Contributors: 47
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Gleb Natapov |
873 |
25.56% |
6 |
6.38% |
| Wanpeng Li |
809 |
23.69% |
14 |
14.89% |
| Glauber de Oliveira Costa |
253 |
7.41% |
1 |
1.06% |
| Marcelo Tosatti |
183 |
5.36% |
5 |
5.32% |
| Thomas Gleixner |
158 |
4.63% |
5 |
5.32% |
| Michael S. Tsirkin |
145 |
4.25% |
3 |
3.19% |
| Paolo Bonzini |
118 |
3.46% |
3 |
3.19% |
| Vitaly Kuznetsov |
115 |
3.37% |
4 |
4.26% |
| Srivatsa Vaddagiri |
112 |
3.28% |
1 |
1.06% |
| Brijesh Singh |
110 |
3.22% |
1 |
1.06% |
| Peter Zijlstra |
74 |
2.17% |
4 |
4.26% |
| Duan Zhenzhong |
72 |
2.11% |
3 |
3.19% |
| Waiman Long |
52 |
1.52% |
4 |
4.26% |
| Andrew Lutomirski |
46 |
1.35% |
2 |
2.13% |
| Sebastian Andrzej Siewior |
46 |
1.35% |
1 |
1.06% |
| Juergen Gross |
42 |
1.23% |
4 |
4.26% |
| Prarit Bhargava |
28 |
0.82% |
1 |
1.06% |
| Sean Christopherson |
27 |
0.79% |
1 |
1.06% |
| Christoph Lameter |
24 |
0.70% |
1 |
1.06% |
| Rik Van Riel |
17 |
0.50% |
1 |
1.06% |
| Joao Martins |
14 |
0.41% |
1 |
1.06% |
| Thadeu Lima de Souza Cascardo |
11 |
0.32% |
1 |
1.06% |
| Chris Wright |
10 |
0.29% |
1 |
1.06% |
| Ulrich Obergfell |
7 |
0.20% |
2 |
2.13% |
| Shuah Khan |
6 |
0.18% |
1 |
1.06% |
| Radim Krčmář |
6 |
0.18% |
1 |
1.06% |
| Alok N Kataria |
5 |
0.15% |
1 |
1.06% |
| Raghavendra K T |
5 |
0.15% |
2 |
2.13% |
| Boqun Feng |
5 |
0.15% |
1 |
1.06% |
| Pavel Tatashin |
5 |
0.15% |
1 |
1.06% |
| Dave Hansen |
4 |
0.12% |
1 |
1.06% |
| Borislav Petkov |
4 |
0.12% |
1 |
1.06% |
| Yi Wang |
3 |
0.09% |
1 |
1.06% |
| Florian Westphal |
3 |
0.09% |
1 |
1.06% |
| Frédéric Weisbecker |
3 |
0.09% |
1 |
1.06% |
| Jason (Hui) Wang |
3 |
0.09% |
1 |
1.06% |
| Linus Torvalds |
3 |
0.09% |
1 |
1.06% |
| Masami Hiramatsu |
2 |
0.06% |
1 |
1.06% |
| Dou Liyang |
2 |
0.06% |
1 |
1.06% |
| Li Zhong |
2 |
0.06% |
1 |
1.06% |
| Ingo Molnar |
2 |
0.06% |
1 |
1.06% |
| Nicholas Krause |
1 |
0.03% |
1 |
1.06% |
| Haiwei Li |
1 |
0.03% |
1 |
1.06% |
| Andi Kleen |
1 |
0.03% |
1 |
1.06% |
| Davidlohr Bueso A |
1 |
0.03% |
1 |
1.06% |
| Paul Gortmaker |
1 |
0.03% |
1 |
1.06% |
| Josh Poimboeuf |
1 |
0.03% |
1 |
1.06% |
| Total |
3415 |
|
94 |
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* KVM paravirt_ops implementation
*
* Copyright (C) 2007, Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
* Copyright IBM Corporation, 2007
* Authors: Anthony Liguori <aliguori@us.ibm.com>
*/
#define pr_fmt(fmt) "kvm-guest: " fmt
#include <linux/context_tracking.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/kvm_para.h>
#include <linux/cpu.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/hardirq.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/hash.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/kprobes.h>
#include <linux/nmi.h>
#include <linux/swait.h>
#include <asm/timer.h>
#include <asm/cpu.h>
#include <asm/traps.h>
#include <asm/desc.h>
#include <asm/tlbflush.h>
#include <asm/apic.h>
#include <asm/apicdef.h>
#include <asm/hypervisor.h>
#include <asm/tlb.h>
#include <asm/cpuidle_haltpoll.h>
DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled);
static int kvmapf = 1;
static int __init parse_no_kvmapf(char *arg)
{
kvmapf = 0;
return 0;
}
early_param("no-kvmapf", parse_no_kvmapf);
static int steal_acc = 1;
static int __init parse_no_stealacc(char *arg)
{
steal_acc = 0;
return 0;
}
early_param("no-steal-acc", parse_no_stealacc);
static DEFINE_PER_CPU_DECRYPTED(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64);
DEFINE_PER_CPU_DECRYPTED(struct kvm_steal_time, steal_time) __aligned(64) __visible;
static int has_steal_clock = 0;
/*
* No need for any "IO delay" on KVM
*/
static void kvm_io_delay(void)
{
}
#define KVM_TASK_SLEEP_HASHBITS 8
#define KVM_TASK_SLEEP_HASHSIZE (1<<KVM_TASK_SLEEP_HASHBITS)
struct kvm_task_sleep_node {
struct hlist_node link;
struct swait_queue_head wq;
u32 token;
int cpu;
};
static struct kvm_task_sleep_head {
raw_spinlock_t lock;
struct hlist_head list;
} async_pf_sleepers[KVM_TASK_SLEEP_HASHSIZE];
static struct kvm_task_sleep_node *_find_apf_task(struct kvm_task_sleep_head *b,
u32 token)
{
struct hlist_node *p;
hlist_for_each(p, &b->list) {
struct kvm_task_sleep_node *n =
hlist_entry(p, typeof(*n), link);
if (n->token == token)
return n;
}
return NULL;
}
static bool kvm_async_pf_queue_task(u32 token, struct kvm_task_sleep_node *n)
{
u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
struct kvm_task_sleep_node *e;
raw_spin_lock(&b->lock);
e = _find_apf_task(b, token);
if (e) {
/* dummy entry exist -> wake up was delivered ahead of PF */
hlist_del(&e->link);
raw_spin_unlock(&b->lock);
kfree(e);
return false;
}
n->token = token;
n->cpu = smp_processor_id();
init_swait_queue_head(&n->wq);
hlist_add_head(&n->link, &b->list);
raw_spin_unlock(&b->lock);
return true;
}
/*
* kvm_async_pf_task_wait_schedule - Wait for pagefault to be handled
* @token: Token to identify the sleep node entry
*
* Invoked from the async pagefault handling code or from the VM exit page
* fault handler. In both cases RCU is watching.
*/
void kvm_async_pf_task_wait_schedule(u32 token)
{
struct kvm_task_sleep_node n;
DECLARE_SWAITQUEUE(wait);
lockdep_assert_irqs_disabled();
if (!kvm_async_pf_queue_task(token, &n))
return;
for (;;) {
prepare_to_swait_exclusive(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
if (hlist_unhashed(&n.link))
break;
local_irq_enable();
schedule();
local_irq_disable();
}
finish_swait(&n.wq, &wait);
}
EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait_schedule);
static void apf_task_wake_one(struct kvm_task_sleep_node *n)
{
hlist_del_init(&n->link);
if (swq_has_sleeper(&n->wq))
swake_up_one(&n->wq);
}
static void apf_task_wake_all(void)
{
int i;
for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++) {
struct kvm_task_sleep_head *b = &async_pf_sleepers[i];
struct kvm_task_sleep_node *n;
struct hlist_node *p, *next;
raw_spin_lock(&b->lock);
hlist_for_each_safe(p, next, &b->list) {
n = hlist_entry(p, typeof(*n), link);
if (n->cpu == smp_processor_id())
apf_task_wake_one(n);
}
raw_spin_unlock(&b->lock);
}
}
void kvm_async_pf_task_wake(u32 token)
{
u32 key = hash_32(token, KVM_TASK_SLEEP_HASHBITS);
struct kvm_task_sleep_head *b = &async_pf_sleepers[key];
struct kvm_task_sleep_node *n;
if (token == ~0) {
apf_task_wake_all();
return;
}
again:
raw_spin_lock(&b->lock);
n = _find_apf_task(b, token);
if (!n) {
/*
* async PF was not yet handled.
* Add dummy entry for the token.
*/
n = kzalloc(sizeof(*n), GFP_ATOMIC);
if (!n) {
/*
* Allocation failed! Busy wait while other cpu
* handles async PF.
*/
raw_spin_unlock(&b->lock);
cpu_relax();
goto again;
}
n->token = token;
n->cpu = smp_processor_id();
init_swait_queue_head(&n->wq);
hlist_add_head(&n->link, &b->list);
} else {
apf_task_wake_one(n);
}
raw_spin_unlock(&b->lock);
return;
}
EXPORT_SYMBOL_GPL(kvm_async_pf_task_wake);
noinstr u32 kvm_read_and_reset_apf_flags(void)
{
u32 flags = 0;
if (__this_cpu_read(apf_reason.enabled)) {
flags = __this_cpu_read(apf_reason.flags);
__this_cpu_write(apf_reason.flags, 0);
}
return flags;
}
EXPORT_SYMBOL_GPL(kvm_read_and_reset_apf_flags);
noinstr bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token)
{
u32 flags = kvm_read_and_reset_apf_flags();
irqentry_state_t state;
if (!flags)
return false;
state = irqentry_enter(regs);
instrumentation_begin();
/*
* If the host managed to inject an async #PF into an interrupt
* disabled region, then die hard as this is not going to end well
* and the host side is seriously broken.
*/
if (unlikely(!(regs->flags & X86_EFLAGS_IF)))
panic("Host injected async #PF in interrupt disabled region\n");
if (flags & KVM_PV_REASON_PAGE_NOT_PRESENT) {
if (unlikely(!(user_mode(regs))))
panic("Host injected async #PF in kernel mode\n");
/* Page is swapped out by the host. */
kvm_async_pf_task_wait_schedule(token);
} else {
WARN_ONCE(1, "Unexpected async PF flags: %x\n", flags);
}
instrumentation_end();
irqentry_exit(regs, state);
return true;
}
DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_asyncpf_interrupt)
{
struct pt_regs *old_regs = set_irq_regs(regs);
u32 token;
ack_APIC_irq();
inc_irq_stat(irq_hv_callback_count);
if (__this_cpu_read(apf_reason.enabled)) {
token = __this_cpu_read(apf_reason.token);
kvm_async_pf_task_wake(token);
__this_cpu_write(apf_reason.token, 0);
wrmsrl(MSR_KVM_ASYNC_PF_ACK, 1);
}
set_irq_regs(old_regs);
}
static void __init paravirt_ops_setup(void)
{
pv_info.name = "KVM";
if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY))
pv_ops.cpu.io_delay = kvm_io_delay;
#ifdef CONFIG_X86_IO_APIC
no_timer_check = 1;
#endif
}
static void kvm_register_steal_time(void)
{
int cpu = smp_processor_id();
struct kvm_steal_time *st = &per_cpu(steal_time, cpu);
if (!has_steal_clock)
return;
wrmsrl(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED));
pr_info("stealtime: cpu %d, msr %llx\n", cpu,
(unsigned long long) slow_virt_to_phys(st));
}
static DEFINE_PER_CPU_DECRYPTED(unsigned long, kvm_apic_eoi) = KVM_PV_EOI_DISABLED;
static notrace void kvm_guest_apic_eoi_write(u32 reg, u32 val)
{
/**
* This relies on __test_and_clear_bit to modify the memory
* in a way that is atomic with respect to the local CPU.
* The hypervisor only accesses this memory from the local CPU so
* there's no need for lock or memory barriers.
* An optimization barrier is implied in apic write.
*/
if (__test_and_clear_bit(KVM_PV_EOI_BIT, this_cpu_ptr(&kvm_apic_eoi)))
return;
apic->native_eoi_write(APIC_EOI, APIC_EOI_ACK);
}
static void kvm_guest_cpu_init(void)
{
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) {
u64 pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
WARN_ON_ONCE(!static_branch_likely(&kvm_async_pf_enabled));
pa = slow_virt_to_phys(this_cpu_ptr(&apf_reason));
pa |= KVM_ASYNC_PF_ENABLED | KVM_ASYNC_PF_DELIVERY_AS_INT;
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_VMEXIT))
pa |= KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT;
wrmsrl(MSR_KVM_ASYNC_PF_INT, HYPERVISOR_CALLBACK_VECTOR);
wrmsrl(MSR_KVM_ASYNC_PF_EN, pa);
__this_cpu_write(apf_reason.enabled, 1);
pr_info("KVM setup async PF for cpu %d\n", smp_processor_id());
}
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) {
unsigned long pa;
/* Size alignment is implied but just to make it explicit. */
BUILD_BUG_ON(__alignof__(kvm_apic_eoi) < 4);
__this_cpu_write(kvm_apic_eoi, 0);
pa = slow_virt_to_phys(this_cpu_ptr(&kvm_apic_eoi))
| KVM_MSR_ENABLED;
wrmsrl(MSR_KVM_PV_EOI_EN, pa);
}
if (has_steal_clock)
kvm_register_steal_time();
}
static void kvm_pv_disable_apf(void)
{
if (!__this_cpu_read(apf_reason.enabled))
return;
wrmsrl(MSR_KVM_ASYNC_PF_EN, 0);
__this_cpu_write(apf_reason.enabled, 0);
pr_info("Unregister pv shared memory for cpu %d\n", smp_processor_id());
}
static void kvm_pv_guest_cpu_reboot(void *unused)
{
/*
* We disable PV EOI before we load a new kernel by kexec,
* since MSR_KVM_PV_EOI_EN stores a pointer into old kernel's memory.
* New kernel can re-enable when it boots.
*/
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
wrmsrl(MSR_KVM_PV_EOI_EN, 0);
kvm_pv_disable_apf();
kvm_disable_steal_time();
}
static int kvm_pv_reboot_notify(struct notifier_block *nb,
unsigned long code, void *unused)
{
if (code == SYS_RESTART)
on_each_cpu(kvm_pv_guest_cpu_reboot, NULL, 1);
return NOTIFY_DONE;
}
static struct notifier_block kvm_pv_reboot_nb = {
.notifier_call = kvm_pv_reboot_notify,
};
static u64 kvm_steal_clock(int cpu)
{
u64 steal;
struct kvm_steal_time *src;
int version;
src = &per_cpu(steal_time, cpu);
do {
version = src->version;
virt_rmb();
steal = src->steal;
virt_rmb();
} while ((version & 1) || (version != src->version));
return steal;
}
void kvm_disable_steal_time(void)
{
if (!has_steal_clock)
return;
wrmsr(MSR_KVM_STEAL_TIME, 0, 0);
}
static inline void __set_percpu_decrypted(void *ptr, unsigned long size)
{
early_set_memory_decrypted((unsigned long) ptr, size);
}
/*
* Iterate through all possible CPUs and map the memory region pointed
* by apf_reason, steal_time and kvm_apic_eoi as decrypted at once.
*
* Note: we iterate through all possible CPUs to ensure that CPUs
* hotplugged will have their per-cpu variable already mapped as
* decrypted.
*/
static void __init sev_map_percpu_data(void)
{
int cpu;
if (!sev_active())
return;
for_each_possible_cpu(cpu) {
__set_percpu_decrypted(&per_cpu(apf_reason, cpu), sizeof(apf_reason));
__set_percpu_decrypted(&per_cpu(steal_time, cpu), sizeof(steal_time));
__set_percpu_decrypted(&per_cpu(kvm_apic_eoi, cpu), sizeof(kvm_apic_eoi));
}
}
static bool pv_tlb_flush_supported(void)
{
return (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME));
}
static DEFINE_PER_CPU(cpumask_var_t, __pv_cpu_mask);
#ifdef CONFIG_SMP
static bool pv_ipi_supported(void)
{
return kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI);
}
static bool pv_sched_yield_supported(void)
{
return (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME));
}
#define KVM_IPI_CLUSTER_SIZE (2 * BITS_PER_LONG)
static void __send_ipi_mask(const struct cpumask *mask, int vector)
{
unsigned long flags;
int cpu, apic_id, icr;
int min = 0, max = 0;
#ifdef CONFIG_X86_64
__uint128_t ipi_bitmap = 0;
#else
u64 ipi_bitmap = 0;
#endif
long ret;
if (cpumask_empty(mask))
return;
local_irq_save(flags);
switch (vector) {
default:
icr = APIC_DM_FIXED | vector;
break;
case NMI_VECTOR:
icr = APIC_DM_NMI;
break;
}
for_each_cpu(cpu, mask) {
apic_id = per_cpu(x86_cpu_to_apicid, cpu);
if (!ipi_bitmap) {
min = max = apic_id;
} else if (apic_id < min && max - apic_id < KVM_IPI_CLUSTER_SIZE) {
ipi_bitmap <<= min - apic_id;
min = apic_id;
} else if (apic_id < min + KVM_IPI_CLUSTER_SIZE) {
max = apic_id < max ? max : apic_id;
} else {
ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
(unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
WARN_ONCE(ret < 0, "kvm-guest: failed to send PV IPI: %ld",
ret);
min = max = apic_id;
ipi_bitmap = 0;
}
__set_bit(apic_id - min, (unsigned long *)&ipi_bitmap);
}
if (ipi_bitmap) {
ret = kvm_hypercall4(KVM_HC_SEND_IPI, (unsigned long)ipi_bitmap,
(unsigned long)(ipi_bitmap >> BITS_PER_LONG), min, icr);
WARN_ONCE(ret < 0, "kvm-guest: failed to send PV IPI: %ld",
ret);
}
local_irq_restore(flags);
}
static void kvm_send_ipi_mask(const struct cpumask *mask, int vector)
{
__send_ipi_mask(mask, vector);
}
static void kvm_send_ipi_mask_allbutself(const struct cpumask *mask, int vector)
{
unsigned int this_cpu = smp_processor_id();
struct cpumask *new_mask = this_cpu_cpumask_var_ptr(__pv_cpu_mask);
const struct cpumask *local_mask;
cpumask_copy(new_mask, mask);
cpumask_clear_cpu(this_cpu, new_mask);
local_mask = new_mask;
__send_ipi_mask(local_mask, vector);
}
/*
* Set the IPI entry points
*/
static void kvm_setup_pv_ipi(void)
{
apic->send_IPI_mask = kvm_send_ipi_mask;
apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself;
pr_info("setup PV IPIs\n");
}
static void kvm_smp_send_call_func_ipi(const struct cpumask *mask)
{
int cpu;
native_send_call_func_ipi(mask);
/* Make sure other vCPUs get a chance to run if they need to. */
for_each_cpu(cpu, mask) {
if (vcpu_is_preempted(cpu)) {
kvm_hypercall1(KVM_HC_SCHED_YIELD, per_cpu(x86_cpu_to_apicid, cpu));
break;
}
}
}
static void __init kvm_smp_prepare_boot_cpu(void)
{
/*
* Map the per-cpu variables as decrypted before kvm_guest_cpu_init()
* shares the guest physical address with the hypervisor.
*/
sev_map_percpu_data();
kvm_guest_cpu_init();
native_smp_prepare_boot_cpu();
kvm_spinlock_init();
}
static void kvm_guest_cpu_offline(void)
{
kvm_disable_steal_time();
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
wrmsrl(MSR_KVM_PV_EOI_EN, 0);
kvm_pv_disable_apf();
apf_task_wake_all();
}
static int kvm_cpu_online(unsigned int cpu)
{
local_irq_disable();
kvm_guest_cpu_init();
local_irq_enable();
return 0;
}
static int kvm_cpu_down_prepare(unsigned int cpu)
{
local_irq_disable();
kvm_guest_cpu_offline();
local_irq_enable();
return 0;
}
#endif
static void kvm_flush_tlb_others(const struct cpumask *cpumask,
const struct flush_tlb_info *info)
{
u8 state;
int cpu;
struct kvm_steal_time *src;
struct cpumask *flushmask = this_cpu_cpumask_var_ptr(__pv_cpu_mask);
cpumask_copy(flushmask, cpumask);
/*
* We have to call flush only on online vCPUs. And
* queue flush_on_enter for pre-empted vCPUs
*/
for_each_cpu(cpu, flushmask) {
src = &per_cpu(steal_time, cpu);
state = READ_ONCE(src->preempted);
if ((state & KVM_VCPU_PREEMPTED)) {
if (try_cmpxchg(&src->preempted, &state,
state | KVM_VCPU_FLUSH_TLB))
__cpumask_clear_cpu(cpu, flushmask);
}
}
native_flush_tlb_others(flushmask, info);
}
static void __init kvm_guest_init(void)
{
int i;
paravirt_ops_setup();
register_reboot_notifier(&kvm_pv_reboot_nb);
for (i = 0; i < KVM_TASK_SLEEP_HASHSIZE; i++)
raw_spin_lock_init(&async_pf_sleepers[i].lock);
if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
has_steal_clock = 1;
pv_ops.time.steal_clock = kvm_steal_clock;
}
if (pv_tlb_flush_supported()) {
pv_ops.mmu.flush_tlb_others = kvm_flush_tlb_others;
pv_ops.mmu.tlb_remove_table = tlb_remove_table;
pr_info("KVM setup pv remote TLB flush\n");
}
if (kvm_para_has_feature(KVM_FEATURE_PV_EOI))
apic_set_eoi_write(kvm_guest_apic_eoi_write);
if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_INT) && kvmapf) {
static_branch_enable(&kvm_async_pf_enabled);
alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_kvm_asyncpf_interrupt);
}
#ifdef CONFIG_SMP
smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu;
if (pv_sched_yield_supported()) {
smp_ops.send_call_func_ipi = kvm_smp_send_call_func_ipi;
pr_info("setup PV sched yield\n");
}
if (cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/kvm:online",
kvm_cpu_online, kvm_cpu_down_prepare) < 0)
pr_err("failed to install cpu hotplug callbacks\n");
#else
sev_map_percpu_data();
kvm_guest_cpu_init();
#endif
/*
* Hard lockup detection is enabled by default. Disable it, as guests
* can get false positives too easily, for example if the host is
* overcommitted.
*/
hardlockup_detector_disable();
}
static noinline uint32_t __kvm_cpuid_base(void)
{
if (boot_cpu_data.cpuid_level < 0)
return 0; /* So we don't blow up on old processors */
if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0);
return 0;
}
static inline uint32_t kvm_cpuid_base(void)
{
static int kvm_cpuid_base = -1;
if (kvm_cpuid_base == -1)
kvm_cpuid_base = __kvm_cpuid_base();
return kvm_cpuid_base;
}
bool kvm_para_available(void)
{
return kvm_cpuid_base() != 0;
}
EXPORT_SYMBOL_GPL(kvm_para_available);
unsigned int kvm_arch_para_features(void)
{
return cpuid_eax(kvm_cpuid_base() | KVM_CPUID_FEATURES);
}
unsigned int kvm_arch_para_hints(void)
{
return cpuid_edx(kvm_cpuid_base() | KVM_CPUID_FEATURES);
}
EXPORT_SYMBOL_GPL(kvm_arch_para_hints);
static uint32_t __init kvm_detect(void)
{
return kvm_cpuid_base();
}
static void __init kvm_apic_init(void)
{
#if defined(CONFIG_SMP)
if (pv_ipi_supported())
kvm_setup_pv_ipi();
#endif
}
static void __init kvm_init_platform(void)
{
kvmclock_init();
x86_platform.apic_post_init = kvm_apic_init;
}
const __initconst struct hypervisor_x86 x86_hyper_kvm = {
.name = "KVM",
.detect = kvm_detect,
.type = X86_HYPER_KVM,
.init.guest_late_init = kvm_guest_init,
.init.x2apic_available = kvm_para_available,
.init.init_platform = kvm_init_platform,
};
static __init int activate_jump_labels(void)
{
if (has_steal_clock) {
static_key_slow_inc(¶virt_steal_enabled);
if (steal_acc)
static_key_slow_inc(¶virt_steal_rq_enabled);
}
return 0;
}
arch_initcall(activate_jump_labels);
static __init int kvm_alloc_cpumask(void)
{
int cpu;
bool alloc = false;
if (!kvm_para_available() || nopv)
return 0;
if (pv_tlb_flush_supported())
alloc = true;
#if defined(CONFIG_SMP)
if (pv_ipi_supported())
alloc = true;
#endif
if (alloc)
for_each_possible_cpu(cpu) {
zalloc_cpumask_var_node(per_cpu_ptr(&__pv_cpu_mask, cpu),
GFP_KERNEL, cpu_to_node(cpu));
}
return 0;
}
arch_initcall(kvm_alloc_cpumask);
#ifdef CONFIG_PARAVIRT_SPINLOCKS
/* Kick a cpu by its apicid. Used to wake up a halted vcpu */
static void kvm_kick_cpu(int cpu)
{
int apicid;
unsigned long flags = 0;
apicid = per_cpu(x86_cpu_to_apicid, cpu);
kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid);
}
#include <asm/qspinlock.h>
static void kvm_wait(u8 *ptr, u8 val)
{
unsigned long flags;
if (in_nmi())
return;
local_irq_save(flags);
if (READ_ONCE(*ptr) != val)
goto out;
/*
* halt until it's our turn and kicked. Note that we do safe halt
* for irq enabled case to avoid hang when lock info is overwritten
* in irq spinlock slowpath and no spurious interrupt occur to save us.
*/
if (arch_irqs_disabled_flags(flags))
halt();
else
safe_halt();
out:
local_irq_restore(flags);
}
#ifdef CONFIG_X86_32
__visible bool __kvm_vcpu_is_preempted(long cpu)
{
struct kvm_steal_time *src = &per_cpu(steal_time, cpu);
return !!(src->preempted & KVM_VCPU_PREEMPTED);
}
PV_CALLEE_SAVE_REGS_THUNK(__kvm_vcpu_is_preempted);
#else
#include <asm/asm-offsets.h>
extern bool __raw_callee_save___kvm_vcpu_is_preempted(long);
/*
* Hand-optimize version for x86-64 to avoid 8 64-bit register saving and
* restoring to/from the stack.
*/
asm(
".pushsection .text;"
".global __raw_callee_save___kvm_vcpu_is_preempted;"
".type __raw_callee_save___kvm_vcpu_is_preempted, @function;"
"__raw_callee_save___kvm_vcpu_is_preempted:"
"movq __per_cpu_offset(,%rdi,8), %rax;"
"cmpb $0, " __stringify(KVM_STEAL_TIME_preempted) "+steal_time(%rax);"
"setne %al;"
"ret;"
".size __raw_callee_save___kvm_vcpu_is_preempted, .-__raw_callee_save___kvm_vcpu_is_preempted;"
".popsection");
#endif
/*
* Setup pv_lock_ops to exploit KVM_FEATURE_PV_UNHALT if present.
*/
void __init kvm_spinlock_init(void)
{
/*
* In case host doesn't support KVM_FEATURE_PV_UNHALT there is still an
* advantage of keeping virt_spin_lock_key enabled: virt_spin_lock() is
* preferred over native qspinlock when vCPU is preempted.
*/
if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) {
pr_info("PV spinlocks disabled, no host support\n");
return;
}
/*
* Disable PV spinlocks and use native qspinlock when dedicated pCPUs
* are available.
*/
if (kvm_para_has_hint(KVM_HINTS_REALTIME)) {
pr_info("PV spinlocks disabled with KVM_HINTS_REALTIME hints\n");
goto out;
}
if (num_possible_cpus() == 1) {
pr_info("PV spinlocks disabled, single CPU\n");
goto out;
}
if (nopvspin) {
pr_info("PV spinlocks disabled, forced by \"nopvspin\" parameter\n");
goto out;
}
pr_info("PV spinlocks enabled\n");
__pv_init_lock_hash();
pv_ops.lock.queued_spin_lock_slowpath = __pv_queued_spin_lock_slowpath;
pv_ops.lock.queued_spin_unlock =
PV_CALLEE_SAVE(__pv_queued_spin_unlock);
pv_ops.lock.wait = kvm_wait;
pv_ops.lock.kick = kvm_kick_cpu;
if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) {
pv_ops.lock.vcpu_is_preempted =
PV_CALLEE_SAVE(__kvm_vcpu_is_preempted);
}
/*
* When PV spinlock is enabled which is preferred over
* virt_spin_lock(), virt_spin_lock_key's value is meaningless.
* Just disable it anyway.
*/
out:
static_branch_disable(&virt_spin_lock_key);
}
#endif /* CONFIG_PARAVIRT_SPINLOCKS */
#ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL
static void kvm_disable_host_haltpoll(void *i)
{
wrmsrl(MSR_KVM_POLL_CONTROL, 0);
}
static void kvm_enable_host_haltpoll(void *i)
{
wrmsrl(MSR_KVM_POLL_CONTROL, 1);
}
void arch_haltpoll_enable(unsigned int cpu)
{
if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) {
pr_err_once("host does not support poll control\n");
pr_err_once("host upgrade recommended\n");
return;
}
/* Enable guest halt poll disables host halt poll */
smp_call_function_single(cpu, kvm_disable_host_haltpoll, NULL, 1);
}
EXPORT_SYMBOL_GPL(arch_haltpoll_enable);
void arch_haltpoll_disable(unsigned int cpu)
{
if (!kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL))
return;
/* Enable guest halt poll disables host halt poll */
smp_call_function_single(cpu, kvm_enable_host_haltpoll, NULL, 1);
}
EXPORT_SYMBOL_GPL(arch_haltpoll_disable);
#endif