (*get)(void *, u64 *), int (*set)(void *, u64), const char *fmt) { int ret; struct kvm_stat_data *stat_data = inode->i_private; /* * The debugfs files are a reference to the kvm struct which * is still valid when kvm_destroy_vm is called. kvm_get_kvm_safe * avoids the race between open and the removal of the debugfs directory. */ if (!kvm_get_kvm_safe(stat_data->kvm)) return -ENOENT; ret = simple_attr_open(inode, file, get, kvm_stats_debugfs_mode(stat_data->desc) & 0222 ? set : NULL, fmt); if (ret) kvm_put_kvm(stat_data->kvm); return ret; } static int kvm_debugfs_release(struct inode *inode, struct file *file) { struct kvm_stat_data *stat_data = inode->i_private; simple_attr_release(inode, file); kvm_put_kvm(stat_data->kvm); return 0; } static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val) { *val = *(u64 *)((void *)(&kvm->stat) + offset); return 0; } static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset) { *(u64 *)((void *)(&kvm->stat) + offset) = 0; return 0; } static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val) { unsigned long i; struct kvm_vcpu *vcpu; *val = 0; kvm_for_each_vcpu(i, vcpu, kvm) *val += *(u64 *)((void *)(&vcpu->stat) + offset); return 0; } static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset) { unsigned long i; struct kvm_vcpu *vcpu; kvm_for_each_vcpu(i, vcpu, kvm) *(u64 *)((void *)(&vcpu->stat) + offset) = 0; return 0; } static int kvm_stat_data_get(void *data, u64 *val) { int r = -EFAULT; struct kvm_stat_data *stat_data = data; switch (stat_data->kind) { case KVM_STAT_VM: r = kvm_get_stat_per_vm(stat_data->kvm, stat_data->desc->desc.offset, val); break; case KVM_STAT_VCPU: r = kvm_get_stat_per_vcpu(stat_data->kvm, stat_data->desc->desc.offset, val); break; } return r; } static int kvm_stat_data_clear(void *data, u64 val) { int r = -EFAULT; struct kvm_stat_data *stat_data = data; if (val) return -EINVAL; switch (stat_data->kind) { case KVM_STAT_VM: r = kvm_clear_stat_per_vm(stat_data->kvm, stat_data->desc->desc.offset); break; case KVM_STAT_VCPU: r = kvm_clear_stat_per_vcpu(stat_data->kvm, stat_data->desc->desc.offset); break; } return r; } static int kvm_stat_data_open(struct inode *inode, struct file *file) { __simple_attr_check_format("%llu\n", 0ull); return kvm_debugfs_open(inode, file, kvm_stat_data_get, kvm_stat_data_clear, "%llu\n"); } static const struct file_operations stat_fops_per_vm = { .owner = THIS_MODULE, .open = kvm_stat_data_open, .release = kvm_debugfs_release, .read = simple_attr_read, .write = simple_attr_write, .llseek = no_llseek, }; static int vm_stat_get(void *_offset, u64 *val) { unsigned offset = (long)_offset; struct kvm *kvm; u64 tmp_val; *val = 0; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_get_stat_per_vm(kvm, offset, &tmp_val); *val += tmp_val; } mutex_unlock(&kvm_lock); return 0; } static int vm_stat_clear(void *_offset, u64 val) { unsigned offset = (long)_offset; struct kvm *kvm; if (val) return -EINVAL; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_clear_stat_per_vm(kvm, offset); } mutex_unlock(&kvm_lock); return 0; } DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n"); DEFINE_SIMPLE_ATTRIBUTE(vm_stat_readonly_fops, vm_stat_get, NULL, "%llu\n"); static int vcpu_stat_get(void *_offset, u64 *val) { unsigned offset = (long)_offset; struct kvm *kvm; u64 tmp_val; *val = 0; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_get_stat_per_vcpu(kvm, offset, &tmp_val); *val += tmp_val; } mutex_unlock(&kvm_lock); return 0; } static int vcpu_stat_clear(void *_offset, u64 val) { unsigned offset = (long)_offset; struct kvm *kvm; if (val) return -EINVAL; mutex_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { kvm_clear_stat_per_vcpu(kvm, offset); } mutex_unlock(&kvm_lock); return 0; } DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear, "%llu\n"); DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_readonly_fops, vcpu_stat_get, NULL, "%llu\n"); static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm) { struct kobj_uevent_env *env; unsigned long long created, active; if (!kvm_dev.this_device || !kvm) return; mutex_lock(&kvm_lock); if (type == KVM_EVENT_CREATE_VM) { kvm_createvm_count++; kvm_active_vms++; } else if (type == KVM_EVENT_DESTROY_VM) { kvm_active_vms--; } created = kvm_createvm_count; active = kvm_active_vms; mutex_unlock(&kvm_lock); env = kzalloc(sizeof(*env), GFP_KERNEL); if (!env) return; add_uevent_var(env, "CREATED=%llu", created); add_uevent_var(env, "COUNT=%llu", active); if (type == KVM_EVENT_CREATE_VM) { add_uevent_var(env, "EVENT=create"); kvm->userspace_pid = task_pid_nr(current); } else if (type == KVM_EVENT_DESTROY_VM) { add_uevent_var(env, "EVENT=destroy"); } add_uevent_var(env, "PID=%d", kvm->userspace_pid); if (!IS_ERR(kvm->debugfs_dentry)) { char *tmp, *p = kmalloc(PATH_MAX, GFP_KERNEL); if (p) { tmp = dentry_path_raw(kvm->debugfs_dentry, p, PATH_MAX); if (!IS_ERR(tmp)) add_uevent_var(env, "STATS_PATH=%s", tmp); kfree(p); } } /* no need for checks, since we are adding at most only 5 keys */ env->envp[env->envp_idx++] = NULL; kobject_uevent_env(&kvm_dev.this_device->kobj, KOBJ_CHANGE, env->envp); kfree(env); } static void kvm_init_debug(void) { const struct file_operations *fops; const struct _kvm_stats_desc *pdesc; int i; kvm_debugfs_dir = debugfs_create_dir("kvm", NULL); for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) { pdesc = &kvm_vm_stats_desc[i]; if (kvm_stats_debugfs_mode(pdesc) & 0222) fops = &vm_stat_fops; else fops = &vm_stat_readonly_fops; debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc), kvm_debugfs_dir, (void *)(long)pdesc->desc.offset, fops); } for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) { pdesc = &kvm_vcpu_stats_desc[i]; if (kvm_stats_debugfs_mode(pdesc) & 0222) fops = &vcpu_stat_fops; else fops = &vcpu_stat_readonly_fops; debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc), kvm_debugfs_dir, (void *)(long)pdesc->desc.offset, fops); } } static inline struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn) { return container_of(pn, struct kvm_vcpu, preempt_notifier); } static void kvm_sched_in(struct preempt_notifier *pn, int cpu) { struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn); WRITE_ONCE(vcpu->preempted, false); WRITE_ONCE(vcpu->ready, false); __this_cpu_write(kvm_running_vcpu, vcpu); kvm_arch_vcpu_load(vcpu, cpu); WRITE_ONCE(vcpu->scheduled_out, false); } static void kvm_sched_out(struct preempt_notifier *pn, struct task_struct *next) { struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn); WRITE_ONCE(vcpu->scheduled_out, true); if (current->on_rq && vcpu->wants_to_run) { WRITE_ONCE(vcpu->preempted, true); WRITE_ONCE(vcpu->ready, true); } kvm_arch_vcpu_put(vcpu); __this_cpu_write(kvm_running_vcpu, NULL); } /** * kvm_get_running_vcpu - get the vcpu running on the current CPU. * * We can disable preemption locally around accessing the per-CPU variable, * and use the resolved vcpu pointer after enabling preemption again, * because even if the current thread is migrated to another CPU, reading * the per-CPU value later will give us the same value as we update the * per-CPU variable in the preempt notifier handlers. */ struct kvm_vcpu *kvm_get_running_vcpu(void) { struct kvm_vcpu *vcpu; preempt_disable(); vcpu = __this_cpu_read(kvm_running_vcpu); preempt_enable(); return vcpu; } EXPORT_SYMBOL_GPL(kvm_get_running_vcpu); /** * kvm_get_running_vcpus - get the per-CPU array of currently running vcpus. */ struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void) { return &kvm_running_vcpu; } #ifdef CONFIG_GUEST_PERF_EVENTS static unsigned int kvm_guest_state(void) { struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); unsigned int state; if (!kvm_arch_pmi_in_guest(vcpu)) return 0; state = PERF_GUEST_ACTIVE; if (!kvm_arch_vcpu_in_kernel(vcpu)) state |= PERF_GUEST_USER; return state; } static unsigned long kvm_guest_get_ip(void) { struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); /* Retrieving the IP must be guarded by a call to kvm_guest_state(). */ if (WARN_ON_ONCE(!kvm_arch_pmi_in_guest(vcpu))) return 0; return kvm_arch_vcpu_get_ip(vcpu); } static struct perf_guest_info_callbacks kvm_guest_cbs = { .state = kvm_guest_state, .get_ip = kvm_guest_get_ip, .handle_intel_pt_intr = NULL, }; void kvm_register_perf_callbacks(unsigned int (*pt_intr_handler)(void)) { kvm_guest_cbs.handle_intel_pt_intr = pt_intr_handler; perf_register_guest_info_callbacks(&kvm_guest_cbs); } void kvm_unregister_perf_callbacks(void) { perf_unregister_guest_info_callbacks(&kvm_guest_cbs); } #endif int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module) { int r; int cpu; #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_ONLINE, "kvm/cpu:online", kvm_online_cpu, kvm_offline_cpu); if (r) return r; register_syscore_ops(&kvm_syscore_ops); #endif /* A kmem cache lets us meet the alignment requirements of fx_save. */ if (!vcpu_align) vcpu_align = __alignof__(struct kvm_vcpu); kvm_vcpu_cache = kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align, SLAB_ACCOUNT, offsetof(struct kvm_vcpu, arch), offsetofend(struct kvm_vcpu, stats_id) - offsetof(struct kvm_vcpu, arch), NULL); if (!kvm_vcpu_cache) { r = -ENOMEM; goto err_vcpu_cache; } for_each_possible_cpu(cpu) { if (!alloc_cpumask_var_node(&per_cpu(cpu_kick_mask, cpu), GFP_KERNEL, cpu_to_node(cpu))) { r = -ENOMEM; goto err_cpu_kick_mask; } } r = kvm_irqfd_init(); if (r) goto err_irqfd; r = kvm_async_pf_init(); if (r) goto err_async_pf; kvm_chardev_ops.owner = module; kvm_vm_fops.owner = module; kvm_vcpu_fops.owner = module; kvm_device_fops.owner = module; kvm_preempt_ops.sched_in = kvm_sched_in; kvm_preempt_ops.sched_out = kvm_sched_out; kvm_init_debug(); r = kvm_vfio_ops_init(); if (WARN_ON_ONCE(r)) goto err_vfio; kvm_gmem_init(module); /* * Registration _must_ be the very last thing done, as this exposes * /dev/kvm to userspace, i.e. all infrastructure must be setup! */ r = misc_register(&kvm_dev); if (r) { pr_err("kvm: misc device register failed\n"); goto err_register; } return 0; err_register: kvm_vfio_ops_exit(); err_vfio: kvm_async_pf_deinit(); err_async_pf: kvm_irqfd_exit(); err_irqfd: err_cpu_kick_mask: for_each_possible_cpu(cpu) free_cpumask_var(per_cpu(cpu_kick_mask, cpu)); kmem_cache_destroy(kvm_vcpu_cache); err_vcpu_cache: #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING unregister_syscore_ops(&kvm_syscore_ops); cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE); #endif return r; } EXPORT_SYMBOL_GPL(kvm_init); void kvm_exit(void) { int cpu; /* * Note, unregistering /dev/kvm doesn't strictly need to come first, * fops_get(), a.k.a. try_module_get(), prevents acquiring references * to KVM while the module is being stopped. */ misc_deregister(&kvm_dev); debugfs_remove_recursive(kvm_debugfs_dir); for_each_possible_cpu(cpu) free_cpumask_var(per_cpu(cpu_kick_mask, cpu)); kmem_cache_destroy(kvm_vcpu_cache); kvm_vfio_ops_exit(); kvm_async_pf_deinit(); #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING unregister_syscore_ops(&kvm_syscore_ops); cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE); #endif kvm_irqfd_exit(); } EXPORT_SYMBOL_GPL(kvm_exit); struct kvm_vm_worker_thread_context { struct kvm *kvm; struct task_struct *parent; struct completion init_done; kvm_vm_thread_fn_t thread_fn; uintptr_t data; int err; }; static int kvm_vm_worker_thread(void *context) { /* * The init_context is allocated on the stack of the parent thread, so * we have to locally copy anything that is needed beyond initialization */ struct kvm_vm_worker_thread_context *init_context = context; struct task_struct *parent; struct kvm *kvm = init_context->kvm; kvm_vm_thread_fn_t thread_fn = init_context->thread_fn; uintptr_t data = init_context->data; int err; err = kthread_park(current); /* kthread_park(current) is never supposed to return an error */ WARN_ON(err != 0); if (err) goto init_complete; err = cgroup_attach_task_all(init_context->parent, current); if (err) { kvm_err("%s: cgroup_attach_task_all failed with err %d\n", __func__, err); goto init_complete; } set_user_nice(current, task_nice(init_context->parent)); init_complete: init_context->err = err; complete(&init_context->init_done); init_context = NULL; if (err) goto out; /* Wait to be woken up by the spawner before proceeding. */ kthread_parkme(); if (!kthread_should_stop()) err = thread_fn(kvm, data); out: /* * Move kthread back to its original cgroup to prevent it lingering in * the cgroup of the VM process, after the latter finishes its * execution. * * kthread_stop() waits on the 'exited' completion condition which is * set in exit_mm(), via mm_release(), in do_exit(). However, the * kthread is removed from the cgroup in the cgroup_exit() which is * called after the exit_mm(). This causes the kthread_stop() to return * before the kthread actually quits the cgroup. */ rcu_read_lock(); parent = rcu_dereference(current->real_parent); get_task_struct(parent); rcu_read_unlock(); cgroup_attach_task_all(parent, current); put_task_struct(parent); return err; } int kvm_vm_create_worker_thread(struct kvm *kvm, kvm_vm_thread_fn_t thread_fn, uintptr_t data, const char *name, struct task_struct **thread_ptr) { struct kvm_vm_worker_thread_context init_context = {}; struct task_struct *thread; *thread_ptr = NULL; init_context.kvm = kvm; init_context.parent = current; init_context.thread_fn = thread_fn; init_context.data = data; init_completion(&init_context.init_done); thread = kthread_run(kvm_vm_worker_thread, &init_context, "%s-%d", name, task_pid_nr(current)); if (IS_ERR(thread)) return PTR_ERR(thread); /* kthread_run is never supposed to return NULL */ WARN_ON(thread == NULL); wait_for_completion(&init_context.init_done); if (!init_context.err) *thread_ptr = thread; return init_context.err; }
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