// SPDX-License-Identifier: GPL-2.0 #include <linux/acpi.h> #include <linux/cpu.h> #include <linux/kexec.h> #include <linux/memblock.h> #include <linux/virtio_anchor.h> #include <xen/features.h> #include <xen/events.h> #include <xen/hvm.h> #include <xen/interface/hvm/hvm_op.h> #include <xen/interface/memory.h> #include <asm/apic.h> #include <asm/cpu.h> #include <asm/smp.h> #include <asm/io_apic.h> #include <asm/reboot.h> #include <asm/setup.h> #include <asm/idtentry.h> #include <asm/hypervisor.h> #include <asm/e820/api.h> #include <asm/early_ioremap.h> #include <asm/xen/cpuid.h> #include <asm/xen/hypervisor.h> #include <asm/xen/page.h> #include "xen-ops.h" #include "mmu.h" #include "smp.h" static unsigned long shared_info_pfn; __ro_after_init bool xen_percpu_upcall; EXPORT_SYMBOL_GPL(xen_percpu_upcall); void xen_hvm_init_shared_info(void) { struct xen_add_to_physmap xatp; xatp.domid = DOMID_SELF; xatp.idx = 0; xatp.space = XENMAPSPACE_shared_info; xatp.gpfn = shared_info_pfn; if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) BUG(); } static void __init reserve_shared_info(void) { u64 pa; /* * Search for a free page starting at 4kB physical address. * Low memory is preferred to avoid an EPT large page split up * by the mapping. * Starting below X86_RESERVE_LOW (usually 64kB) is fine as * the BIOS used for HVM guests is well behaved and won't * clobber memory other than the first 4kB. */ for (pa = PAGE_SIZE; !e820__mapped_all(pa, pa + PAGE_SIZE, E820_TYPE_RAM) || memblock_is_reserved(pa); pa += PAGE_SIZE) ; shared_info_pfn = PHYS_PFN(pa); memblock_reserve(pa, PAGE_SIZE); HYPERVISOR_shared_info = early_memremap(pa, PAGE_SIZE); } static void __init xen_hvm_init_mem_mapping(void) { early_memunmap(HYPERVISOR_shared_info, PAGE_SIZE); HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn)); /* * The virtual address of the shared_info page has changed, so * the vcpu_info pointer for VCPU 0 is now stale. * * The prepare_boot_cpu callback will re-initialize it via * xen_vcpu_setup, but we can't rely on that to be called for * old Xen versions (xen_have_vector_callback == 0). * * It is, in any case, bad to have a stale vcpu_info pointer * so reset it now. */ xen_vcpu_info_reset(0); } static void __init init_hvm_pv_info(void) { int major, minor; uint32_t eax, ebx, ecx, edx, base; base = xen_cpuid_base(); eax = cpuid_eax(base + 1); major = eax >> 16; minor = eax & 0xffff; printk(KERN_INFO "Xen version %d.%d.\n", major, minor); xen_domain_type = XEN_HVM_DOMAIN; /* PVH set up hypercall page in xen_prepare_pvh(). */ if (xen_pvh_domain()) pv_info.name = "Xen PVH"; else { u64 pfn; uint32_t msr; pv_info.name = "Xen HVM"; msr = cpuid_ebx(base + 2); pfn = __pa(hypercall_page); wrmsr_safe(msr, (u32)pfn, (u32)(pfn >> 32)); } xen_setup_features(); cpuid(base + 4, &eax, &ebx, &ecx, &edx); if (eax & XEN_HVM_CPUID_VCPU_ID_PRESENT) this_cpu_write(xen_vcpu_id, ebx); else this_cpu_write(xen_vcpu_id, smp_processor_id()); } DEFINE_IDTENTRY_SYSVEC(sysvec_xen_hvm_callback) { struct pt_regs *old_regs = set_irq_regs(regs); if (xen_percpu_upcall) apic_eoi(); inc_irq_stat(irq_hv_callback_count); xen_evtchn_do_upcall(); set_irq_regs(old_regs); } #ifdef CONFIG_KEXEC_CORE static void xen_hvm_shutdown(void) { native_machine_shutdown(); if (kexec_in_progress) xen_reboot(SHUTDOWN_soft_reset); } static void xen_hvm_crash_shutdown(struct pt_regs *regs) { native_machine_crash_shutdown(regs); xen_reboot(SHUTDOWN_soft_reset); } #endif static int xen_cpu_up_prepare_hvm(unsigned int cpu) { int rc = 0; /* * If a CPU was offlined earlier and offlining timed out then the * lock mechanism is still initialized. Uninit it unconditionally * as it's safe to call even if already uninited. Interrupts and * timer have already been handled in xen_cpu_dead_hvm(). */ xen_uninit_lock_cpu(cpu); if (cpu_acpi_id(cpu) != U32_MAX) per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu); else per_cpu(xen_vcpu_id, cpu) = cpu; xen_vcpu_setup(cpu); if (!xen_have_vector_callback) return 0; if (xen_percpu_upcall) { rc = xen_set_upcall_vector(cpu); if (rc) { WARN(1, "HVMOP_set_evtchn_upcall_vector" " for CPU %d failed: %d\n", cpu, rc); return rc; } } if (xen_feature(XENFEAT_hvm_safe_pvclock)) xen_setup_timer(cpu); rc = xen_smp_intr_init(cpu); if (rc) { WARN(1, "xen_smp_intr_init() for CPU %d failed: %d\n", cpu, rc); } return rc; } static int xen_cpu_dead_hvm(unsigned int cpu) { xen_smp_intr_free(cpu); if (xen_have_vector_callback && xen_feature(XENFEAT_hvm_safe_pvclock)) xen_teardown_timer(cpu); return 0; } static void __init xen_hvm_guest_init(void) { if (xen_pv_domain()) return; if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT)) virtio_set_mem_acc_cb(xen_virtio_restricted_mem_acc); init_hvm_pv_info(); reserve_shared_info(); xen_hvm_init_shared_info(); /* * xen_vcpu is a pointer to the vcpu_info struct in the shared_info * page, we use it in the event channel upcall and in some pvclock * related functions. */ xen_vcpu_info_reset(0); xen_panic_handler_init(); xen_hvm_smp_init(); WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm)); xen_unplug_emulated_devices(); x86_init.irqs.intr_init = xen_init_IRQ; xen_hvm_init_time_ops(); xen_hvm_init_mmu_ops(); #ifdef CONFIG_KEXEC_CORE machine_ops.shutdown = xen_hvm_shutdown; machine_ops.crash_shutdown = xen_hvm_crash_shutdown; #endif } static __init int xen_parse_nopv(char *arg) { pr_notice("\"xen_nopv\" is deprecated, please use \"nopv\" instead\n"); if (xen_cpuid_base()) nopv = true; return 0; } early_param("xen_nopv", xen_parse_nopv); static __init int xen_parse_no_vector_callback(char *arg) { xen_have_vector_callback = false; return 0; } early_param("xen_no_vector_callback", xen_parse_no_vector_callback); static __init bool xen_x2apic_available(void) { return x2apic_supported(); } static bool __init msi_ext_dest_id(void) { return cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_EXT_DEST_ID; } static __init void xen_hvm_guest_late_init(void) { #ifdef CONFIG_XEN_PVH /* Test for PVH domain (PVH boot path taken overrides ACPI flags). */ if (!xen_pvh && (x86_platform.legacy.rtc || !x86_platform.legacy.no_vga)) return; /* PVH detected. */ xen_pvh = true; if (nopv) panic("\"nopv\" and \"xen_nopv\" parameters are unsupported in PVH guest."); /* Make sure we don't fall back to (default) ACPI_IRQ_MODEL_PIC. */ if (!nr_ioapics && acpi_irq_model == ACPI_IRQ_MODEL_PIC) acpi_irq_model = ACPI_IRQ_MODEL_PLATFORM; machine_ops.emergency_restart = xen_emergency_restart; pv_info.name = "Xen PVH"; #endif } static uint32_t __init xen_platform_hvm(void) { uint32_t xen_domain = xen_cpuid_base(); struct x86_hyper_init *h = &x86_hyper_xen_hvm.init; if (xen_pv_domain()) return 0; if (xen_pvh_domain() && nopv) { /* Guest booting via the Xen-PVH boot entry goes here */ pr_info("\"nopv\" parameter is ignored in PVH guest\n"); nopv = false; } else if (nopv && xen_domain) { /* * Guest booting via normal boot entry (like via grub2) goes * here. * * Use interface functions for bare hardware if nopv, * xen_hvm_guest_late_init is an exception as we need to * detect PVH and panic there. */ h->init_platform = x86_init_noop; h->x2apic_available = bool_x86_init_noop; h->init_mem_mapping = x86_init_noop; h->init_after_bootmem = x86_init_noop; h->guest_late_init = xen_hvm_guest_late_init; x86_hyper_xen_hvm.runtime.pin_vcpu = x86_op_int_noop; } return xen_domain; } struct hypervisor_x86 x86_hyper_xen_hvm __initdata = { .name = "Xen HVM", .detect = xen_platform_hvm, .type = X86_HYPER_XEN_HVM, .init.init_platform = xen_hvm_guest_init, .init.x2apic_available = xen_x2apic_available, .init.init_mem_mapping = xen_hvm_init_mem_mapping, .init.guest_late_init = xen_hvm_guest_late_init, .init.msi_ext_dest_id = msi_ext_dest_id, .runtime.pin_vcpu = xen_pin_vcpu, .ignore_nopv = true, };