// 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> */ #include <linux/context_tracking.h> #include <linux/init.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 reason = kvm_read_and_reset_apf_flags(); bool rcu_exit; switch (reason) { case KVM_PV_REASON_PAGE_NOT_PRESENT: case KVM_PV_REASON_PAGE_READY: break; default: return false; } rcu_exit = idtentry_enter_cond_rcu(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 (reason == 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 { kvm_async_pf_task_wake(token); } instrumentation_end(); idtentry_exit_cond_rcu(regs, rcu_exit); return true; } 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("kvm-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) && kvmapf) { u64 pa; 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; if (kvm_para_has_feature(KVM_FEATURE_ASYNC_PF_VMEXIT)) pa |= KVM_ASYNC_PF_DELIVERY_AS_PF_VMEXIT; 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: 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: 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("KVM 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_cpus(unsigned int max_cpus) { native_smp_prepare_cpus(max_cpus); if (kvm_para_has_hint(KVM_HINTS_REALTIME)) static_branch_disable(&virt_spin_lock_key); } 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) && kvmapf) static_branch_enable(&kvm_async_pf_enabled); #ifdef CONFIG_SMP smp_ops.smp_prepare_cpus = kvm_smp_prepare_cpus; 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("KVM 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("kvm_guest: 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) { /* Does host kernel support KVM_FEATURE_PV_UNHALT? */ if (!kvm_para_has_feature(KVM_FEATURE_PV_UNHALT)) return; if (kvm_para_has_hint(KVM_HINTS_REALTIME)) return; /* Don't use the pvqspinlock code if there is only 1 vCPU. */ if (num_possible_cpus() == 1) return; __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); } } #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("kvm: host does not support poll control\n"); pr_err_once("kvm: 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