diff options
Diffstat (limited to 'arch/x86/kernel/kvm.c')
| -rw-r--r-- | arch/x86/kernel/kvm.c | 386 |
1 files changed, 273 insertions, 113 deletions
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index a26643dc6bd6..df78ddee0abb 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -27,6 +27,9 @@ #include <linux/nmi.h> #include <linux/swait.h> #include <linux/syscore_ops.h> +#include <linux/cc_platform.h> +#include <linux/efi.h> +#include <linux/kvm_types.h> #include <asm/timer.h> #include <asm/cpu.h> #include <asm/traps.h> @@ -35,13 +38,16 @@ #include <asm/apic.h> #include <asm/apicdef.h> #include <asm/hypervisor.h> +#include <asm/mtrr.h> #include <asm/tlb.h> #include <asm/cpuidle_haltpoll.h> +#include <asm/msr.h> #include <asm/ptrace.h> #include <asm/reboot.h> #include <asm/svm.h> +#include <asm/e820/api.h> -DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled); +DEFINE_STATIC_KEY_FALSE_RO(kvm_async_pf_enabled); static int kvmapf = 1; @@ -62,10 +68,12 @@ static int __init parse_no_stealacc(char *arg) early_param("no-steal-acc", parse_no_stealacc); +static DEFINE_PER_CPU_READ_MOSTLY(bool, async_pf_enabled); 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; +static int has_guest_poll = 0; /* * No need for any "IO delay" on KVM */ @@ -155,7 +163,7 @@ void kvm_async_pf_task_wait_schedule(u32 token) } finish_swait(&n.wq, &wait); } -EXPORT_SYMBOL_GPL(kvm_async_pf_task_wait_schedule); +EXPORT_SYMBOL_FOR_KVM(kvm_async_pf_task_wait_schedule); static void apf_task_wake_one(struct kvm_task_sleep_node *n) { @@ -183,11 +191,11 @@ static void apf_task_wake_all(void) } } -void kvm_async_pf_task_wake(u32 token) +static 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; + struct kvm_task_sleep_node *n, *dummy = NULL; if (token == ~0) { apf_task_wake_all(); @@ -199,43 +207,54 @@ again: n = _find_apf_task(b, token); if (!n) { /* - * async PF was not yet handled. - * Add dummy entry for the token. + * Async #PF not yet handled, add a dummy entry for the token. + * Allocating the token must be down outside of the raw lock + * as the allocator is preemptible on PREEMPT_RT kernels. */ - n = kzalloc(sizeof(*n), GFP_ATOMIC); - if (!n) { + if (!dummy) { + raw_spin_unlock(&b->lock); + dummy = kzalloc(sizeof(*dummy), GFP_ATOMIC); + /* - * Allocation failed! Busy wait while other cpu - * handles async PF. + * Continue looping on allocation failure, eventually + * the async #PF will be handled and allocating a new + * node will be unnecessary. + */ + if (!dummy) + cpu_relax(); + + /* + * Recheck for async #PF completion before enqueueing + * the dummy token to avoid duplicate list entries. */ - 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); + dummy->token = token; + dummy->cpu = smp_processor_id(); + init_swait_queue_head(&dummy->wq); + hlist_add_head(&dummy->link, &b->list); + dummy = NULL; } else { apf_task_wake_one(n); } raw_spin_unlock(&b->lock); - return; + + /* A dummy token might be allocated and ultimately not used. */ + kfree(dummy); } -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)) { + if (__this_cpu_read(async_pf_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); +EXPORT_SYMBOL_FOR_KVM(kvm_read_and_reset_apf_flags); noinstr bool __kvm_handle_async_pf(struct pt_regs *regs, u32 token) { @@ -275,15 +294,15 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_asyncpf_interrupt) struct pt_regs *old_regs = set_irq_regs(regs); u32 token; - ack_APIC_irq(); + apic_eoi(); inc_irq_stat(irq_hv_callback_count); - if (__this_cpu_read(apf_reason.enabled)) { + if (__this_cpu_read(async_pf_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); + wrmsrq(MSR_KVM_ASYNC_PF_ACK, 1); } set_irq_regs(old_regs); @@ -309,14 +328,14 @@ static void kvm_register_steal_time(void) 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, + wrmsrq(MSR_KVM_STEAL_TIME, (slow_virt_to_phys(st) | KVM_MSR_ENABLED)); + pr_debug("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) +static notrace __maybe_unused void kvm_guest_apic_eoi_write(void) { /** * This relies on __test_and_clear_bit to modify the memory @@ -327,13 +346,13 @@ static notrace void kvm_guest_apic_eoi_write(u32 reg, u32 val) */ 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); + apic_native_eoi(); } 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)); + u64 pa; WARN_ON_ONCE(!static_branch_likely(&kvm_async_pf_enabled)); @@ -343,11 +362,11 @@ static void kvm_guest_cpu_init(void) 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); + wrmsrq(MSR_KVM_ASYNC_PF_INT, HYPERVISOR_CALLBACK_VECTOR); - wrmsrl(MSR_KVM_ASYNC_PF_EN, pa); - __this_cpu_write(apf_reason.enabled, 1); - pr_info("setup async PF for cpu %d\n", smp_processor_id()); + wrmsrq(MSR_KVM_ASYNC_PF_EN, pa); + __this_cpu_write(async_pf_enabled, true); + pr_debug("setup async PF for cpu %d\n", smp_processor_id()); } if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) { @@ -358,7 +377,7 @@ static void kvm_guest_cpu_init(void) __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); + wrmsrq(MSR_KVM_PV_EOI_EN, pa); } if (has_steal_clock) @@ -367,13 +386,13 @@ static void kvm_guest_cpu_init(void) static void kvm_pv_disable_apf(void) { - if (!__this_cpu_read(apf_reason.enabled)) + if (!__this_cpu_read(async_pf_enabled)) return; - wrmsrl(MSR_KVM_ASYNC_PF_EN, 0); - __this_cpu_write(apf_reason.enabled, 0); + wrmsrq(MSR_KVM_ASYNC_PF_EN, 0); + __this_cpu_write(async_pf_enabled, false); - pr_info("disable async PF for cpu %d\n", smp_processor_id()); + pr_debug("disable async PF for cpu %d\n", smp_processor_id()); } static void kvm_disable_steal_time(void) @@ -381,7 +400,7 @@ static void kvm_disable_steal_time(void) if (!has_steal_clock) return; - wrmsr(MSR_KVM_STEAL_TIME, 0, 0); + wrmsrq(MSR_KVM_STEAL_TIME, 0); } static u64 kvm_steal_clock(int cpu) @@ -401,7 +420,7 @@ static u64 kvm_steal_clock(int cpu) return steal; } -static inline void __set_percpu_decrypted(void *ptr, unsigned long size) +static inline __init void __set_percpu_decrypted(void *ptr, unsigned long size) { early_set_memory_decrypted((unsigned long) ptr, size); } @@ -418,7 +437,8 @@ static void __init sev_map_percpu_data(void) { int cpu; - if (!sev_active()) + if (cc_vendor != CC_VENDOR_AMD || + !cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) return; for_each_possible_cpu(cpu) { @@ -432,7 +452,9 @@ static void kvm_guest_cpu_offline(bool shutdown) { kvm_disable_steal_time(); if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) - wrmsrl(MSR_KVM_PV_EOI_EN, 0); + wrmsrq(MSR_KVM_PV_EOI_EN, 0); + if (kvm_para_has_feature(KVM_FEATURE_MIGRATION_CONTROL)) + wrmsrq(MSR_KVM_MIGRATION_CONTROL, 0); kvm_pv_disable_apf(); if (!shutdown) apf_task_wake_all(); @@ -457,19 +479,24 @@ 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)); + kvm_para_has_feature(KVM_FEATURE_STEAL_TIME) && + !boot_cpu_has(X86_FEATURE_MWAIT) && + (num_possible_cpus() != 1)); } static bool pv_ipi_supported(void) { - return kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI); + return (kvm_para_has_feature(KVM_FEATURE_PV_SEND_IPI) && + (num_possible_cpus() != 1)); } 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)); + kvm_para_has_feature(KVM_FEATURE_STEAL_TIME) && + !boot_cpu_has(X86_FEATURE_MWAIT) && + (num_possible_cpus() != 1)); } #define KVM_IPI_CLUSTER_SIZE (2 * BITS_PER_LONG) @@ -477,13 +504,13 @@ static bool pv_sched_yield_supported(void) static void __send_ipi_mask(const struct cpumask *mask, int vector) { unsigned long flags; - int cpu, apic_id, icr; - int min = 0, max = 0; + int cpu, min = 0, max = 0; #ifdef CONFIG_X86_64 __uint128_t ipi_bitmap = 0; #else u64 ipi_bitmap = 0; #endif + u32 apic_id, icr; long ret; if (cpumask_empty(mask)) @@ -507,7 +534,7 @@ static void __send_ipi_mask(const struct cpumask *mask, int vector) } 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) { + } else if (apic_id > min && 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, @@ -547,13 +574,62 @@ static void kvm_send_ipi_mask_allbutself(const struct cpumask *mask, int vector) __send_ipi_mask(local_mask, vector); } +static int __init setup_efi_kvm_sev_migration(void) +{ + efi_char16_t efi_sev_live_migration_enabled[] = L"SevLiveMigrationEnabled"; + efi_guid_t efi_variable_guid = AMD_SEV_MEM_ENCRYPT_GUID; + efi_status_t status; + unsigned long size; + bool enabled; + + if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) || + !kvm_para_has_feature(KVM_FEATURE_MIGRATION_CONTROL)) + return 0; + + if (!efi_enabled(EFI_BOOT)) + return 0; + + if (!efi_enabled(EFI_RUNTIME_SERVICES)) { + pr_info("%s : EFI runtime services are not enabled\n", __func__); + return 0; + } + + size = sizeof(enabled); + + /* Get variable contents into buffer */ + status = efi.get_variable(efi_sev_live_migration_enabled, + &efi_variable_guid, NULL, &size, &enabled); + + if (status == EFI_NOT_FOUND) { + pr_info("%s : EFI live migration variable not found\n", __func__); + return 0; + } + + if (status != EFI_SUCCESS) { + pr_info("%s : EFI variable retrieval failed\n", __func__); + return 0; + } + + if (enabled == 0) { + pr_info("%s: live migration disabled in EFI\n", __func__); + return 0; + } + + pr_info("%s : live migration enabled in EFI\n", __func__); + wrmsrq(MSR_KVM_MIGRATION_CONTROL, KVM_MIGRATION_READY); + + return 1; +} + +late_initcall(setup_efi_kvm_sev_migration); + /* * Set the IPI entry points */ -static void kvm_setup_pv_ipi(void) +static __init void kvm_setup_pv_ipi(void) { - apic->send_IPI_mask = kvm_send_ipi_mask; - apic->send_IPI_mask_allbutself = kvm_send_ipi_mask_allbutself; + apic_update_callback(send_IPI_mask, kvm_send_ipi_mask); + apic_update_callback(send_IPI_mask_allbutself, kvm_send_ipi_mask_allbutself); pr_info("setup PV IPIs\n"); } @@ -565,7 +641,7 @@ static void kvm_smp_send_call_func_ipi(const struct cpumask *mask) /* Make sure other vCPUs get a chance to run if they need to. */ for_each_cpu(cpu, mask) { - if (vcpu_is_preempted(cpu)) { + if (!idle_cpu(cpu) && vcpu_is_preempted(cpu)) { kvm_hypercall1(KVM_HC_SCHED_YIELD, per_cpu(x86_cpu_to_apicid, cpu)); break; } @@ -645,23 +721,39 @@ static int kvm_cpu_down_prepare(unsigned int cpu) #endif -static int kvm_suspend(void) +static int kvm_suspend(void *data) { + u64 val = 0; + kvm_guest_cpu_offline(false); +#ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL + if (kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL)) + rdmsrq(MSR_KVM_POLL_CONTROL, val); + has_guest_poll = !(val & 1); +#endif return 0; } -static void kvm_resume(void) +static void kvm_resume(void *data) { kvm_cpu_online(raw_smp_processor_id()); + +#ifdef CONFIG_ARCH_CPUIDLE_HALTPOLL + if (kvm_para_has_feature(KVM_FEATURE_POLL_CONTROL) && has_guest_poll) + wrmsrq(MSR_KVM_POLL_CONTROL, 0); +#endif } -static struct syscore_ops kvm_syscore_ops = { +static const struct syscore_ops kvm_syscore_ops = { .suspend = kvm_suspend, .resume = kvm_resume, }; +static struct syscore kvm_syscore = { + .ops = &kvm_syscore_ops, +}; + static void kvm_pv_guest_cpu_reboot(void *unused) { kvm_guest_cpu_offline(true); @@ -685,7 +777,7 @@ static struct notifier_block kvm_pv_reboot_nb = { * won't be valid. In cases like kexec, in which you install a new kernel, this * means a random memory location will be kept being written. */ -#ifdef CONFIG_KEXEC_CORE +#ifdef CONFIG_CRASH_DUMP static void kvm_crash_shutdown(struct pt_regs *regs) { kvm_guest_cpu_offline(true); @@ -693,6 +785,36 @@ static void kvm_crash_shutdown(struct pt_regs *regs) } #endif +#if defined(CONFIG_X86_32) || !defined(CONFIG_SMP) +bool __kvm_vcpu_is_preempted(long cpu); + +__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. + */ +#define PV_VCPU_PREEMPTED_ASM \ + "movq __per_cpu_offset(,%rdi,8), %rax\n\t" \ + "cmpb $0, " __stringify(KVM_STEAL_TIME_preempted) "+steal_time(%rax)\n\t" \ + "setne %al\n\t" + +DEFINE_ASM_FUNC(__raw_callee_save___kvm_vcpu_is_preempted, + PV_VCPU_PREEMPTED_ASM, .text); +#endif + static void __init kvm_guest_init(void) { int i; @@ -705,20 +827,22 @@ static void __init kvm_guest_init(void) if (kvm_para_has_feature(KVM_FEATURE_STEAL_TIME)) { has_steal_clock = 1; static_call_update(pv_steal_clock, kvm_steal_clock); + + pv_ops.lock.vcpu_is_preempted = + PV_CALLEE_SAVE(__kvm_vcpu_is_preempted); } if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) - apic_set_eoi_write(kvm_guest_apic_eoi_write); + apic_update_callback(eoi, 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); + sysvec_install(HYPERVISOR_CALLBACK_VECTOR, sysvec_kvm_asyncpf_interrupt); } #ifdef CONFIG_SMP if (pv_tlb_flush_supported()) { pv_ops.mmu.flush_tlb_multi = kvm_flush_tlb_multi; - pv_ops.mmu.tlb_remove_table = tlb_remove_table; pr_info("KVM setup pv remote TLB flush\n"); } @@ -735,11 +859,11 @@ static void __init kvm_guest_init(void) kvm_guest_cpu_init(); #endif -#ifdef CONFIG_KEXEC_CORE +#ifdef CONFIG_CRASH_DUMP machine_ops.crash_shutdown = kvm_crash_shutdown; #endif - register_syscore_ops(&kvm_syscore_ops); + register_syscore(&kvm_syscore); /* * Hard lockup detection is enabled by default. Disable it, as guests @@ -755,7 +879,7 @@ static noinline uint32_t __kvm_cpuid_base(void) 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 cpuid_base_hypervisor(KVM_SIGNATURE, 0); return 0; } @@ -805,10 +929,82 @@ static bool __init kvm_msi_ext_dest_id(void) return kvm_para_has_feature(KVM_FEATURE_MSI_EXT_DEST_ID); } +static void kvm_sev_hc_page_enc_status(unsigned long pfn, int npages, bool enc) +{ + kvm_sev_hypercall3(KVM_HC_MAP_GPA_RANGE, pfn << PAGE_SHIFT, npages, + KVM_MAP_GPA_RANGE_ENC_STAT(enc) | KVM_MAP_GPA_RANGE_PAGE_SZ_4K); +} + static void __init kvm_init_platform(void) { + u64 tolud = PFN_PHYS(e820__end_of_low_ram_pfn()); + /* + * Note, hardware requires variable MTRR ranges to be power-of-2 sized + * and naturally aligned. But when forcing guest MTRR state, Linux + * doesn't program the forced ranges into hardware. Don't bother doing + * the math to generate a technically-legal range. + */ + struct mtrr_var_range pci_hole = { + .base_lo = tolud | X86_MEMTYPE_UC, + .mask_lo = (u32)(~(SZ_4G - tolud - 1)) | MTRR_PHYSMASK_V, + .mask_hi = (BIT_ULL(boot_cpu_data.x86_phys_bits) - 1) >> 32, + }; + + if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT) && + kvm_para_has_feature(KVM_FEATURE_MIGRATION_CONTROL)) { + unsigned long nr_pages; + int i; + + pv_ops.mmu.notify_page_enc_status_changed = + kvm_sev_hc_page_enc_status; + + /* + * Reset the host's shared pages list related to kernel + * specific page encryption status settings before we load a + * new kernel by kexec. Reset the page encryption status + * during early boot instead of just before kexec to avoid SMP + * races during kvm_pv_guest_cpu_reboot(). + * NOTE: We cannot reset the complete shared pages list + * here as we need to retain the UEFI/OVMF firmware + * specific settings. + */ + + for (i = 0; i < e820_table->nr_entries; i++) { + struct e820_entry *entry = &e820_table->entries[i]; + + if (entry->type != E820_TYPE_RAM) + continue; + + nr_pages = DIV_ROUND_UP(entry->size, PAGE_SIZE); + + kvm_sev_hypercall3(KVM_HC_MAP_GPA_RANGE, entry->addr, + nr_pages, + KVM_MAP_GPA_RANGE_ENCRYPTED | KVM_MAP_GPA_RANGE_PAGE_SZ_4K); + } + + /* + * Ensure that _bss_decrypted section is marked as decrypted in the + * shared pages list. + */ + early_set_mem_enc_dec_hypercall((unsigned long)__start_bss_decrypted, + __end_bss_decrypted - __start_bss_decrypted, 0); + + /* + * If not booted using EFI, enable Live migration support. + */ + if (!efi_enabled(EFI_BOOT)) + wrmsrq(MSR_KVM_MIGRATION_CONTROL, + KVM_MIGRATION_READY); + } kvmclock_init(); x86_platform.apic_post_init = kvm_apic_init; + + /* + * Set WB as the default cache mode for SEV-SNP and TDX, with a single + * UC range for the legacy PCI hole, e.g. so that devices that expect + * to get UC/WC mappings don't get surprised with WB. + */ + guest_force_mtrr_state(&pci_hole, 1, MTRR_TYPE_WRBACK); } #if defined(CONFIG_AMD_MEM_ENCRYPT) @@ -859,8 +1055,8 @@ arch_initcall(activate_jump_labels); /* 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; + u32 apicid; apicid = per_cpu(x86_cpu_to_apicid, cpu); kvm_hypercall2(KVM_HC_KICK_CPU, flags, apicid); @@ -884,62 +1080,20 @@ static void kvm_wait(u8 *ptr, u8 val) } else { local_irq_disable(); + /* safe_halt() will enable IRQ */ if (READ_ONCE(*ptr) == val) safe_halt(); - - local_irq_enable(); + else + local_irq_enable(); } } -#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. */ @@ -958,6 +1112,16 @@ void __init kvm_spinlock_init(void) goto out; } + /* + * 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; + } + pr_info("PV spinlocks enabled\n"); __pv_init_lock_hash(); @@ -967,10 +1131,6 @@ void __init kvm_spinlock_init(void) 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. @@ -986,12 +1146,12 @@ out: static void kvm_disable_host_haltpoll(void *i) { - wrmsrl(MSR_KVM_POLL_CONTROL, 0); + wrmsrq(MSR_KVM_POLL_CONTROL, 0); } static void kvm_enable_host_haltpoll(void *i) { - wrmsrl(MSR_KVM_POLL_CONTROL, 1); + wrmsrq(MSR_KVM_POLL_CONTROL, 1); } void arch_haltpoll_enable(unsigned int cpu) |
