// SPDX-License-Identifier: GPL-2.0-only /* * Local APIC virtualization * * Copyright (C) 2006 Qumranet, Inc. * Copyright (C) 2007 Novell * Copyright (C) 2007 Intel * Copyright 2009 Red Hat, Inc. and/or its affiliates. * * Authors: * Dor Laor * Gregory Haskins * Yaozu (Eddie) Dong * * Based on Xen 3.1 code, Copyright (c) 2004, Intel Corporation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "kvm_cache_regs.h" #include "irq.h" #include "ioapic.h" #include "trace.h" #include "x86.h" #include "cpuid.h" #include "hyperv.h" #ifndef CONFIG_X86_64 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y)) #else #define mod_64(x, y) ((x) % (y)) #endif #define PRId64 "d" #define PRIx64 "llx" #define PRIu64 "u" #define PRIo64 "o" /* 14 is the version for Xeon and Pentium 8.4.8*/ #define APIC_VERSION 0x14UL #define LAPIC_MMIO_LENGTH (1 << 12) /* followed define is not in apicdef.h */ #define MAX_APIC_VECTOR 256 #define APIC_VECTORS_PER_REG 32 static bool lapic_timer_advance_dynamic __read_mostly; #define LAPIC_TIMER_ADVANCE_ADJUST_MIN 100 /* clock cycles */ #define LAPIC_TIMER_ADVANCE_ADJUST_MAX 10000 /* clock cycles */ #define LAPIC_TIMER_ADVANCE_NS_INIT 1000 #define LAPIC_TIMER_ADVANCE_NS_MAX 5000 /* step-by-step approximation to mitigate fluctuation */ #define LAPIC_TIMER_ADVANCE_ADJUST_STEP 8 static int kvm_lapic_msr_read(struct kvm_lapic *apic, u32 reg, u64 *data); static int kvm_lapic_msr_write(struct kvm_lapic *apic, u32 reg, u64 data); static inline void __kvm_lapic_set_reg(char *regs, int reg_off, u32 val) { *((u32 *) (regs + reg_off)) = val; } static inline void kvm_lapic_set_reg(struct kvm_lapic *apic, int reg_off, u32 val) { __kvm_lapic_set_reg(apic->regs, reg_off, val); } static __always_inline u64 __kvm_lapic_get_reg64(char *regs, int reg) { BUILD_BUG_ON(reg != APIC_ICR); return *((u64 *) (regs + reg)); } static __always_inline u64 kvm_lapic_get_reg64(struct kvm_lapic *apic, int reg) { return __kvm_lapic_get_reg64(apic->regs, reg); } static __always_inline void __kvm_lapic_set_reg64(char *regs, int reg, u64 val) { BUILD_BUG_ON(reg != APIC_ICR); *((u64 *) (regs + reg)) = val; } static __always_inline void kvm_lapic_set_reg64(struct kvm_lapic *apic, int reg, u64 val) { __kvm_lapic_set_reg64(apic->regs, reg, val); } static inline int apic_test_vector(int vec, void *bitmap) { return test_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); } bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector) { struct kvm_lapic *apic = vcpu->arch.apic; return apic_test_vector(vector, apic->regs + APIC_ISR) || apic_test_vector(vector, apic->regs + APIC_IRR); } static inline int __apic_test_and_set_vector(int vec, void *bitmap) { return __test_and_set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); } static inline int __apic_test_and_clear_vector(int vec, void *bitmap) { return __test_and_clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); } __read_mostly DEFINE_STATIC_KEY_DEFERRED_FALSE(apic_hw_disabled, HZ); __read_mostly DEFINE_STATIC_KEY_DEFERRED_FALSE(apic_sw_disabled, HZ); static inline int apic_enabled(struct kvm_lapic *apic) { return kvm_apic_sw_enabled(apic) && kvm_apic_hw_enabled(apic); } #define LVT_MASK \ (APIC_LVT_MASKED | APIC_SEND_PENDING | APIC_VECTOR_MASK) #define LINT_MASK \ (LVT_MASK | APIC_MODE_MASK | APIC_INPUT_POLARITY | \ APIC_LVT_REMOTE_IRR | APIC_LVT_LEVEL_TRIGGER) static inline u32 kvm_x2apic_id(struct kvm_lapic *apic) { return apic->vcpu->vcpu_id; } static bool kvm_can_post_timer_interrupt(struct kvm_vcpu *vcpu) { return pi_inject_timer && kvm_vcpu_apicv_active(vcpu) && (kvm_mwait_in_guest(vcpu->kvm) || kvm_hlt_in_guest(vcpu->kvm)); } bool kvm_can_use_hv_timer(struct kvm_vcpu *vcpu) { return kvm_x86_ops.set_hv_timer && !(kvm_mwait_in_guest(vcpu->kvm) || kvm_can_post_timer_interrupt(vcpu)); } EXPORT_SYMBOL_GPL(kvm_can_use_hv_timer); static bool kvm_use_posted_timer_interrupt(struct kvm_vcpu *vcpu) { return kvm_can_post_timer_interrupt(vcpu) && vcpu->mode == IN_GUEST_MODE; } static inline bool kvm_apic_map_get_logical_dest(struct kvm_apic_map *map, u32 dest_id, struct kvm_lapic ***cluster, u16 *mask) { switch (map->mode) { case KVM_APIC_MODE_X2APIC: { u32 offset = (dest_id >> 16) * 16; u32 max_apic_id = map->max_apic_id; if (offset <= max_apic_id) { u8 cluster_size = min(max_apic_id - offset + 1, 16U); offset = array_index_nospec(offset, map->max_apic_id + 1); *cluster = &map->phys_map[offset]; *mask = dest_id & (0xffff >> (16 - cluster_size)); } else { *mask = 0; } return true; } case KVM_APIC_MODE_XAPIC_FLAT: *cluster = map->xapic_flat_map; *mask = dest_id & 0xff; return true; case KVM_APIC_MODE_XAPIC_CLUSTER: *cluster = map->xapic_cluster_map[(dest_id >> 4) & 0xf]; *mask = dest_id & 0xf; return true; default: /* Not optimized. */ return false; } } static void kvm_apic_map_free(struct rcu_head *rcu) { struct kvm_apic_map *map = container_of(rcu, struct kvm_apic_map, rcu); kvfree(map); } /* * CLEAN -> DIRTY and UPDATE_IN_PROGRESS -> DIRTY changes happen without a lock. * * DIRTY -> UPDATE_IN_PROGRESS and UPDATE_IN_PROGRESS -> CLEAN happen with * apic_map_lock_held. */ enum { CLEAN, UPDATE_IN_PROGRESS, DIRTY }; void kvm_recalculate_apic_map(struct kvm *kvm) { struct kvm_apic_map *new, *old = NULL; struct kvm_vcpu *vcpu; unsigned long i; u32 max_id = 255; /* enough space for any xAPIC ID */ /* Read kvm->arch.apic_map_dirty before kvm->arch.apic_map. */ if (atomic_read_acquire(&kvm->arch.apic_map_dirty) == CLEAN) return; WARN_ONCE(!irqchip_in_kernel(kvm), "Dirty APIC map without an in-kernel local APIC"); mutex_lock(&kvm->arch.apic_map_lock); /* * Read kvm->arch.apic_map_dirty before kvm->arch.apic_map * (if clean) or the APIC registers (if dirty). */ if (atomic_cmpxchg_acquire(&kvm->arch.apic_map_dirty, DIRTY, UPDATE_IN_PROGRESS) == CLEAN) { /* Someone else has updated the map. */ mutex_unlock(&kvm->arch.apic_map_lock); return; } kvm_for_each_vcpu(i, vcpu, kvm) if (kvm_apic_present(vcpu)) max_id = max(max_id, kvm_x2apic_id(vcpu->arch.apic)); new = kvzalloc(sizeof(struct kvm_apic_map) + sizeof(struct kvm_lapic *) * ((u64)max_id + 1), GFP_KERNEL_ACCOUNT); if (!new) goto out; new->max_apic_id = max_id; kvm_for_each_vcpu(i, vcpu, kvm) { struct kvm_lapic *apic = vcpu->arch.apic; struct kvm_lapic **cluster; u16 mask; u32 ldr; u8 xapic_id; u32 x2apic_id; if (!kvm_apic_present(vcpu)) continue; xapic_id = kvm_xapic_id(apic); x2apic_id = kvm_x2apic_id(apic); /* Hotplug hack: see kvm_apic_match_physical_addr(), ... */ if ((apic_x2apic_mode(apic) || x2apic_id > 0xff) && x2apic_id <= new->max_apic_id) new->phys_map[x2apic_id] = apic; /* * ... xAPIC ID of VCPUs with APIC ID > 0xff will wrap-around, * prevent them from masking VCPUs with APIC ID <= 0xff. */ if (!apic_x2apic_mode(apic) && !new->phys_map[xapic_id]) new->phys_map[xapic_id] = apic; if (!kvm_apic_sw_enabled(apic)) continue; ldr = kvm_lapic_get_reg(apic, APIC_LDR); if (apic_x2apic_mode(apic)) { new->mode |= KVM_APIC_MODE_X2APIC; } else if (ldr) { ldr = GET_APIC_LOGICAL_ID(ldr); if (kvm_lapic_get_reg(apic, APIC_DFR) == APIC_DFR_FLAT) new->mode |= KVM_APIC_MODE_XAPIC_FLAT; else new->mode |= KVM_APIC_MODE_XAPIC_CLUSTER; } if (!kvm_apic_map_get_logical_dest(new, ldr, &cluster, &mask)) continue; if (mask) cluster[ffs(mask) - 1] = apic; } out: old = rcu_dereference_protected(kvm->arch.apic_map, lockdep_is_held(&kvm->arch.apic_map_lock)); rcu_assign_pointer(kvm->arch.apic_map, new); /* * Write kvm->arch.apic_map before clearing apic->apic_map_dirty. * If another update has come in, leave it DIRTY. */ atomic_cmpxchg_release(&kvm->arch.apic_map_dirty, UPDATE_IN_PROGRESS, CLEAN); mutex_unlock(&kvm->arch.apic_map_lock); if (old) call_rcu(&old->rcu, kvm_apic_map_free); kvm_make_scan_ioapic_request(kvm); } static inline void apic_set_spiv(struct kvm_lapic *apic, u32 val) { bool enabled = val & APIC_SPIV_APIC_ENABLED; kvm_lapic_set_reg(apic, APIC_SPIV, val); if (enabled != apic->sw_enabled) { apic->sw_enabled = enabled; if (enabled) static_branch_slow_dec_deferred(&apic_sw_disabled); else static_branch_inc(&apic_sw_disabled.key); atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY); } /* Check if there are APF page ready requests pending */ if (enabled) kvm_make_request(KVM_REQ_APF_READY, apic->vcpu); } static inline void kvm_apic_set_xapic_id(struct kvm_lapic *apic, u8 id) { kvm_lapic_set_reg(apic, APIC_ID, id << 24); atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY); } static inline void kvm_apic_set_ldr(struct kvm_lapic *apic, u32 id) { kvm_lapic_set_reg(apic, APIC_LDR, id); atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY); } static inline void kvm_apic_set_dfr(struct kvm_lapic *apic, u32 val) { kvm_lapic_set_reg(apic, APIC_DFR, val); atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY); } static inline u32 kvm_apic_calc_x2apic_ldr(u32 id) { return ((id >> 4) << 16) | (1 << (id & 0xf)); } static inline void kvm_apic_set_x2apic_id(struct kvm_lapic *apic, u32 id) { u32 ldr = kvm_apic_calc_x2apic_ldr(id); WARN_ON_ONCE(id != apic->vcpu->vcpu_id); kvm_lapic_set_reg(apic, APIC_ID, id); kvm_lapic_set_reg(apic, APIC_LDR, ldr); atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY); } static inline int apic_lvt_enabled(struct kvm_lapic *apic, int lvt_type) { return !(kvm_lapic_get_reg(apic, lvt_type) & APIC_LVT_MASKED); } static inline int apic_lvtt_oneshot(struct kvm_lapic *apic) { return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_ONESHOT; } static inline int apic_lvtt_period(struct kvm_lapic *apic) { return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_PERIODIC; } static inline int apic_lvtt_tscdeadline(struct kvm_lapic *apic) { return apic->lapic_timer.timer_mode == APIC_LVT_TIMER_TSCDEADLINE; } static inline int apic_lvt_nmi_mode(u32 lvt_val) { return (lvt_val & (APIC_MODE_MASK | APIC_LVT_MASKED)) == APIC_DM_NMI; } static inline bool kvm_lapic_lvt_supported(struct kvm_lapic *apic, int lvt_index) { return apic->nr_lvt_entries > lvt_index; } static inline int kvm_apic_calc_nr_lvt_entries(struct kvm_vcpu *vcpu) { return KVM_APIC_MAX_NR_LVT_ENTRIES - !(vcpu->arch.mcg_cap & MCG_CMCI_P); } void kvm_apic_set_version(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; u32 v = 0; if (!lapic_in_kernel(vcpu)) return; v = APIC_VERSION | ((apic->nr_lvt_entries - 1) << 16); /* * KVM emulates 82093AA datasheet (with in-kernel IOAPIC implementation) * which doesn't have EOI register; Some buggy OSes (e.g. Windows with * Hyper-V role) disable EOI broadcast in lapic not checking for IOAPIC * version first and level-triggered interrupts never get EOIed in * IOAPIC. */ if (guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) && !ioapic_in_kernel(vcpu->kvm)) v |= APIC_LVR_DIRECTED_EOI; kvm_lapic_set_reg(apic, APIC_LVR, v); } void kvm_apic_after_set_mcg_cap(struct kvm_vcpu *vcpu) { int nr_lvt_entries = kvm_apic_calc_nr_lvt_entries(vcpu); struct kvm_lapic *apic = vcpu->arch.apic; int i; if (!lapic_in_kernel(vcpu) || nr_lvt_entries == apic->nr_lvt_entries) return; /* Initialize/mask any "new" LVT entries. */ for (i = apic->nr_lvt_entries; i < nr_lvt_entries; i++) kvm_lapic_set_reg(apic, APIC_LVTx(i), APIC_LVT_MASKED); apic->nr_lvt_entries = nr_lvt_entries; /* The number of LVT entries is reflected in the version register. */ kvm_apic_set_version(vcpu); } static const unsigned int apic_lvt_mask[KVM_APIC_MAX_NR_LVT_ENTRIES] = { [LVT_TIMER] = LVT_MASK, /* timer mode mask added at runtime */ [LVT_THERMAL_MONITOR] = LVT_MASK | APIC_MODE_MASK, [LVT_PERFORMANCE_COUNTER] = LVT_MASK | APIC_MODE_MASK, [LVT_LINT0] = LINT_MASK, [LVT_LINT1] = LINT_MASK, [LVT_ERROR] = LVT_MASK, [LVT_CMCI] = LVT_MASK | APIC_MODE_MASK }; static int find_highest_vector(void *bitmap) { int vec; u32 *reg; for (vec = MAX_APIC_VECTOR - APIC_VECTORS_PER_REG; vec >= 0; vec -= APIC_VECTORS_PER_REG) { reg = bitmap + REG_POS(vec); if (*reg) return __fls(*reg) + vec; } return -1; } static u8 count_vectors(void *bitmap) { int vec; u32 *reg; u8 count = 0; for (vec = 0; vec < MAX_APIC_VECTOR; vec += APIC_VECTORS_PER_REG) { reg = bitmap + REG_POS(vec); count += hweight32(*reg); } return count; } bool __kvm_apic_update_irr(u32 *pir, void *regs, int *max_irr) { u32 i, vec; u32 pir_val, irr_val, prev_irr_val; int max_updated_irr; max_updated_irr = -1; *max_irr = -1; for (i = vec = 0; i <= 7; i++, vec += 32) { pir_val = READ_ONCE(pir[i]); irr_val = *((u32 *)(regs + APIC_IRR + i * 0x10)); if (pir_val) { prev_irr_val = irr_val; irr_val |= xchg(&pir[i], 0); *((u32 *)(regs + APIC_IRR + i * 0x10)) = irr_val; if (prev_irr_val != irr_val) { max_updated_irr = __fls(irr_val ^ prev_irr_val) + vec; } } if (irr_val) *max_irr = __fls(irr_val) + vec; } return ((max_updated_irr != -1) && (max_updated_irr == *max_irr)); } EXPORT_SYMBOL_GPL(__kvm_apic_update_irr); bool kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir, int *max_irr) { struct kvm_lapic *apic = vcpu->arch.apic; return __kvm_apic_update_irr(pir, apic->regs, max_irr); } EXPORT_SYMBOL_GPL(kvm_apic_update_irr); static inline int apic_search_irr(struct kvm_lapic *apic) { return find_highest_vector(apic->regs + APIC_IRR); } static inline int apic_find_highest_irr(struct kvm_lapic *apic) { int result; /* * Note that irr_pending is just a hint. It will be always * true with virtual interrupt delivery enabled. */ if (!apic->irr_pending) return -1; result = apic_search_irr(apic); ASSERT(result == -1 || result >= 16); return result; } static inline void apic_clear_irr(int vec, struct kvm_lapic *apic) { if (unlikely(apic->apicv_active)) { /* need to update RVI */ kvm_lapic_clear_vector(vec, apic->regs + APIC_IRR); static_call_cond(kvm_x86_hwapic_irr_update)(apic->vcpu, apic_find_highest_irr(apic)); } else { apic->irr_pending = false; kvm_lapic_clear_vector(vec, apic->regs + APIC_IRR); if (apic_search_irr(apic) != -1) apic->irr_pending = true; } } void kvm_apic_clear_irr(struct kvm_vcpu *vcpu, int vec) { apic_clear_irr(vec, vcpu->arch.apic); } EXPORT_SYMBOL_GPL(kvm_apic_clear_irr); static inline void apic_set_isr(int vec, struct kvm_lapic *apic) { if (__apic_test_and_set_vector(vec, apic->regs + APIC_ISR)) return; /* * With APIC virtualization enabled, all caching is disabled * because the processor can modify ISR under the hood. Instead * just set SVI. */ if (unlikely(apic->apicv_active)) static_call_cond(kvm_x86_hwapic_isr_update)(vec); else { ++apic->isr_count; BUG_ON(apic->isr_count > MAX_APIC_VECTOR); /* * ISR (in service register) bit is set when injecting an interrupt. * The highest vector is injected. Thus the latest bit set matches * the highest bit in ISR. */ apic->highest_isr_cache = vec; } } static inline int apic_find_highest_isr(struct kvm_lapic *apic) { int result; /* * Note that isr_count is always 1, and highest_isr_cache * is always -1, with APIC virtualization enabled. */ if (!apic->isr_count) return -1; if (likely(apic->highest_isr_cache != -1)) return apic->highest_isr_cache; result = find_highest_vector(apic->regs + APIC_ISR); ASSERT(result == -1 || result >= 16); return result; } static inline void apic_clear_isr(int vec, struct kvm_lapic *apic) { if (!__apic_test_and_clear_vector(vec, apic->regs + APIC_ISR)) return; /* * We do get here for APIC virtualization enabled if the guest * uses the Hyper-V APIC enlightenment. In this case we may need * to trigger a new interrupt delivery by writing the SVI field; * on the other hand isr_count and highest_isr_cache are unused * and must be left alone. */ if (unlikely(apic->apicv_active)) static_call_cond(kvm_x86_hwapic_isr_update)(apic_find_highest_isr(apic)); else { --apic->isr_count; BUG_ON(apic->isr_count < 0); apic->highest_isr_cache = -1; } } int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu) { /* This may race with setting of irr in __apic_accept_irq() and * value returned may be wrong, but kvm_vcpu_kick() in __apic_accept_irq * will cause vmexit immediately and the value will be recalculated * on the next vmentry. */ return apic_find_highest_irr(vcpu->arch.apic); } EXPORT_SYMBOL_GPL(kvm_lapic_find_highest_irr); static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, int vector, int level, int trig_mode, struct dest_map *dest_map); int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq, struct dest_map *dest_map) { struct kvm_lapic *apic = vcpu->arch.apic; return __apic_accept_irq(apic, irq->delivery_mode, irq->vector, irq->level, irq->trig_mode, dest_map); } static int __pv_send_ipi(unsigned long *ipi_bitmap, struct kvm_apic_map *map, struct kvm_lapic_irq *irq, u32 min) { int i, count = 0; struct kvm_vcpu *vcpu; if (min > map->max_apic_id) return 0; for_each_set_bit(i, ipi_bitmap, min((u32)BITS_PER_LONG, (map->max_apic_id - min + 1))) { if (map->phys_map[min + i]) { vcpu = map->phys_map[min + i]->vcpu; count += kvm_apic_set_irq(vcpu, irq, NULL); } } return count; } int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low, unsigned long ipi_bitmap_high, u32 min, unsigned long icr, int op_64_bit) { struct kvm_apic_map *map; struct kvm_lapic_irq irq = {0}; int cluster_size = op_64_bit ? 64 : 32; int count; if (icr & (APIC_DEST_MASK | APIC_SHORT_MASK)) return -KVM_EINVAL; irq.vector = icr & APIC_VECTOR_MASK; irq.delivery_mode = icr & APIC_MODE_MASK; irq.level = (icr & APIC_INT_ASSERT) != 0; irq.trig_mode = icr & APIC_INT_LEVELTRIG; rcu_read_lock(); map = rcu_dereference(kvm->arch.apic_map); count = -EOPNOTSUPP; if (likely(map)) { count = __pv_send_ipi(&ipi_bitmap_low, map, &irq, min); min += cluster_size; count += __pv_send_ipi(&ipi_bitmap_high, map, &irq, min); } rcu_read_unlock(); return count; } static int pv_eoi_put_user(struct kvm_vcpu *vcpu, u8 val) { return kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data, &val, sizeof(val)); } static int pv_eoi_get_user(struct kvm_vcpu *vcpu, u8 *val) { return kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.pv_eoi.data, val, sizeof(*val)); } static inline bool pv_eoi_enabled(struct kvm_vcpu *vcpu) { return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED; } static void pv_eoi_set_pending(struct kvm_vcpu *vcpu) { if (pv_eoi_put_user(vcpu, KVM_PV_EOI_ENABLED) < 0) return; __set_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention); } static bool pv_eoi_test_and_clr_pending(struct kvm_vcpu *vcpu) { u8 val; if (pv_eoi_get_user(vcpu, &val) < 0) return false; val &= KVM_PV_EOI_ENABLED; if (val && pv_eoi_put_user(vcpu, KVM_PV_EOI_DISABLED) < 0) return false; /* * Clear pending bit in any case: it will be set again on vmentry. * While this might not be ideal from performance point of view, * this makes sure pv eoi is only enabled when we know it's safe. */ __clear_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention); return val; } static int apic_has_interrupt_for_ppr(struct kvm_lapic *apic, u32 ppr) { int highest_irr; if (kvm_x86_ops.sync_pir_to_irr) highest_irr = static_call(kvm_x86_sync_pir_to_irr)(apic->vcpu); else highest_irr = apic_find_highest_irr(apic); if (highest_irr == -1 || (highest_irr & 0xF0) <= ppr) return -1; return highest_irr; } static bool __apic_update_ppr(struct kvm_lapic *apic, u32 *new_ppr) { u32 tpr, isrv, ppr, old_ppr; int isr; old_ppr = kvm_lapic_get_reg(apic, APIC_PROCPRI); tpr = kvm_lapic_get_reg(apic, APIC_TASKPRI); isr = apic_find_highest_isr(apic); isrv = (isr != -1) ? isr : 0; if ((tpr & 0xf0) >= (isrv & 0xf0)) ppr = tpr & 0xff; else ppr = isrv & 0xf0; *new_ppr = ppr; if (old_ppr != ppr) kvm_lapic_set_reg(apic, APIC_PROCPRI, ppr); return ppr < old_ppr; } static void apic_update_ppr(struct kvm_lapic *apic) { u32 ppr; if (__apic_update_ppr(apic, &ppr) && apic_has_interrupt_for_ppr(apic, ppr) != -1) kvm_make_request(KVM_REQ_EVENT, apic->vcpu); } void kvm_apic_update_ppr(struct kvm_vcpu *vcpu) { apic_update_ppr(vcpu->arch.apic); } EXPORT_SYMBOL_GPL(kvm_apic_update_ppr); static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr) { kvm_lapic_set_reg(apic, APIC_TASKPRI, tpr); apic_update_ppr(apic); } static bool kvm_apic_broadcast(struct kvm_lapic *apic, u32 mda) { return mda == (apic_x2apic_mode(apic) ? X2APIC_BROADCAST : APIC_BROADCAST); } static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda) { if (kvm_apic_broadcast(apic, mda)) return true; /* * Hotplug hack: Accept interrupts for vCPUs in xAPIC mode as if they * were in x2APIC mode if the target APIC ID can't be encoded as an * xAPIC ID. This allows unique addressing of hotplugged vCPUs (which * start in xAPIC mode) with an APIC ID that is unaddressable in xAPIC * mode. Match the x2APIC ID if and only if the target APIC ID can't * be encoded in xAPIC to avoid spurious matches against a vCPU that * changed its (addressable) xAPIC ID (which is writable). */ if (apic_x2apic_mode(apic) || mda > 0xff) return mda == kvm_x2apic_id(apic); return mda == kvm_xapic_id(apic); } static bool kvm_apic_match_logical_addr(struct kvm_lapic *apic, u32 mda) { u32 logical_id; if (kvm_apic_broadcast(apic, mda)) return true; logical_id = kvm_lapic_get_reg(apic, APIC_LDR); if (apic_x2apic_mode(apic)) return ((logical_id >> 16) == (mda >> 16)) && (logical_id & mda & 0xffff) != 0; logical_id = GET_APIC_LOGICAL_ID(logical_id); switch (kvm_lapic_get_reg(apic, APIC_DFR)) { case APIC_DFR_FLAT: return (logical_id & mda) != 0; case APIC_DFR_CLUSTER: return ((logical_id >> 4) == (mda >> 4)) && (logical_id & mda & 0xf) != 0; default: return false; } } /* The KVM local APIC implementation has two quirks: * * - Real hardware delivers interrupts destined to x2APIC ID > 0xff to LAPICs * in xAPIC mode if the "destination & 0xff" matches its xAPIC ID. * KVM doesn't do that aliasing. * * - in-kernel IOAPIC messages have to be delivered directly to * x2APIC, because the kernel does not support interrupt remapping. * In order to support broadcast without interrupt remapping, x2APIC * rewrites the destination of non-IPI messages from APIC_BROADCAST * to X2APIC_BROADCAST. * * The broadcast quirk can be disabled with KVM_CAP_X2APIC_API. This is * important when userspace wants to use x2APIC-format MSIs, because * APIC_BROADCAST (0xff) is a legal route for "cluster 0, CPUs 0-7". */ static u32 kvm_apic_mda(struct kvm_vcpu *vcpu, unsigned int dest_id, struct kvm_lapic *source, struct kvm_lapic *target) { bool ipi = source != NULL; if (!vcpu->kvm->arch.x2apic_broadcast_quirk_disabled && !ipi && dest_id == APIC_BROADCAST && apic_x2apic_mode(target)) return X2APIC_BROADCAST; return dest_id; } bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source, int shorthand, unsigned int dest, int dest_mode) { struct kvm_lapic *target = vcpu->arch.apic; u32 mda = kvm_apic_mda(vcpu, dest, source, target); ASSERT(target); switch (shorthand) { case APIC_DEST_NOSHORT: if (dest_mode == APIC_DEST_PHYSICAL) return kvm_apic_match_physical_addr(target, mda); else return kvm_apic_match_logical_addr(target, mda); case APIC_DEST_SELF: return target == source; case APIC_DEST_ALLINC: return true; case APIC_DEST_ALLBUT: return target != source; default: return false; } } EXPORT_SYMBOL_GPL(kvm_apic_match_dest); int kvm_vector_to_index(u32 vector, u32 dest_vcpus, const unsigned long *bitmap, u32 bitmap_size) { u32 mod; int i, idx = -1; mod = vector % dest_vcpus; for (i = 0; i <= mod; i++) { idx = find_next_bit(bitmap, bitmap_size, idx + 1); BUG_ON(idx == bitmap_size); } return idx; } static void kvm_apic_disabled_lapic_found(struct kvm *kvm) { if (!kvm->arch.disabled_lapic_found) { kvm->arch.disabled_lapic_found = true; printk(KERN_INFO "Disabled LAPIC found during irq injection\n"); } } static bool kvm_apic_is_broadcast_dest(struct kvm *kvm, struct kvm_lapic **src, struct kvm_lapic_irq *irq, struct kvm_apic_map *map) { if (kvm->arch.x2apic_broadcast_quirk_disabled) { if ((irq->dest_id == APIC_BROADCAST && map->mode != KVM_APIC_MODE_X2APIC)) return true; if (irq->dest_id == X2APIC_BROADCAST) return true; } else { bool x2apic_ipi = src && *src && apic_x2apic_mode(*src); if (irq->dest_id == (x2apic_ipi ? X2APIC_BROADCAST : APIC_BROADCAST)) return true; } return false; } /* Return true if the interrupt can be handled by using *bitmap as index mask * for valid destinations in *dst array. * Return false if kvm_apic_map_get_dest_lapic did nothing useful. * Note: we may have zero kvm_lapic destinations when we return true, which * means that the interrupt should be dropped. In this case, *bitmap would be * zero and *dst undefined. */ static inline bool kvm_apic_map_get_dest_lapic(struct kvm *kvm, struct kvm_lapic **src, struct kvm_lapic_irq *irq, struct kvm_apic_map *map, struct kvm_lapic ***dst, unsigned long *bitmap) { int i, lowest; if (irq->shorthand == APIC_DEST_SELF && src) { *dst = src; *bitmap = 1; return true; } else if (irq->shorthand) return false; if (!map || kvm_apic_is_broadcast_dest(kvm, src, irq, map)) return false; if (irq->dest_mode == APIC_DEST_PHYSICAL) { if (irq->dest_id > map->max_apic_id) { *bitmap = 0; } else { u32 dest_id = array_index_nospec(irq->dest_id, map->max_apic_id + 1); *dst = &map->phys_map[dest_id]; *bitmap = 1; } return true; } *bitmap = 0; if (!kvm_apic_map_get_logical_dest(map, irq->dest_id, dst, (u16 *)bitmap)) return false; if (!kvm_lowest_prio_delivery(irq)) return true; if (!kvm_vector_hashing_enabled()) { lowest = -1; for_each_set_bit(i, bitmap, 16) { if (!(*dst)[i]) continue; if (lowest < 0) lowest = i; else if (kvm_apic_compare_prio((*dst)[i]->vcpu, (*dst)[lowest]->vcpu) < 0) lowest = i; } } else { if (!*bitmap) return true; lowest = kvm_vector_to_index(irq->vector, hweight16(*bitmap), bitmap, 16); if (!(*dst)[lowest]) { kvm_apic_disabled_lapic_found(kvm); *bitmap = 0; return true; } } *bitmap = (lowest >= 0) ? 1 << lowest : 0; return true; } bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, struct kvm_lapic_irq *irq, int *r, struct dest_map *dest_map) { struct kvm_apic_map *map; unsigned long bitmap; struct kvm_lapic **dst = NULL; int i; bool ret; *r = -1; if (irq->shorthand == APIC_DEST_SELF) { if (KVM_BUG_ON(!src, kvm)) { *r = 0; return true; } *r = kvm_apic_set_irq(src->vcpu, irq, dest_map); return true; } rcu_read_lock(); map = rcu_dereference(kvm->arch.apic_map); ret = kvm_apic_map_get_dest_lapic(kvm, &src, irq, map, &dst, &bitmap); if (ret) { *r = 0; for_each_set_bit(i, &bitmap, 16) { if (!dst[i]) continue; *r += kvm_apic_set_irq(dst[i]->vcpu, irq, dest_map); } } rcu_read_unlock(); return ret; } /* * This routine tries to handle interrupts in posted mode, here is how * it deals with different cases: * - For single-destination interrupts, handle it in posted mode * - Else if vector hashing is enabled and it is a lowest-priority * interrupt, handle it in posted mode and use the following mechanism * to find the destination vCPU. * 1. For lowest-priority interrupts, store all the possible * destination vCPUs in an array. * 2. Use "guest vector % max number of destination vCPUs" to find * the right destination vCPU in the array for the lowest-priority * interrupt. * - Otherwise, use remapped mode to inject the interrupt. */ bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq, struct kvm_vcpu **dest_vcpu) { struct kvm_apic_map *map; unsigned long bitmap; struct kvm_lapic **dst = NULL; bool ret = false; if (irq->shorthand) return false; rcu_read_lock(); map = rcu_dereference(kvm->arch.apic_map); if (kvm_apic_map_get_dest_lapic(kvm, NULL, irq, map, &dst, &bitmap) && hweight16(bitmap) == 1) { unsigned long i = find_first_bit(&bitmap, 16); if (dst[i]) { *dest_vcpu = dst[i]->vcpu; ret = true; } } rcu_read_unlock(); return ret; } /* * Add a pending IRQ into lapic. * Return 1 if successfully added and 0 if discarded. */ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, int vector, int level, int trig_mode, struct dest_map *dest_map) { int result = 0; struct kvm_vcpu *vcpu = apic->vcpu; trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode, trig_mode, vector); switch (delivery_mode) { case APIC_DM_LOWEST: vcpu->arch.apic_arb_prio++; fallthrough; case APIC_DM_FIXED: if (unlikely(trig_mode && !level)) break; /* FIXME add logic for vcpu on reset */ if (unlikely(!apic_enabled(apic))) break; result = 1; if (dest_map) { __set_bit(vcpu->vcpu_id, dest_map->map); dest_map->vectors[vcpu->vcpu_id] = vector; } if (apic_test_vector(vector, apic->regs + APIC_TMR) != !!trig_mode) { if (trig_mode) kvm_lapic_set_vector(vector, apic->regs + APIC_TMR); else kvm_lapic_clear_vector(vector, apic->regs + APIC_TMR); } static_call(kvm_x86_deliver_interrupt)(apic, delivery_mode, trig_mode, vector); break; case APIC_DM_REMRD: result = 1; vcpu->arch.pv.pv_unhalted = 1; kvm_make_request(KVM_REQ_EVENT, vcpu); kvm_vcpu_kick(vcpu); break; case APIC_DM_SMI: result = 1; kvm_make_request(KVM_REQ_SMI, vcpu); kvm_vcpu_kick(vcpu); break; case APIC_DM_NMI: result = 1; kvm_inject_nmi(vcpu); kvm_vcpu_kick(vcpu); break; case APIC_DM_INIT: if (!trig_mode || level) { result = 1; /* assumes that there are only KVM_APIC_INIT/SIPI */ apic->pending_events = (1UL << KVM_APIC_INIT); kvm_make_request(KVM_REQ_EVENT, vcpu); kvm_vcpu_kick(vcpu); } break; case APIC_DM_STARTUP: result = 1; apic->sipi_vector = vector; /* make sure sipi_vector is visible for the receiver */ smp_wmb(); set_bit(KVM_APIC_SIPI, &apic->pending_events); kvm_make_request(KVM_REQ_EVENT, vcpu); kvm_vcpu_kick(vcpu); break; case APIC_DM_EXTINT: /* * Should only be called by kvm_apic_local_deliver() with LVT0, * before NMI watchdog was enabled. Already handled by * kvm_apic_accept_pic_intr(). */ break; default: printk(KERN_ERR "TODO: unsupported delivery mode %x\n", delivery_mode); break; } return result; } /* * This routine identifies the destination vcpus mask meant to receive the * IOAPIC interrupts. It either uses kvm_apic_map_get_dest_lapic() to find * out the destination vcpus array and set the bitmap or it traverses to * each available vcpu to identify the same. */ void kvm_bitmap_or_dest_vcpus(struct kvm *kvm, struct kvm_lapic_irq *irq, unsigned long *vcpu_bitmap) { struct kvm_lapic **dest_vcpu = NULL; struct kvm_lapic *src = NULL; struct kvm_apic_map *map; struct kvm_vcpu *vcpu; unsigned long bitmap, i; int vcpu_idx; bool ret; rcu_read_lock(); map = rcu_dereference(kvm->arch.apic_map); ret = kvm_apic_map_get_dest_lapic(kvm, &src, irq, map, &dest_vcpu, &bitmap); if (ret) { for_each_set_bit(i, &bitmap, 16) { if (!dest_vcpu[i]) continue; vcpu_idx = dest_vcpu[i]->vcpu->vcpu_idx; __set_bit(vcpu_idx, vcpu_bitmap); } } else { kvm_for_each_vcpu(i, vcpu, kvm) { if (!kvm_apic_present(vcpu)) continue; if (!kvm_apic_match_dest(vcpu, NULL, irq->shorthand, irq->dest_id, irq->dest_mode)) continue; __set_bit(i, vcpu_bitmap); } } rcu_read_unlock(); } int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2) { return vcpu1->arch.apic_arb_prio - vcpu2->arch.apic_arb_prio; } static bool kvm_ioapic_handles_vector(struct kvm_lapic *apic, int vector) { return test_bit(vector, apic->vcpu->arch.ioapic_handled_vectors); } static void kvm_ioapic_send_eoi(struct kvm_lapic *apic, int vector) { int trigger_mode; /* Eoi the ioapic only if the ioapic doesn't own the vector. */ if (!kvm_ioapic_handles_vector(apic, vector)) return; /* Request a KVM exit to inform the userspace IOAPIC. */ if (irqchip_split(apic->vcpu->kvm)) { apic->vcpu->arch.pending_ioapic_eoi = vector; kvm_make_request(KVM_REQ_IOAPIC_EOI_EXIT, apic->vcpu); return; } if (apic_test_vector(vector, apic->regs + APIC_TMR)) trigger_mode = IOAPIC_LEVEL_TRIG; else trigger_mode = IOAPIC_EDGE_TRIG; kvm_ioapic_update_eoi(apic->vcpu, vector, trigger_mode); } static int apic_set_eoi(struct kvm_lapic *apic) { int vector = apic_find_highest_isr(apic); trace_kvm_eoi(apic, vector); /* * Not every write EOI will has corresponding ISR, * one example is when Kernel check timer on setup_IO_APIC */ if (vector == -1) return vector; apic_clear_isr(vector, apic); apic_update_ppr(apic); if (to_hv_vcpu(apic->vcpu) && test_bit(vector, to_hv_synic(apic->vcpu)->vec_bitmap)) kvm_hv_synic_send_eoi(apic->vcpu, vector); kvm_ioapic_send_eoi(apic, vector); kvm_make_request(KVM_REQ_EVENT, apic->vcpu); return vector; } /* * this interface assumes a trap-like exit, which has already finished * desired side effect including vISR and vPPR update. */ void kvm_apic_set_eoi_accelerated(struct kvm_vcpu *vcpu, int vector) { struct kvm_lapic *apic = vcpu->arch.apic; trace_kvm_eoi(apic, vector); kvm_ioapic_send_eoi(apic, vector); kvm_make_request(KVM_REQ_EVENT, apic->vcpu); } EXPORT_SYMBOL_GPL(kvm_apic_set_eoi_accelerated); void kvm_apic_send_ipi(struct kvm_lapic *apic, u32 icr_low, u32 icr_high) { struct kvm_lapic_irq irq; /* KVM has no delay and should always clear the BUSY/PENDING flag. */ WARN_ON_ONCE(icr_low & APIC_ICR_BUSY); irq.vector = icr_low & APIC_VECTOR_MASK; irq.delivery_mode = icr_low & APIC_MODE_MASK; irq.dest_mode = icr_low & APIC_DEST_MASK; irq.level = (icr_low & APIC_INT_ASSERT) != 0; irq.trig_mode = icr_low & APIC_INT_LEVELTRIG; irq.shorthand = icr_low & APIC_SHORT_MASK; irq.msi_redir_hint = false; if (apic_x2apic_mode(apic)) irq.dest_id = icr_high; else irq.dest_id = GET_XAPIC_DEST_FIELD(icr_high); trace_kvm_apic_ipi(icr_low, irq.dest_id); kvm_irq_delivery_to_apic(apic->vcpu->kvm, apic, &irq, NULL); } EXPORT_SYMBOL_GPL(kvm_apic_send_ipi); static u32 apic_get_tmcct(struct kvm_lapic *apic) { ktime_t remaining, now; s64 ns; u32 tmcct; ASSERT(apic != NULL); /* if initial count is 0, current count should also be 0 */ if (kvm_lapic_get_reg(apic, APIC_TMICT) == 0 || apic->lapic_timer.period == 0) return 0; now = ktime_get(); remaining = ktime_sub(apic->lapic_timer.target_expiration, now); if (ktime_to_ns(remaining) < 0) remaining = 0; ns = mod_64(ktime_to_ns(remaining), apic->lapic_timer.period); tmcct = div64_u64(ns, (APIC_BUS_CYCLE_NS * apic->divide_count)); return tmcct; } static void __report_tpr_access(struct kvm_lapic *apic, bool write) { struct kvm_vcpu *vcpu = apic->vcpu; struct kvm_run *run = vcpu->run; kvm_make_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu); run->tpr_access.rip = kvm_rip_read(vcpu); run->tpr_access.is_write = write; } static inline void report_tpr_access(struct kvm_lapic *apic, bool write) { if (apic->vcpu->arch.tpr_access_reporting) __report_tpr_access(apic, write); } static u32 __apic_read(struct kvm_lapic *apic, unsigned int offset) { u32 val = 0; if (offset >= LAPIC_MMIO_LENGTH) return 0; switch (offset) { case APIC_ARBPRI: break; case APIC_TMCCT: /* Timer CCR */ if (apic_lvtt_tscdeadline(apic)) return 0; val = apic_get_tmcct(apic); break; case APIC_PROCPRI: apic_update_ppr(apic); val = kvm_lapic_get_reg(apic, offset); break; case APIC_TASKPRI: report_tpr_access(apic, false); fallthrough; default: val = kvm_lapic_get_reg(apic, offset); break; } return val; } static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev) { return container_of(dev, struct kvm_lapic, dev); } #define APIC_REG_MASK(reg) (1ull << ((reg) >> 4)) #define APIC_REGS_MASK(first, count) \ (APIC_REG_MASK(first) * ((1ull << (count)) - 1)) static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, void *data) { unsigned char alignment = offset & 0xf; u32 result; /* this bitmask has a bit cleared for each reserved register */ u64 valid_reg_mask = APIC_REG_MASK(APIC_ID) | APIC_REG_MASK(APIC_LVR) | APIC_REG_MASK(APIC_TASKPRI) | APIC_REG_MASK(APIC_PROCPRI) | APIC_REG_MASK(APIC_LDR) | APIC_REG_MASK(APIC_DFR) | APIC_REG_MASK(APIC_SPIV) | APIC_REGS_MASK(APIC_ISR, APIC_ISR_NR) | APIC_REGS_MASK(APIC_TMR, APIC_ISR_NR) | APIC_REGS_MASK(APIC_IRR, APIC_ISR_NR) | APIC_REG_MASK(APIC_ESR) | APIC_REG_MASK(APIC_ICR) | APIC_REG_MASK(APIC_LVTT) | APIC_REG_MASK(APIC_LVTTHMR) | APIC_REG_MASK(APIC_LVTPC) | APIC_REG_MASK(APIC_LVT0) | APIC_REG_MASK(APIC_LVT1) | APIC_REG_MASK(APIC_LVTERR) | APIC_REG_MASK(APIC_TMICT) | APIC_REG_MASK(APIC_TMCCT) | APIC_REG_MASK(APIC_TDCR); if (kvm_lapic_lvt_supported(apic, LVT_CMCI)) valid_reg_mask |= APIC_REG_MASK(APIC_LVTCMCI); /* * ARBPRI and ICR2 are not valid in x2APIC mode. WARN if KVM reads ICR * in x2APIC mode as it's an 8-byte register in x2APIC and needs to be * manually handled by the caller. */ if (!apic_x2apic_mode(apic)) valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI) | APIC_REG_MASK(APIC_ICR2); else WARN_ON_ONCE(offset == APIC_ICR); if (alignment + len > 4) return 1; if (offset > 0x3f0 || !(valid_reg_mask & APIC_REG_MASK(offset))) return 1; result = __apic_read(apic, offset & ~0xf); trace_kvm_apic_read(offset, result); switch (len) { case 1: case 2: case 4: memcpy(data, (char *)&result + alignment, len); break; default: printk(KERN_ERR "Local APIC read with len = %x, " "should be 1,2, or 4 instead\n", len); break; } return 0; } static int apic_mmio_in_range(struct kvm_lapic *apic, gpa_t addr) { return addr >= apic->base_address && addr < apic->base_address + LAPIC_MMIO_LENGTH; } static int apic_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *this, gpa_t address, int len, void *data) { struct kvm_lapic *apic = to_lapic(this); u32 offset = address - apic->base_address; if (!apic_mmio_in_range(apic, address)) return -EOPNOTSUPP; if (!kvm_apic_hw_enabled(apic) || apic_x2apic_mode(apic)) { if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_LAPIC_MMIO_HOLE)) return -EOPNOTSUPP; memset(data, 0xff, len); return 0; } kvm_lapic_reg_read(apic, offset, len, data); return 0; } static void update_divide_count(struct kvm_lapic *apic) { u32 tmp1, tmp2, tdcr; tdcr = kvm_lapic_get_reg(apic, APIC_TDCR); tmp1 = tdcr & 0xf; tmp2 = ((tmp1 & 0x3) | ((tmp1 & 0x8) >> 1)) + 1; apic->divide_count = 0x1 << (tmp2 & 0x7); } static void limit_periodic_timer_frequency(struct kvm_lapic *apic) { /* * Do not allow the guest to program periodic timers with small * interval, since the hrtimers are not throttled by the host * scheduler. */ if (apic_lvtt_period(apic) && apic->lapic_timer.period) { s64 min_period = min_timer_period_us * 1000LL; if (apic->lapic_timer.period < min_period) { pr_info_ratelimited( "kvm: vcpu %i: requested %lld ns " "lapic timer period limited to %lld ns\n", apic->vcpu->vcpu_id, apic->lapic_timer.period, min_period); apic->lapic_timer.period = min_period; } } } static void cancel_hv_timer(struct kvm_lapic *apic); static void cancel_apic_timer(struct kvm_lapic *apic) { hrtimer_cancel(&apic->lapic_timer.timer); preempt_disable(); if (apic->lapic_timer.hv_timer_in_use) cancel_hv_timer(apic); preempt_enable(); atomic_set(&apic->lapic_timer.pending, 0); } static void apic_update_lvtt(struct kvm_lapic *apic) { u32 timer_mode = kvm_lapic_get_reg(apic, APIC_LVTT) & apic->lapic_timer.timer_mode_mask; if (apic->lapic_timer.timer_mode != timer_mode) { if (apic_lvtt_tscdeadline(apic) != (timer_mode == APIC_LVT_TIMER_TSCDEADLINE)) { cancel_apic_timer(apic); kvm_lapic_set_reg(apic, APIC_TMICT, 0); apic->lapic_timer.period = 0; apic->lapic_timer.tscdeadline = 0; } apic->lapic_timer.timer_mode = timer_mode; limit_periodic_timer_frequency(apic); } } /* * On APICv, this test will cause a busy wait * during a higher-priority task. */ static bool lapic_timer_int_injected(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; u32 reg = kvm_lapic_get_reg(apic, APIC_LVTT); if (kvm_apic_hw_enabled(apic)) { int vec = reg & APIC_VECTOR_MASK; void *bitmap = apic->regs + APIC_ISR; if (apic->apicv_active) bitmap = apic->regs + APIC_IRR; if (apic_test_vector(vec, bitmap)) return true; } return false; } static inline void __wait_lapic_expire(struct kvm_vcpu *vcpu, u64 guest_cycles) { u64 timer_advance_ns = vcpu->arch.apic->lapic_timer.timer_advance_ns; /* * If the guest TSC is running at a different ratio than the host, then * convert the delay to nanoseconds to achieve an accurate delay. Note * that __delay() uses delay_tsc whenever the hardware has TSC, thus * always for VMX enabled hardware. */ if (vcpu->arch.tsc_scaling_ratio == kvm_caps.default_tsc_scaling_ratio) { __delay(min(guest_cycles, nsec_to_cycles(vcpu, timer_advance_ns))); } else { u64 delay_ns = guest_cycles * 1000000ULL; do_div(delay_ns, vcpu->arch.virtual_tsc_khz); ndelay(min_t(u32, delay_ns, timer_advance_ns)); } } static inline void adjust_lapic_timer_advance(struct kvm_vcpu *vcpu, s64 advance_expire_delta) { struct kvm_lapic *apic = vcpu->arch.apic; u32 timer_advance_ns = apic->lapic_timer.timer_advance_ns; u64 ns; /* Do not adjust for tiny fluctuations or large random spikes. */ if (abs(advance_expire_delta) > LAPIC_TIMER_ADVANCE_ADJUST_MAX || abs(advance_expire_delta) < LAPIC_TIMER_ADVANCE_ADJUST_MIN) return; /* too early */ if (advance_expire_delta < 0) { ns = -advance_expire_delta * 1000000ULL; do_div(ns, vcpu->arch.virtual_tsc_khz); timer_advance_ns -= ns/LAPIC_TIMER_ADVANCE_ADJUST_STEP; } else { /* too late */ ns = advance_expire_delta * 1000000ULL; do_div(ns, vcpu->arch.virtual_tsc_khz); timer_advance_ns += ns/LAPIC_TIMER_ADVANCE_ADJUST_STEP; } if (unlikely(timer_advance_ns > LAPIC_TIMER_ADVANCE_NS_MAX)) timer_advance_ns = LAPIC_TIMER_ADVANCE_NS_INIT; apic->lapic_timer.timer_advance_ns = timer_advance_ns; } static void __kvm_wait_lapic_expire(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; u64 guest_tsc, tsc_deadline; tsc_deadline = apic->lapic_timer.expired_tscdeadline; apic->lapic_timer.expired_tscdeadline = 0; guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc()); trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline); if (lapic_timer_advance_dynamic) { adjust_lapic_timer_advance(vcpu, guest_tsc - tsc_deadline); /* * If the timer fired early, reread the TSC to account for the * overhead of the above adjustment to avoid waiting longer * than is necessary. */ if (guest_tsc < tsc_deadline) guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc()); } if (guest_tsc < tsc_deadline) __wait_lapic_expire(vcpu, tsc_deadline - guest_tsc); } void kvm_wait_lapic_expire(struct kvm_vcpu *vcpu) { if (lapic_in_kernel(vcpu) && vcpu->arch.apic->lapic_timer.expired_tscdeadline && vcpu->arch.apic->lapic_timer.timer_advance_ns && lapic_timer_int_injected(vcpu)) __kvm_wait_lapic_expire(vcpu); } EXPORT_SYMBOL_GPL(kvm_wait_lapic_expire); static void kvm_apic_inject_pending_timer_irqs(struct kvm_lapic *apic) { struct kvm_timer *ktimer = &apic->lapic_timer; kvm_apic_local_deliver(apic, APIC_LVTT); if (apic_lvtt_tscdeadline(apic)) { ktimer->tscdeadline = 0; } else if (apic_lvtt_oneshot(apic)) { ktimer->tscdeadline = 0; ktimer->target_expiration = 0; } } static void apic_timer_expired(struct kvm_lapic *apic, bool from_timer_fn) { struct kvm_vcpu *vcpu = apic->vcpu; struct kvm_timer *ktimer = &apic->lapic_timer; if (atomic_read(&apic->lapic_timer.pending)) return; if (apic_lvtt_tscdeadline(apic) || ktimer->hv_timer_in_use) ktimer->expired_tscdeadline = ktimer->tscdeadline; if (!from_timer_fn && apic->apicv_active) { WARN_ON(kvm_get_running_vcpu() != vcpu); kvm_apic_inject_pending_timer_irqs(apic); return; } if (kvm_use_posted_timer_interrupt(apic->vcpu)) { /* * Ensure the guest's timer has truly expired before posting an * interrupt. Open code the relevant checks to avoid querying * lapic_timer_int_injected(), which will be false since the * interrupt isn't yet injected. Waiting until after injecting * is not an option since that won't help a posted interrupt. */ if (vcpu->arch.apic->lapic_timer.expired_tscdeadline && vcpu->arch.apic->lapic_timer.timer_advance_ns) __kvm_wait_lapic_expire(vcpu); kvm_apic_inject_pending_timer_irqs(apic); return; } atomic_inc(&apic->lapic_timer.pending); kvm_make_request(KVM_REQ_UNBLOCK, vcpu); if (from_timer_fn) kvm_vcpu_kick(vcpu); } static void start_sw_tscdeadline(struct kvm_lapic *apic) { struct kvm_timer *ktimer = &apic->lapic_timer; u64 guest_tsc, tscdeadline = ktimer->tscdeadline; u64 ns = 0; ktime_t expire; struct kvm_vcpu *vcpu = apic->vcpu; unsigned long this_tsc_khz = vcpu->arch.virtual_tsc_khz; unsigned long flags; ktime_t now; if (unlikely(!tscdeadline || !this_tsc_khz)) return; local_irq_save(flags); now = ktime_get(); guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc()); ns = (tscdeadline - guest_tsc) * 1000000ULL; do_div(ns, this_tsc_khz); if (likely(tscdeadline > guest_tsc) && likely(ns > apic->lapic_timer.timer_advance_ns)) { expire = ktime_add_ns(now, ns); expire = ktime_sub_ns(expire, ktimer->timer_advance_ns); hrtimer_start(&ktimer->timer, expire, HRTIMER_MODE_ABS_HARD); } else apic_timer_expired(apic, false); local_irq_restore(flags); } static inline u64 tmict_to_ns(struct kvm_lapic *apic, u32 tmict) { return (u64)tmict * APIC_BUS_CYCLE_NS * (u64)apic->divide_count; } static void update_target_expiration(struct kvm_lapic *apic, uint32_t old_divisor) { ktime_t now, remaining; u64 ns_remaining_old, ns_remaining_new; apic->lapic_timer.period = tmict_to_ns(apic, kvm_lapic_get_reg(apic, APIC_TMICT)); limit_periodic_timer_frequency(apic); now = ktime_get(); remaining = ktime_sub(apic->lapic_timer.target_expiration, now); if (ktime_to_ns(remaining) < 0) remaining = 0; ns_remaining_old = ktime_to_ns(remaining); ns_remaining_new = mul_u64_u32_div(ns_remaining_old, apic->divide_count, old_divisor); apic->lapic_timer.tscdeadline += nsec_to_cycles(apic->vcpu, ns_remaining_new) - nsec_to_cycles(apic->vcpu, ns_remaining_old); apic->lapic_timer.target_expiration = ktime_add_ns(now, ns_remaining_new); } static bool set_target_expiration(struct kvm_lapic *apic, u32 count_reg) { ktime_t now; u64 tscl = rdtsc(); s64 deadline; now = ktime_get(); apic->lapic_timer.period = tmict_to_ns(apic, kvm_lapic_get_reg(apic, APIC_TMICT)); if (!apic->lapic_timer.period) { apic->lapic_timer.tscdeadline = 0; return false; } limit_periodic_timer_frequency(apic); deadline = apic->lapic_timer.period; if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) { if (unlikely(count_reg != APIC_TMICT)) { deadline = tmict_to_ns(apic, kvm_lapic_get_reg(apic, count_reg)); if (unlikely(deadline <= 0)) deadline = apic->lapic_timer.period; else if (unlikely(deadline > apic->lapic_timer.period)) { pr_info_ratelimited( "kvm: vcpu %i: requested lapic timer restore with " "starting count register %#x=%u (%lld ns) > initial count (%lld ns). " "Using initial count to start timer.\n", apic->vcpu->vcpu_id, count_reg, kvm_lapic_get_reg(apic, count_reg), deadline, apic->lapic_timer.period); kvm_lapic_set_reg(apic, count_reg, 0); deadline = apic->lapic_timer.period; } } } apic->lapic_timer.tscdeadline = kvm_read_l1_tsc(apic->vcpu, tscl) + nsec_to_cycles(apic->vcpu, deadline); apic->lapic_timer.target_expiration = ktime_add_ns(now, deadline); return true; } static void advance_periodic_target_expiration(struct kvm_lapic *apic) { ktime_t now = ktime_get(); u64 tscl = rdtsc(); ktime_t delta; /* * Synchronize both deadlines to the same time source or * differences in the periods (caused by differences in the * underlying clocks or numerical approximation errors) will * cause the two to drift apart over time as the errors * accumulate. */ apic->lapic_timer.target_expiration = ktime_add_ns(apic->lapic_timer.target_expiration, apic->lapic_timer.period); delta = ktime_sub(apic->lapic_timer.target_expiration, now); apic->lapic_timer.tscdeadline = kvm_read_l1_tsc(apic->vcpu, tscl) + nsec_to_cycles(apic->vcpu, delta); } static void start_sw_period(struct kvm_lapic *apic) { if (!apic->lapic_timer.period) return; if (ktime_after(ktime_get(), apic->lapic_timer.target_expiration)) { apic_timer_expired(apic, false); if (apic_lvtt_oneshot(apic)) return; advance_periodic_target_expiration(apic); } hrtimer_start(&apic->lapic_timer.timer, apic->lapic_timer.target_expiration, HRTIMER_MODE_ABS_HARD); } bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu) { if (!lapic_in_kernel(vcpu)) return false; return vcpu->arch.apic->lapic_timer.hv_timer_in_use; } EXPORT_SYMBOL_GPL(kvm_lapic_hv_timer_in_use); static void cancel_hv_timer(struct kvm_lapic *apic) { WARN_ON(preemptible()); WARN_ON(!apic->lapic_timer.hv_timer_in_use); static_call(kvm_x86_cancel_hv_timer)(apic->vcpu); apic->lapic_timer.hv_timer_in_use = false; } static bool start_hv_timer(struct kvm_lapic *apic) { struct kvm_timer *ktimer = &apic->lapic_timer; struct kvm_vcpu *vcpu = apic->vcpu; bool expired; WARN_ON(preemptible()); if (!kvm_can_use_hv_timer(vcpu)) return false; if (!ktimer->tscdeadline) return false; if (static_call(kvm_x86_set_hv_timer)(vcpu, ktimer->tscdeadline, &expired)) return false; ktimer->hv_timer_in_use = true; hrtimer_cancel(&ktimer->timer); /* * To simplify handling the periodic timer, leave the hv timer running * even if the deadline timer has expired, i.e. rely on the resulting * VM-Exit to recompute the periodic timer's target expiration. */ if (!apic_lvtt_period(apic)) { /* * Cancel the hv timer if the sw timer fired while the hv timer * was being programmed, or if the hv timer itself expired. */ if (atomic_read(&ktimer->pending)) { cancel_hv_timer(apic); } else if (expired) { apic_timer_expired(apic, false); cancel_hv_timer(apic); } } trace_kvm_hv_timer_state(vcpu->vcpu_id, ktimer->hv_timer_in_use); return true; } static void start_sw_timer(struct kvm_lapic *apic) { struct kvm_timer *ktimer = &apic->lapic_timer; WARN_ON(preemptible()); if (apic->lapic_timer.hv_timer_in_use) cancel_hv_timer(apic); if (!apic_lvtt_period(apic) && atomic_read(&ktimer->pending)) return; if (apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) start_sw_period(apic); else if (apic_lvtt_tscdeadline(apic)) start_sw_tscdeadline(apic); trace_kvm_hv_timer_state(apic->vcpu->vcpu_id, false); } static void restart_apic_timer(struct kvm_lapic *apic) { preempt_disable(); if (!apic_lvtt_period(apic) && atomic_read(&apic->lapic_timer.pending)) goto out; if (!start_hv_timer(apic)) start_sw_timer(apic); out: preempt_enable(); } void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; preempt_disable(); /* If the preempt notifier has already run, it also called apic_timer_expired */ if (!apic->lapic_timer.hv_timer_in_use) goto out; WARN_ON(kvm_vcpu_is_blocking(vcpu)); apic_timer_expired(apic, false); cancel_hv_timer(apic); if (apic_lvtt_period(apic) && apic->lapic_timer.period) { advance_periodic_target_expiration(apic); restart_apic_timer(apic); } out: preempt_enable(); } EXPORT_SYMBOL_GPL(kvm_lapic_expired_hv_timer); void kvm_lapic_switch_to_hv_timer(struct kvm_vcpu *vcpu) { restart_apic_timer(vcpu->arch.apic); } void kvm_lapic_switch_to_sw_timer(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; preempt_disable(); /* Possibly the TSC deadline timer is not enabled yet */ if (apic->lapic_timer.hv_timer_in_use) start_sw_timer(apic); preempt_enable(); } void kvm_lapic_restart_hv_timer(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; WARN_ON(!apic->lapic_timer.hv_timer_in_use); restart_apic_timer(apic); } static void __start_apic_timer(struct kvm_lapic *apic, u32 count_reg) { atomic_set(&apic->lapic_timer.pending, 0); if ((apic_lvtt_period(apic) || apic_lvtt_oneshot(apic)) && !set_target_expiration(apic, count_reg)) return; restart_apic_timer(apic); } static void start_apic_timer(struct kvm_lapic *apic) { __start_apic_timer(apic, APIC_TMICT); } static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val) { bool lvt0_in_nmi_mode = apic_lvt_nmi_mode(lvt0_val); if (apic->lvt0_in_nmi_mode != lvt0_in_nmi_mode) { apic->lvt0_in_nmi_mode = lvt0_in_nmi_mode; if (lvt0_in_nmi_mode) { atomic_inc(&apic->vcpu->kvm->arch.vapics_in_nmi_mode); } else atomic_dec(&apic->vcpu->kvm->arch.vapics_in_nmi_mode); } } static void kvm_lapic_xapic_id_updated(struct kvm_lapic *apic) { struct kvm *kvm = apic->vcpu->kvm; if (!kvm_apic_hw_enabled(apic)) return; if (KVM_BUG_ON(apic_x2apic_mode(apic), kvm)) return; /* * Deliberately truncate the vCPU ID when detecting a modified APIC ID * to avoid false positives if the vCPU ID, i.e. x2APIC ID, is a 32-bit * value. */ if (kvm_xapic_id(apic) == (u8)apic->vcpu->vcpu_id) return; kvm_set_apicv_inhibit(apic->vcpu->kvm, APICV_INHIBIT_REASON_APIC_ID_MODIFIED); } static int get_lvt_index(u32 reg) { if (reg == APIC_LVTCMCI) return LVT_CMCI; if (reg < APIC_LVTT || reg > APIC_LVTERR) return -1; return array_index_nospec( (reg - APIC_LVTT) >> 4, KVM_APIC_MAX_NR_LVT_ENTRIES); } static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) { int ret = 0; trace_kvm_apic_write(reg, val); switch (reg) { case APIC_ID: /* Local APIC ID */ if (!apic_x2apic_mode(apic)) { kvm_apic_set_xapic_id(apic, val >> 24); kvm_lapic_xapic_id_updated(apic); } else { ret = 1; } break; case APIC_TASKPRI: report_tpr_access(apic, true); apic_set_tpr(apic, val & 0xff); break; case APIC_EOI: apic_set_eoi(apic); break; case APIC_LDR: if (!apic_x2apic_mode(apic)) kvm_apic_set_ldr(apic, val & APIC_LDR_MASK); else ret = 1; break; case APIC_DFR: if (!apic_x2apic_mode(apic)) kvm_apic_set_dfr(apic, val | 0x0FFFFFFF); else ret = 1; break; case APIC_SPIV: { u32 mask = 0x3ff; if (kvm_lapic_get_reg(apic, APIC_LVR) & APIC_LVR_DIRECTED_EOI) mask |= APIC_SPIV_DIRECTED_EOI; apic_set_spiv(apic, val & mask); if (!(val & APIC_SPIV_APIC_ENABLED)) { int i; for (i = 0; i < apic->nr_lvt_entries; i++) { kvm_lapic_set_reg(apic, APIC_LVTx(i), kvm_lapic_get_reg(apic, APIC_LVTx(i)) | APIC_LVT_MASKED); } apic_update_lvtt(apic); atomic_set(&apic->lapic_timer.pending, 0); } break; } case APIC_ICR: WARN_ON_ONCE(apic_x2apic_mode(apic)); /* No delay here, so we always clear the pending bit */ val &= ~APIC_ICR_BUSY; kvm_apic_send_ipi(apic, val, kvm_lapic_get_reg(apic, APIC_ICR2)); kvm_lapic_set_reg(apic, APIC_ICR, val); break; case APIC_ICR2: if (apic_x2apic_mode(apic)) ret = 1; else kvm_lapic_set_reg(apic, APIC_ICR2, val & 0xff000000); break; case APIC_LVT0: apic_manage_nmi_watchdog(apic, val); fallthrough; case APIC_LVTTHMR: case APIC_LVTPC: case APIC_LVT1: case APIC_LVTERR: case APIC_LVTCMCI: { u32 index = get_lvt_index(reg); if (!kvm_lapic_lvt_supported(apic, index)) { ret = 1; break; } if (!kvm_apic_sw_enabled(apic)) val |= APIC_LVT_MASKED; val &= apic_lvt_mask[index]; kvm_lapic_set_reg(apic, reg, val); break; } case APIC_LVTT: if (!kvm_apic_sw_enabled(apic)) val |= APIC_LVT_MASKED; val &= (apic_lvt_mask[0] | apic->lapic_timer.timer_mode_mask); kvm_lapic_set_reg(apic, APIC_LVTT, val); apic_update_lvtt(apic); break; case APIC_TMICT: if (apic_lvtt_tscdeadline(apic)) break; cancel_apic_timer(apic); kvm_lapic_set_reg(apic, APIC_TMICT, val); start_apic_timer(apic); break; case APIC_TDCR: { uint32_t old_divisor = apic->divide_count; kvm_lapic_set_reg(apic, APIC_TDCR, val & 0xb); update_divide_count(apic); if (apic->divide_count != old_divisor && apic->lapic_timer.period) { hrtimer_cancel(&apic->lapic_timer.timer); update_target_expiration(apic, old_divisor); restart_apic_timer(apic); } break; } case APIC_ESR: if (apic_x2apic_mode(apic) && val != 0) ret = 1; break; case APIC_SELF_IPI: /* * Self-IPI exists only when x2APIC is enabled. Bits 7:0 hold * the vector, everything else is reserved. */ if (!apic_x2apic_mode(apic) || (val & ~APIC_VECTOR_MASK)) ret = 1; else kvm_apic_send_ipi(apic, APIC_DEST_SELF | val, 0); break; default: ret = 1; break; } /* * Recalculate APIC maps if necessary, e.g. if the software enable bit * was toggled, the APIC ID changed, etc... The maps are marked dirty * on relevant changes, i.e. this is a nop for most writes. */ kvm_recalculate_apic_map(apic->vcpu->kvm); return ret; } static int apic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this, gpa_t address, int len, const void *data) { struct kvm_lapic *apic = to_lapic(this); unsigned int offset = address - apic->base_address; u32 val; if (!apic_mmio_in_range(apic, address)) return -EOPNOTSUPP; if (!kvm_apic_hw_enabled(apic) || apic_x2apic_mode(apic)) { if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_LAPIC_MMIO_HOLE)) return -EOPNOTSUPP; return 0; } /* * APIC register must be aligned on 128-bits boundary. * 32/64/128 bits registers must be accessed thru 32 bits. * Refer SDM 8.4.1 */ if (len != 4 || (offset & 0xf)) return 0; val = *(u32*)data; kvm_lapic_reg_write(apic, offset & 0xff0, val); return 0; } void kvm_lapic_set_eoi(struct kvm_vcpu *vcpu) { kvm_lapic_reg_write(vcpu->arch.apic, APIC_EOI, 0); } EXPORT_SYMBOL_GPL(kvm_lapic_set_eoi); /* emulate APIC access in a trap manner */ void kvm_apic_write_nodecode(struct kvm_vcpu *vcpu, u32 offset) { struct kvm_lapic *apic = vcpu->arch.apic; u64 val; /* * ICR is a single 64-bit register when x2APIC is enabled. For legacy * xAPIC, ICR writes need to go down the common (slightly slower) path * to get the upper half from ICR2. */ if (apic_x2apic_mode(apic) && offset == APIC_ICR) { val = kvm_lapic_get_reg64(apic, APIC_ICR); kvm_apic_send_ipi(apic, (u32)val, (u32)(val >> 32)); trace_kvm_apic_write(APIC_ICR, val); } else { /* TODO: optimize to just emulate side effect w/o one more write */ val = kvm_lapic_get_reg(apic, offset); kvm_lapic_reg_write(apic, offset, (u32)val); } } EXPORT_SYMBOL_GPL(kvm_apic_write_nodecode); void kvm_free_lapic(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; if (!vcpu->arch.apic) return; hrtimer_cancel(&apic->lapic_timer.timer); if (!(vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)) static_branch_slow_dec_deferred(&apic_hw_disabled); if (!apic->sw_enabled) static_branch_slow_dec_deferred(&apic_sw_disabled); if (apic->regs) free_page((unsigned long)apic->regs); kfree(apic); } /* *---------------------------------------------------------------------- * LAPIC interface *---------------------------------------------------------------------- */ u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; if (!kvm_apic_present(vcpu) || !apic_lvtt_tscdeadline(apic)) return 0; return apic->lapic_timer.tscdeadline; } void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data) { struct kvm_lapic *apic = vcpu->arch.apic; if (!kvm_apic_present(vcpu) || !apic_lvtt_tscdeadline(apic)) return; hrtimer_cancel(&apic->lapic_timer.timer); apic->lapic_timer.tscdeadline = data; start_apic_timer(apic); } void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8) { apic_set_tpr(vcpu->arch.apic, (cr8 & 0x0f) << 4); } u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu) { u64 tpr; tpr = (u64) kvm_lapic_get_reg(vcpu->arch.apic, APIC_TASKPRI); return (tpr & 0xf0) >> 4; } void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) { u64 old_value = vcpu->arch.apic_base; struct kvm_lapic *apic = vcpu->arch.apic; vcpu->arch.apic_base = value; if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) kvm_update_cpuid_runtime(vcpu); if (!apic) return; /* update jump label if enable bit changes */ if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) { if (value & MSR_IA32_APICBASE_ENABLE) { kvm_apic_set_xapic_id(apic, vcpu->vcpu_id); static_branch_slow_dec_deferred(&apic_hw_disabled); /* Check if there are APF page ready requests pending */ kvm_make_request(KVM_REQ_APF_READY, vcpu); } else { static_branch_inc(&apic_hw_disabled.key); atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY); } } if (((old_value ^ value) & X2APIC_ENABLE) && (value & X2APIC_ENABLE)) kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id); if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) { kvm_vcpu_update_apicv(vcpu); static_call_cond(kvm_x86_set_virtual_apic_mode)(vcpu); } apic->base_address = apic->vcpu->arch.apic_base & MSR_IA32_APICBASE_BASE; if ((value & MSR_IA32_APICBASE_ENABLE) && apic->base_address != APIC_DEFAULT_PHYS_BASE) { kvm_set_apicv_inhibit(apic->vcpu->kvm, APICV_INHIBIT_REASON_APIC_BASE_MODIFIED); } } void kvm_apic_update_apicv(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; if (apic->apicv_active) { /* irr_pending is always true when apicv is activated. */ apic->irr_pending = true; apic->isr_count = 1; } else { /* * Don't clear irr_pending, searching the IRR can race with * updates from the CPU as APICv is still active from hardware's * perspective. The flag will be cleared as appropriate when * KVM injects the interrupt. */ apic->isr_count = count_vectors(apic->regs + APIC_ISR); } apic->highest_isr_cache = -1; } EXPORT_SYMBOL_GPL(kvm_apic_update_apicv); void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) { struct kvm_lapic *apic = vcpu->arch.apic; u64 msr_val; int i; if (!init_event) { msr_val = APIC_DEFAULT_PHYS_BASE | MSR_IA32_APICBASE_ENABLE; if (kvm_vcpu_is_reset_bsp(vcpu)) msr_val |= MSR_IA32_APICBASE_BSP; kvm_lapic_set_base(vcpu, msr_val); } if (!apic) return; /* Stop the timer in case it's a reset to an active apic */ hrtimer_cancel(&apic->lapic_timer.timer); /* The xAPIC ID is set at RESET even if the APIC was already enabled. */ if (!init_event) kvm_apic_set_xapic_id(apic, vcpu->vcpu_id); kvm_apic_set_version(apic->vcpu); for (i = 0; i < apic->nr_lvt_entries; i++) kvm_lapic_set_reg(apic, APIC_LVTx(i), APIC_LVT_MASKED); apic_update_lvtt(apic); if (kvm_vcpu_is_reset_bsp(vcpu) && kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_LINT0_REENABLED)) kvm_lapic_set_reg(apic, APIC_LVT0, SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT)); apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0)); kvm_apic_set_dfr(apic, 0xffffffffU); apic_set_spiv(apic, 0xff); kvm_lapic_set_reg(apic, APIC_TASKPRI, 0); if (!apic_x2apic_mode(apic)) kvm_apic_set_ldr(apic, 0); kvm_lapic_set_reg(apic, APIC_ESR, 0); if (!apic_x2apic_mode(apic)) { kvm_lapic_set_reg(apic, APIC_ICR, 0); kvm_lapic_set_reg(apic, APIC_ICR2, 0); } else { kvm_lapic_set_reg64(apic, APIC_ICR, 0); } kvm_lapic_set_reg(apic, APIC_TDCR, 0); kvm_lapic_set_reg(apic, APIC_TMICT, 0); for (i = 0; i < 8; i++) { kvm_lapic_set_reg(apic, APIC_IRR + 0x10 * i, 0); kvm_lapic_set_reg(apic, APIC_ISR + 0x10 * i, 0); kvm_lapic_set_reg(apic, APIC_TMR + 0x10 * i, 0); } kvm_apic_update_apicv(vcpu); update_divide_count(apic); atomic_set(&apic->lapic_timer.pending, 0); vcpu->arch.pv_eoi.msr_val = 0; apic_update_ppr(apic); if (apic->apicv_active) { static_call_cond(kvm_x86_apicv_post_state_restore)(vcpu); static_call_cond(kvm_x86_hwapic_irr_update)(vcpu, -1); static_call_cond(kvm_x86_hwapic_isr_update)(-1); } vcpu->arch.apic_arb_prio = 0; vcpu->arch.apic_attention = 0; kvm_recalculate_apic_map(vcpu->kvm); } /* *---------------------------------------------------------------------- * timer interface *---------------------------------------------------------------------- */ static bool lapic_is_periodic(struct kvm_lapic *apic) { return apic_lvtt_period(apic); } int apic_has_pending_timer(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; if (apic_enabled(apic) && apic_lvt_enabled(apic, APIC_LVTT)) return atomic_read(&apic->lapic_timer.pending); return 0; } int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type) { u32 reg = kvm_lapic_get_reg(apic, lvt_type); int vector, mode, trig_mode; if (kvm_apic_hw_enabled(apic) && !(reg & APIC_LVT_MASKED)) { vector = reg & APIC_VECTOR_MASK; mode = reg & APIC_MODE_MASK; trig_mode = reg & APIC_LVT_LEVEL_TRIGGER; return __apic_accept_irq(apic, mode, vector, 1, trig_mode, NULL); } return 0; } void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; if (apic) kvm_apic_local_deliver(apic, APIC_LVT0); } static const struct kvm_io_device_ops apic_mmio_ops = { .read = apic_mmio_read, .write = apic_mmio_write, }; static enum hrtimer_restart apic_timer_fn(struct hrtimer *data) { struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer); struct kvm_lapic *apic = container_of(ktimer, struct kvm_lapic, lapic_timer); apic_timer_expired(apic, true); if (lapic_is_periodic(apic)) { advance_periodic_target_expiration(apic); hrtimer_add_expires_ns(&ktimer->timer, ktimer->period); return HRTIMER_RESTART; } else return HRTIMER_NORESTART; } int kvm_create_lapic(struct kvm_vcpu *vcpu, int timer_advance_ns) { struct kvm_lapic *apic; ASSERT(vcpu != NULL); apic = kzalloc(sizeof(*apic), GFP_KERNEL_ACCOUNT); if (!apic) goto nomem; vcpu->arch.apic = apic; apic->regs = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); if (!apic->regs) { printk(KERN_ERR "malloc apic regs error for vcpu %x\n", vcpu->vcpu_id); goto nomem_free_apic; } apic->vcpu = vcpu; apic->nr_lvt_entries = kvm_apic_calc_nr_lvt_entries(vcpu); hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD); apic->lapic_timer.timer.function = apic_timer_fn; if (timer_advance_ns == -1) { apic->lapic_timer.timer_advance_ns = LAPIC_TIMER_ADVANCE_NS_INIT; lapic_timer_advance_dynamic = true; } else { apic->lapic_timer.timer_advance_ns = timer_advance_ns; lapic_timer_advance_dynamic = false; } /* * Stuff the APIC ENABLE bit in lieu of temporarily incrementing * apic_hw_disabled; the full RESET value is set by kvm_lapic_reset(). */ vcpu->arch.apic_base = MSR_IA32_APICBASE_ENABLE; static_branch_inc(&apic_sw_disabled.key); /* sw disabled at reset */ kvm_iodevice_init(&apic->dev, &apic_mmio_ops); return 0; nomem_free_apic: kfree(apic); vcpu->arch.apic = NULL; nomem: return -ENOMEM; } int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; u32 ppr; if (!kvm_apic_present(vcpu)) return -1; __apic_update_ppr(apic, &ppr); return apic_has_interrupt_for_ppr(apic, ppr); } EXPORT_SYMBOL_GPL(kvm_apic_has_interrupt); int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu) { u32 lvt0 = kvm_lapic_get_reg(vcpu->arch.apic, APIC_LVT0); if (!kvm_apic_hw_enabled(vcpu->arch.apic)) return 1; if ((lvt0 & APIC_LVT_MASKED) == 0 && GET_APIC_DELIVERY_MODE(lvt0) == APIC_MODE_EXTINT) return 1; return 0; } void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; if (atomic_read(&apic->lapic_timer.pending) > 0) { kvm_apic_inject_pending_timer_irqs(apic); atomic_set(&apic->lapic_timer.pending, 0); } } int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu) { int vector = kvm_apic_has_interrupt(vcpu); struct kvm_lapic *apic = vcpu->arch.apic; u32 ppr; if (vector == -1) return -1; /* * We get here even with APIC virtualization enabled, if doing * nested virtualization and L1 runs with the "acknowledge interrupt * on exit" mode. Then we cannot inject the interrupt via RVI, * because the process would deliver it through the IDT. */ apic_clear_irr(vector, apic); if (to_hv_vcpu(vcpu) && test_bit(vector, to_hv_synic(vcpu)->auto_eoi_bitmap)) { /* * For auto-EOI interrupts, there might be another pending * interrupt above PPR, so check whether to raise another * KVM_REQ_EVENT. */ apic_update_ppr(apic); } else { /* * For normal interrupts, PPR has been raised and there cannot * be a higher-priority pending interrupt---except if there was * a concurrent interrupt injection, but that would have * triggered KVM_REQ_EVENT already. */ apic_set_isr(vector, apic); __apic_update_ppr(apic, &ppr); } return vector; } static int kvm_apic_state_fixup(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s, bool set) { if (apic_x2apic_mode(vcpu->arch.apic)) { u32 *id = (u32 *)(s->regs + APIC_ID); u32 *ldr = (u32 *)(s->regs + APIC_LDR); u64 icr; if (vcpu->kvm->arch.x2apic_format) { if (*id != vcpu->vcpu_id) return -EINVAL; } else { if (set) *id >>= 24; else *id <<= 24; } /* * In x2APIC mode, the LDR is fixed and based on the id. And * ICR is internally a single 64-bit register, but needs to be * split to ICR+ICR2 in userspace for backwards compatibility. */ if (set) { *ldr = kvm_apic_calc_x2apic_ldr(*id); icr = __kvm_lapic_get_reg(s->regs, APIC_ICR) | (u64)__kvm_lapic_get_reg(s->regs, APIC_ICR2) << 32; __kvm_lapic_set_reg64(s->regs, APIC_ICR, icr); } else { icr = __kvm_lapic_get_reg64(s->regs, APIC_ICR); __kvm_lapic_set_reg(s->regs, APIC_ICR2, icr >> 32); } } return 0; } int kvm_apic_get_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) { memcpy(s->regs, vcpu->arch.apic->regs, sizeof(*s)); /* * Get calculated timer current count for remaining timer period (if * any) and store it in the returned register set. */ __kvm_lapic_set_reg(s->regs, APIC_TMCCT, __apic_read(vcpu->arch.apic, APIC_TMCCT)); return kvm_apic_state_fixup(vcpu, s, false); } int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) { struct kvm_lapic *apic = vcpu->arch.apic; int r; kvm_lapic_set_base(vcpu, vcpu->arch.apic_base); /* set SPIV separately to get count of SW disabled APICs right */ apic_set_spiv(apic, *((u32 *)(s->regs + APIC_SPIV))); r = kvm_apic_state_fixup(vcpu, s, true); if (r) { kvm_recalculate_apic_map(vcpu->kvm); return r; } memcpy(vcpu->arch.apic->regs, s->regs, sizeof(*s)); if (!apic_x2apic_mode(apic)) kvm_lapic_xapic_id_updated(apic); atomic_set_release(&apic->vcpu->kvm->arch.apic_map_dirty, DIRTY); kvm_recalculate_apic_map(vcpu->kvm); kvm_apic_set_version(vcpu); apic_update_ppr(apic); cancel_apic_timer(apic); apic->lapic_timer.expired_tscdeadline = 0; apic_update_lvtt(apic); apic_manage_nmi_watchdog(apic, kvm_lapic_get_reg(apic, APIC_LVT0)); update_divide_count(apic); __start_apic_timer(apic, APIC_TMCCT); kvm_lapic_set_reg(apic, APIC_TMCCT, 0); kvm_apic_update_apicv(vcpu); if (apic->apicv_active) { static_call_cond(kvm_x86_apicv_post_state_restore)(vcpu); static_call_cond(kvm_x86_hwapic_irr_update)(vcpu, apic_find_highest_irr(apic)); static_call_cond(kvm_x86_hwapic_isr_update)(apic_find_highest_isr(apic)); } kvm_make_request(KVM_REQ_EVENT, vcpu); if (ioapic_in_kernel(vcpu->kvm)) kvm_rtc_eoi_tracking_restore_one(vcpu); vcpu->arch.apic_arb_prio = 0; return 0; } void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu) { struct hrtimer *timer; if (!lapic_in_kernel(vcpu) || kvm_can_post_timer_interrupt(vcpu)) return; timer = &vcpu->arch.apic->lapic_timer.timer; if (hrtimer_cancel(timer)) hrtimer_start_expires(timer, HRTIMER_MODE_ABS_HARD); } /* * apic_sync_pv_eoi_from_guest - called on vmexit or cancel interrupt * * Detect whether guest triggered PV EOI since the * last entry. If yes, set EOI on guests's behalf. * Clear PV EOI in guest memory in any case. */ static void apic_sync_pv_eoi_from_guest(struct kvm_vcpu *vcpu, struct kvm_lapic *apic) { int vector; /* * PV EOI state is derived from KVM_APIC_PV_EOI_PENDING in host * and KVM_PV_EOI_ENABLED in guest memory as follows: * * KVM_APIC_PV_EOI_PENDING is unset: * -> host disabled PV EOI. * KVM_APIC_PV_EOI_PENDING is set, KVM_PV_EOI_ENABLED is set: * -> host enabled PV EOI, guest did not execute EOI yet. * KVM_APIC_PV_EOI_PENDING is set, KVM_PV_EOI_ENABLED is unset: * -> host enabled PV EOI, guest executed EOI. */ BUG_ON(!pv_eoi_enabled(vcpu)); if (pv_eoi_test_and_clr_pending(vcpu)) return; vector = apic_set_eoi(apic); trace_kvm_pv_eoi(apic, vector); } void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu) { u32 data; if (test_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention)) apic_sync_pv_eoi_from_guest(vcpu, vcpu->arch.apic); if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention)) return; if (kvm_read_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data, sizeof(u32))) return; apic_set_tpr(vcpu->arch.apic, data & 0xff); } /* * apic_sync_pv_eoi_to_guest - called before vmentry * * Detect whether it's safe to enable PV EOI and * if yes do so. */ static void apic_sync_pv_eoi_to_guest(struct kvm_vcpu *vcpu, struct kvm_lapic *apic) { if (!pv_eoi_enabled(vcpu) || /* IRR set or many bits in ISR: could be nested. */ apic->irr_pending || /* Cache not set: could be safe but we don't bother. */ apic->highest_isr_cache == -1 || /* Need EOI to update ioapic. */ kvm_ioapic_handles_vector(apic, apic->highest_isr_cache)) { /* * PV EOI was disabled by apic_sync_pv_eoi_from_guest * so we need not do anything here. */ return; } pv_eoi_set_pending(apic->vcpu); } void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu) { u32 data, tpr; int max_irr, max_isr; struct kvm_lapic *apic = vcpu->arch.apic; apic_sync_pv_eoi_to_guest(vcpu, apic); if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention)) return; tpr = kvm_lapic_get_reg(apic, APIC_TASKPRI) & 0xff; max_irr = apic_find_highest_irr(apic); if (max_irr < 0) max_irr = 0; max_isr = apic_find_highest_isr(apic); if (max_isr < 0) max_isr = 0; data = (tpr & 0xff) | ((max_isr & 0xf0) << 8) | (max_irr << 24); kvm_write_guest_cached(vcpu->kvm, &vcpu->arch.apic->vapic_cache, &data, sizeof(u32)); } int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr) { if (vapic_addr) { if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &vcpu->arch.apic->vapic_cache, vapic_addr, sizeof(u32))) return -EINVAL; __set_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention); } else { __clear_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention); } vcpu->arch.apic->vapic_addr = vapic_addr; return 0; } int kvm_x2apic_icr_write(struct kvm_lapic *apic, u64 data) { data &= ~APIC_ICR_BUSY; kvm_apic_send_ipi(apic, (u32)data, (u32)(data >> 32)); kvm_lapic_set_reg64(apic, APIC_ICR, data); trace_kvm_apic_write(APIC_ICR, data); return 0; } static int kvm_lapic_msr_read(struct kvm_lapic *apic, u32 reg, u64 *data) { u32 low; if (reg == APIC_ICR) { *data = kvm_lapic_get_reg64(apic, APIC_ICR); return 0; } if (kvm_lapic_reg_read(apic, reg, 4, &low)) return 1; *data = low; return 0; } static int kvm_lapic_msr_write(struct kvm_lapic *apic, u32 reg, u64 data) { /* * ICR is a 64-bit register in x2APIC mode (and Hyper-V PV vAPIC) and * can be written as such, all other registers remain accessible only * through 32-bit reads/writes. */ if (reg == APIC_ICR) return kvm_x2apic_icr_write(apic, data); /* Bits 63:32 are reserved in all other registers. */ if (data >> 32) return 1; return kvm_lapic_reg_write(apic, reg, (u32)data); } int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data) { struct kvm_lapic *apic = vcpu->arch.apic; u32 reg = (msr - APIC_BASE_MSR) << 4; if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic)) return 1; return kvm_lapic_msr_write(apic, reg, data); } int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data) { struct kvm_lapic *apic = vcpu->arch.apic; u32 reg = (msr - APIC_BASE_MSR) << 4; if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic)) return 1; if (reg == APIC_DFR) return 1; return kvm_lapic_msr_read(apic, reg, data); } int kvm_hv_vapic_msr_write(struct kvm_vcpu *vcpu, u32 reg, u64 data) { if (!lapic_in_kernel(vcpu)) return 1; return kvm_lapic_msr_write(vcpu->arch.apic, reg, data); } int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data) { if (!lapic_in_kernel(vcpu)) return 1; return kvm_lapic_msr_read(vcpu->arch.apic, reg, data); } int kvm_lapic_set_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len) { u64 addr = data & ~KVM_MSR_ENABLED; struct gfn_to_hva_cache *ghc = &vcpu->arch.pv_eoi.data; unsigned long new_len; int ret; if (!IS_ALIGNED(addr, 4)) return 1; if (data & KVM_MSR_ENABLED) { if (addr == ghc->gpa && len <= ghc->len) new_len = ghc->len; else new_len = len; ret = kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, addr, new_len); if (ret) return ret; } vcpu->arch.pv_eoi.msr_val = data; return 0; } int kvm_apic_accept_events(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; u8 sipi_vector; int r; if (!kvm_apic_has_pending_init_or_sipi(vcpu)) return 0; if (is_guest_mode(vcpu)) { r = kvm_check_nested_events(vcpu); if (r < 0) return r == -EBUSY ? 0 : r; /* * Continue processing INIT/SIPI even if a nested VM-Exit * occurred, e.g. pending SIPIs should be dropped if INIT+SIPI * are blocked as a result of transitioning to VMX root mode. */ } /* * INITs are blocked while CPU is in specific states (SMM, VMX root * mode, SVM with GIF=0), while SIPIs are dropped if the CPU isn't in * wait-for-SIPI (WFS). */ if (!kvm_apic_init_sipi_allowed(vcpu)) { WARN_ON_ONCE(vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED); clear_bit(KVM_APIC_SIPI, &apic->pending_events); return 0; } if (test_and_clear_bit(KVM_APIC_INIT, &apic->pending_events)) { kvm_vcpu_reset(vcpu, true); if (kvm_vcpu_is_bsp(apic->vcpu)) vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; else vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED; } if (test_and_clear_bit(KVM_APIC_SIPI, &apic->pending_events)) { if (vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) { /* evaluate pending_events before reading the vector */ smp_rmb(); sipi_vector = apic->sipi_vector; static_call(kvm_x86_vcpu_deliver_sipi_vector)(vcpu, sipi_vector); vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; } } return 0; } void kvm_lapic_exit(void) { static_key_deferred_flush(&apic_hw_disabled); WARN_ON(static_branch_unlikely(&apic_hw_disabled.key)); static_key_deferred_flush(&apic_sw_disabled); WARN_ON(static_branch_unlikely(&apic_sw_disabled.key)); }