diff options
| -rw-r--r-- | Documentation/virt/kvm/x86/errata.rst | 11 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm-x86-ops.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 52 | ||||
| -rw-r--r-- | arch/x86/kvm/lapic.c | 319 | ||||
| -rw-r--r-- | arch/x86/kvm/lapic.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/avic.c | 370 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 8 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 27 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 58 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 29 |
11 files changed, 523 insertions, 356 deletions
diff --git a/Documentation/virt/kvm/x86/errata.rst b/Documentation/virt/kvm/x86/errata.rst index 410e0aa63493..49a05f24747b 100644 --- a/Documentation/virt/kvm/x86/errata.rst +++ b/Documentation/virt/kvm/x86/errata.rst @@ -37,3 +37,14 @@ Nested virtualization features ------------------------------ TBD + +x2APIC +------ +When KVM_X2APIC_API_USE_32BIT_IDS is enabled, KVM activates a hack/quirk that +allows sending events to a single vCPU using its x2APIC ID even if the target +vCPU has legacy xAPIC enabled, e.g. to bring up hotplugged vCPUs via INIT-SIPI +on VMs with > 255 vCPUs. A side effect of the quirk is that, if multiple vCPUs +have the same physical APIC ID, KVM will deliver events targeting that APIC ID +only to the vCPU with the lowest vCPU ID. If KVM_X2APIC_API_USE_32BIT_IDS is +not enabled, KVM follows x86 architecture when processing interrupts (all vCPUs +matching the target APIC ID receive the interrupt). diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index dba2909e5ae2..8dc345cc6318 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -77,7 +77,6 @@ KVM_X86_OP(set_nmi_mask) KVM_X86_OP(enable_nmi_window) KVM_X86_OP(enable_irq_window) KVM_X86_OP_OPTIONAL(update_cr8_intercept) -KVM_X86_OP(check_apicv_inhibit_reasons) KVM_X86_OP(refresh_apicv_exec_ctrl) KVM_X86_OP_OPTIONAL(hwapic_irr_update) KVM_X86_OP_OPTIONAL(hwapic_isr_update) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 8d0a0a7c34fc..4d2bc08794e4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1022,19 +1022,30 @@ struct kvm_arch_memory_slot { }; /* - * We use as the mode the number of bits allocated in the LDR for the - * logical processor ID. It happens that these are all powers of two. - * This makes it is very easy to detect cases where the APICs are - * configured for multiple modes; in that case, we cannot use the map and - * hence cannot use kvm_irq_delivery_to_apic_fast either. + * Track the mode of the optimized logical map, as the rules for decoding the + * destination vary per mode. Enabling the optimized logical map requires all + * software-enabled local APIs to be in the same mode, each addressable APIC to + * be mapped to only one MDA, and each MDA to map to at most one APIC. */ -#define KVM_APIC_MODE_XAPIC_CLUSTER 4 -#define KVM_APIC_MODE_XAPIC_FLAT 8 -#define KVM_APIC_MODE_X2APIC 16 +enum kvm_apic_logical_mode { + /* All local APICs are software disabled. */ + KVM_APIC_MODE_SW_DISABLED, + /* All software enabled local APICs in xAPIC cluster addressing mode. */ + KVM_APIC_MODE_XAPIC_CLUSTER, + /* All software enabled local APICs in xAPIC flat addressing mode. */ + KVM_APIC_MODE_XAPIC_FLAT, + /* All software enabled local APICs in x2APIC mode. */ + KVM_APIC_MODE_X2APIC, + /* + * Optimized map disabled, e.g. not all local APICs in the same logical + * mode, same logical ID assigned to multiple APICs, etc. + */ + KVM_APIC_MODE_MAP_DISABLED, +}; struct kvm_apic_map { struct rcu_head rcu; - u8 mode; + enum kvm_apic_logical_mode logical_mode; u32 max_apic_id; union { struct kvm_lapic *xapic_flat_map[8]; @@ -1165,6 +1176,12 @@ enum kvm_apicv_inhibit { APICV_INHIBIT_REASON_BLOCKIRQ, /* + * APICv is disabled because not all vCPUs have a 1:1 mapping between + * APIC ID and vCPU, _and_ KVM is not applying its x2APIC hotplug hack. + */ + APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED, + + /* * For simplicity, the APIC acceleration is inhibited * first time either APIC ID or APIC base are changed by the guest * from their reset values. @@ -1202,6 +1219,12 @@ enum kvm_apicv_inhibit { * AVIC is disabled because SEV doesn't support it. */ APICV_INHIBIT_REASON_SEV, + + /* + * AVIC is disabled because not all vCPUs with a valid LDR have a 1:1 + * mapping between logical ID and vCPU. + */ + APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED, }; struct kvm_arch { @@ -1250,10 +1273,11 @@ struct kvm_arch { struct kvm_apic_map __rcu *apic_map; atomic_t apic_map_dirty; - /* Protects apic_access_memslot_enabled and apicv_inhibit_reasons */ - struct rw_semaphore apicv_update_lock; - bool apic_access_memslot_enabled; + bool apic_access_memslot_inhibited; + + /* Protects apicv_inhibit_reasons */ + struct rw_semaphore apicv_update_lock; unsigned long apicv_inhibit_reasons; gpa_t wall_clock; @@ -1602,6 +1626,8 @@ struct kvm_x86_ops { void (*enable_irq_window)(struct kvm_vcpu *vcpu); void (*update_cr8_intercept)(struct kvm_vcpu *vcpu, int tpr, int irr); bool (*check_apicv_inhibit_reasons)(enum kvm_apicv_inhibit reason); + const unsigned long required_apicv_inhibits; + bool allow_apicv_in_x2apic_without_x2apic_virtualization; void (*refresh_apicv_exec_ctrl)(struct kvm_vcpu *vcpu); void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr); void (*hwapic_isr_update)(int isr); @@ -1976,7 +2002,7 @@ gpa_t kvm_mmu_gva_to_gpa_system(struct kvm_vcpu *vcpu, gva_t gva, bool kvm_apicv_activated(struct kvm *kvm); bool kvm_vcpu_apicv_activated(struct kvm_vcpu *vcpu); -void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu); +void __kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu); void __kvm_set_or_clear_apicv_inhibit(struct kvm *kvm, enum kvm_apicv_inhibit reason, bool set); void kvm_set_or_clear_apicv_inhibit(struct kvm *kvm, diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index cfaf1d8c64ca..7cf4eebc9bcc 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -167,9 +167,19 @@ 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 u32 kvm_apic_calc_x2apic_ldr(u32 id) +{ + return ((id >> 4) << 16) | (1 << (id & 0xf)); +} + 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) { + switch (map->logical_mode) { + case KVM_APIC_MODE_SW_DISABLED: + /* Arbitrarily use the flat map so that @cluster isn't NULL. */ + *cluster = map->xapic_flat_map; + *mask = 0; + return true; case KVM_APIC_MODE_X2APIC: { u32 offset = (dest_id >> 16) * 16; u32 max_apic_id = map->max_apic_id; @@ -194,8 +204,10 @@ static inline bool kvm_apic_map_get_logical_dest(struct kvm_apic_map *map, *cluster = map->xapic_cluster_map[(dest_id >> 4) & 0xf]; *mask = dest_id & 0xf; return true; + case KVM_APIC_MODE_MAP_DISABLED: + return false; default: - /* Not optimized. */ + WARN_ON_ONCE(1); return false; } } @@ -207,6 +219,134 @@ static void kvm_apic_map_free(struct rcu_head *rcu) kvfree(map); } +static int kvm_recalculate_phys_map(struct kvm_apic_map *new, + struct kvm_vcpu *vcpu, + bool *xapic_id_mismatch) +{ + struct kvm_lapic *apic = vcpu->arch.apic; + u32 x2apic_id = kvm_x2apic_id(apic); + u32 xapic_id = kvm_xapic_id(apic); + u32 physical_id; + + /* + * Deliberately truncate the vCPU ID when detecting a mismatched APIC + * ID to avoid false positives if the vCPU ID, i.e. x2APIC ID, is a + * 32-bit value. Any unwanted aliasing due to truncation results will + * be detected below. + */ + if (!apic_x2apic_mode(apic) && xapic_id != (u8)vcpu->vcpu_id) + *xapic_id_mismatch = true; + + /* + * Apply KVM's hotplug hack if userspace has enable 32-bit APIC IDs. + * Allow sending events to vCPUs by their x2APIC ID even if the target + * vCPU is in legacy xAPIC mode, and silently ignore aliased xAPIC IDs + * (the x2APIC ID is truncated to 8 bits, causing IDs > 0xff to wrap + * and collide). + * + * Honor the architectural (and KVM's non-optimized) behavior if + * userspace has not enabled 32-bit x2APIC IDs. Each APIC is supposed + * to process messages independently. If multiple vCPUs have the same + * effective APIC ID, e.g. due to the x2APIC wrap or because the guest + * manually modified its xAPIC IDs, events targeting that ID are + * supposed to be recognized by all vCPUs with said ID. + */ + if (vcpu->kvm->arch.x2apic_format) { + /* See also 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; + + if (!apic_x2apic_mode(apic) && !new->phys_map[xapic_id]) + new->phys_map[xapic_id] = apic; + } else { + /* + * Disable the optimized map if the physical APIC ID is already + * mapped, i.e. is aliased to multiple vCPUs. The optimized + * map requires a strict 1:1 mapping between IDs and vCPUs. + */ + if (apic_x2apic_mode(apic)) + physical_id = x2apic_id; + else + physical_id = xapic_id; + + if (new->phys_map[physical_id]) + return -EINVAL; + + new->phys_map[physical_id] = apic; + } + + return 0; +} + +static void kvm_recalculate_logical_map(struct kvm_apic_map *new, + struct kvm_vcpu *vcpu) +{ + struct kvm_lapic *apic = vcpu->arch.apic; + enum kvm_apic_logical_mode logical_mode; + struct kvm_lapic **cluster; + u16 mask; + u32 ldr; + + if (new->logical_mode == KVM_APIC_MODE_MAP_DISABLED) + return; + + if (!kvm_apic_sw_enabled(apic)) + return; + + ldr = kvm_lapic_get_reg(apic, APIC_LDR); + if (!ldr) + return; + + if (apic_x2apic_mode(apic)) { + logical_mode = KVM_APIC_MODE_X2APIC; + } else { + ldr = GET_APIC_LOGICAL_ID(ldr); + if (kvm_lapic_get_reg(apic, APIC_DFR) == APIC_DFR_FLAT) + logical_mode = KVM_APIC_MODE_XAPIC_FLAT; + else + logical_mode = KVM_APIC_MODE_XAPIC_CLUSTER; + } + + /* + * To optimize logical mode delivery, all software-enabled APICs must + * be configured for the same mode. + */ + if (new->logical_mode == KVM_APIC_MODE_SW_DISABLED) { + new->logical_mode = logical_mode; + } else if (new->logical_mode != logical_mode) { + new->logical_mode = KVM_APIC_MODE_MAP_DISABLED; + return; + } + + /* + * In x2APIC mode, the LDR is read-only and derived directly from the + * x2APIC ID, thus is guaranteed to be addressable. KVM reuses + * kvm_apic_map.phys_map to optimize logical mode x2APIC interrupts by + * reversing the LDR calculation to get cluster of APICs, i.e. no + * additional work is required. + */ + if (apic_x2apic_mode(apic)) { + WARN_ON_ONCE(ldr != kvm_apic_calc_x2apic_ldr(kvm_x2apic_id(apic))); + return; + } + + if (WARN_ON_ONCE(!kvm_apic_map_get_logical_dest(new, ldr, + &cluster, &mask))) { + new->logical_mode = KVM_APIC_MODE_MAP_DISABLED; + return; + } + + if (!mask) + return; + + ldr = ffs(mask) - 1; + if (!is_power_of_2(mask) || cluster[ldr]) + new->logical_mode = KVM_APIC_MODE_MAP_DISABLED; + else + cluster[ldr] = apic; +} + /* * CLEAN -> DIRTY and UPDATE_IN_PROGRESS -> DIRTY changes happen without a lock. * @@ -225,6 +365,7 @@ void kvm_recalculate_apic_map(struct kvm *kvm) struct kvm_vcpu *vcpu; unsigned long i; u32 max_id = 255; /* enough space for any xAPIC ID */ + bool xapic_id_mismatch = false; /* Read kvm->arch.apic_map_dirty before kvm->arch.apic_map. */ if (atomic_read_acquire(&kvm->arch.apic_map_dirty) == CLEAN) @@ -257,54 +398,41 @@ void kvm_recalculate_apic_map(struct kvm *kvm) goto out; new->max_apic_id = max_id; + new->logical_mode = KVM_APIC_MODE_SW_DISABLED; 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_recalculate_phys_map(new, vcpu, &xapic_id_mismatch)) { + kvfree(new); + new = NULL; + goto out; } - if (!kvm_apic_map_get_logical_dest(new, ldr, &cluster, &mask)) - continue; - - if (mask) - cluster[ffs(mask) - 1] = apic; + kvm_recalculate_logical_map(new, vcpu); } out: + /* + * The optimized map is effectively KVM's internal version of APICv, + * and all unwanted aliasing that results in disabling the optimized + * map also applies to APICv. + */ + if (!new) + kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED); + else + kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_PHYSICAL_ID_ALIASED); + + if (!new || new->logical_mode == KVM_APIC_MODE_MAP_DISABLED) + kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED); + else + kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_LOGICAL_ID_ALIASED); + + if (xapic_id_mismatch) + kvm_set_apicv_inhibit(kvm, APICV_INHIBIT_REASON_APIC_ID_MODIFIED); + else + kvm_clear_apicv_inhibit(kvm, APICV_INHIBIT_REASON_APIC_ID_MODIFIED); + old = rcu_dereference_protected(kvm->arch.apic_map, lockdep_is_held(&kvm->arch.apic_map_lock)); rcu_assign_pointer(kvm->arch.apic_map, new); @@ -361,11 +489,6 @@ static inline void kvm_apic_set_dfr(struct kvm_lapic *apic, u32 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); @@ -951,7 +1074,7 @@ static bool kvm_apic_is_broadcast_dest(struct kvm *kvm, struct kvm_lapic **src, { if (kvm->arch.x2apic_broadcast_quirk_disabled) { if ((irq->dest_id == APIC_BROADCAST && - map->mode != KVM_APIC_MODE_X2APIC)) + map->logical_mode != KVM_APIC_MODE_X2APIC)) return true; if (irq->dest_id == X2APIC_BROADCAST) return true; @@ -2068,19 +2191,6 @@ static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val) } } -static void kvm_lapic_xapic_id_updated(struct kvm_lapic *apic) -{ - struct kvm *kvm = apic->vcpu->kvm; - - if (KVM_BUG_ON(apic_x2apic_mode(apic), kvm)) - return; - - if (kvm_xapic_id(apic) == 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) @@ -2101,7 +2211,6 @@ static int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) 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; } @@ -2284,23 +2393,18 @@ void kvm_apic_write_nodecode(struct kvm_vcpu *vcpu, u32 offset) struct kvm_lapic *apic = vcpu->arch.apic; u64 val; - if (apic_x2apic_mode(apic)) { - if (KVM_BUG_ON(kvm_lapic_msr_read(apic, offset, &val), vcpu->kvm)) - return; - } else { - val = kvm_lapic_get_reg(apic, offset); - } - /* * 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); } } @@ -2398,7 +2502,7 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id); if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) { - kvm_vcpu_update_apicv(vcpu); + kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu); static_call_cond(kvm_x86_set_virtual_apic_mode)(vcpu); } @@ -2429,6 +2533,78 @@ void kvm_apic_update_apicv(struct kvm_vcpu *vcpu) */ apic->isr_count = count_vectors(apic->regs + APIC_ISR); } + apic->highest_isr_cache = -1; +} + +int kvm_alloc_apic_access_page(struct kvm *kvm) +{ + struct page *page; + void __user *hva; + int ret = 0; + + mutex_lock(&kvm->slots_lock); + if (kvm->arch.apic_access_memslot_enabled || + kvm->arch.apic_access_memslot_inhibited) + goto out; + + hva = __x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, + APIC_DEFAULT_PHYS_BASE, PAGE_SIZE); + if (IS_ERR(hva)) { + ret = PTR_ERR(hva); + goto out; + } + + page = gfn_to_page(kvm, APIC_DEFAULT_PHYS_BASE >> PAGE_SHIFT); + if (is_error_page(page)) { + ret = -EFAULT; + goto out; + } + + /* + * Do not pin the page in memory, so that memory hot-unplug + * is able to migrate it. + */ + put_page(page); + kvm->arch.apic_access_memslot_enabled = true; +out: + mutex_unlock(&kvm->slots_lock); + return ret; +} +EXPORT_SYMBOL_GPL(kvm_alloc_apic_access_page); + +void kvm_inhibit_apic_access_page(struct kvm_vcpu *vcpu) +{ + struct kvm *kvm = vcpu->kvm; + + if (!kvm->arch.apic_access_memslot_enabled) + return; + + kvm_vcpu_srcu_read_unlock(vcpu); + + mutex_lock(&kvm->slots_lock); + + if (kvm->arch.apic_access_memslot_enabled) { + __x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, 0, 0); + /* + * Clear "enabled" after the memslot is deleted so that a + * different vCPU doesn't get a false negative when checking + * the flag out of slots_lock. No additional memory barrier is + * needed as modifying memslots requires waiting other vCPUs to + * drop SRCU (see above), and false positives are ok as the + * flag is rechecked after acquiring slots_lock. + */ + kvm->arch.apic_access_memslot_enabled = false; + + /* + * Mark the memslot as inhibited to prevent reallocating the + * memslot during vCPU creation, e.g. if a vCPU is hotplugged. + */ + kvm->arch.apic_access_memslot_inhibited = true; + } + + mutex_unlock(&kvm->slots_lock); + + kvm_vcpu_srcu_read_lock(vcpu); } void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) @@ -2484,7 +2660,6 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) kvm_lapic_set_reg(apic, APIC_TMR + 0x10 * i, 0); } kvm_apic_update_apicv(vcpu); - apic->highest_isr_cache = -1; update_divide_count(apic); atomic_set(&apic->lapic_timer.pending, 0); @@ -2756,9 +2931,6 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) } 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); @@ -2772,7 +2944,6 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) __start_apic_timer(apic, APIC_TMCCT); kvm_lapic_set_reg(apic, APIC_TMCCT, 0); kvm_apic_update_apicv(vcpu); - apic->highest_isr_cache = -1; 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)); diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index 58c3242fcc7a..df316ede7546 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -112,6 +112,8 @@ int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq, struct dest_map *dest_map); int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type); void kvm_apic_update_apicv(struct kvm_vcpu *vcpu); +int kvm_alloc_apic_access_page(struct kvm *kvm); +void kvm_inhibit_apic_access_page(struct kvm_vcpu *vcpu); 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); diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index f52f5e0dd465..b3928150a37c 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -53,7 +53,7 @@ static DEFINE_HASHTABLE(svm_vm_data_hash, SVM_VM_DATA_HASH_BITS); static u32 next_vm_id = 0; static bool next_vm_id_wrapped = 0; static DEFINE_SPINLOCK(svm_vm_data_hash_lock); -enum avic_modes avic_mode; +bool x2avic_enabled; /* * This is a wrapper of struct amd_iommu_ir_data. @@ -72,20 +72,25 @@ static void avic_activate_vmcb(struct vcpu_svm *svm) vmcb->control.int_ctl |= AVIC_ENABLE_MASK; - /* Note: - * KVM can support hybrid-AVIC mode, where KVM emulates x2APIC - * MSR accesses, while interrupt injection to a running vCPU - * can be achieved using AVIC doorbell. The AVIC hardware still - * accelerate MMIO accesses, but this does not cause any harm - * as the guest is not supposed to access xAPIC mmio when uses x2APIC. + /* + * Note: KVM supports hybrid-AVIC mode, where KVM emulates x2APIC MSR + * accesses, while interrupt injection to a running vCPU can be + * achieved using AVIC doorbell. KVM disables the APIC access page + * (deletes the memslot) if any vCPU has x2APIC enabled, thus enabling + * AVIC in hybrid mode activates only the doorbell mechanism. */ - if (apic_x2apic_mode(svm->vcpu.arch.apic) && - avic_mode == AVIC_MODE_X2) { + if (x2avic_enabled && apic_x2apic_mode(svm->vcpu.arch.apic)) { vmcb->control.int_ctl |= X2APIC_MODE_MASK; vmcb->control.avic_physical_id |= X2AVIC_MAX_PHYSICAL_ID; /* Disabling MSR intercept for x2APIC registers */ svm_set_x2apic_msr_interception(svm, false); } else { + /* + * Flush the TLB, the guest may have inserted a non-APIC + * mapping into the TLB while AVIC was disabled. + */ + kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, &svm->vcpu); + /* For xAVIC and hybrid-xAVIC modes */ vmcb->control.avic_physical_id |= AVIC_MAX_PHYSICAL_ID; /* Enabling MSR intercept for x2APIC registers */ @@ -241,8 +246,8 @@ static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu, u64 *avic_physical_id_table; struct kvm_svm *kvm_svm = to_kvm_svm(vcpu->kvm); - if ((avic_mode == AVIC_MODE_X1 && index > AVIC_MAX_PHYSICAL_ID) || - (avic_mode == AVIC_MODE_X2 && index > X2AVIC_MAX_PHYSICAL_ID)) + if ((!x2avic_enabled && index > AVIC_MAX_PHYSICAL_ID) || + (index > X2AVIC_MAX_PHYSICAL_ID)) return NULL; avic_physical_id_table = page_address(kvm_svm->avic_physical_id_table_page); @@ -250,47 +255,14 @@ static u64 *avic_get_physical_id_entry(struct kvm_vcpu *vcpu, return &avic_physical_id_table[index]; } -/* - * Note: - * AVIC hardware walks the nested page table to check permissions, - * but does not use the SPA address specified in the leaf page - * table entry since it uses address in the AVIC_BACKING_PAGE pointer - * field of the VMCB. Therefore, we set up the - * APIC_ACCESS_PAGE_PRIVATE_MEMSLOT (4KB) here. - */ -static int avic_alloc_access_page(struct kvm *kvm) -{ - void __user *ret; - int r = 0; - - mutex_lock(&kvm->slots_lock); - - if (kvm->arch.apic_access_memslot_enabled) - goto out; - - ret = __x86_set_memory_region(kvm, - APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, - APIC_DEFAULT_PHYS_BASE, - PAGE_SIZE); - if (IS_ERR(ret)) { - r = PTR_ERR(ret); - goto out; - } - - kvm->arch.apic_access_memslot_enabled = true; -out: - mutex_unlock(&kvm->slots_lock); - return r; -} - static int avic_init_backing_page(struct kvm_vcpu *vcpu) { u64 *entry, new_entry; int id = vcpu->vcpu_id; struct vcpu_svm *svm = to_svm(vcpu); - if ((avic_mode == AVIC_MODE_X1 && id > AVIC_MAX_PHYSICAL_ID) || - (avic_mode == AVIC_MODE_X2 && id > X2AVIC_MAX_PHYSICAL_ID)) + if ((!x2avic_enabled && id > AVIC_MAX_PHYSICAL_ID) || + (id > X2AVIC_MAX_PHYSICAL_ID)) return -EINVAL; if (!vcpu->arch.apic->regs) @@ -299,7 +271,13 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu) if (kvm_apicv_activated(vcpu->kvm)) { int ret; - ret = avic_alloc_access_page(vcpu->kvm); + /* + * Note, AVIC hardware walks the nested page table to check + * permissions, but does not use the SPA address specified in + * the leaf SPTE since it uses address in the AVIC_BACKING_PAGE + * pointer field of the VMCB. + */ + ret = kvm_alloc_apic_access_page(vcpu->kvm); if (ret) return ret; } @@ -339,6 +317,60 @@ void avic_ring_doorbell(struct kvm_vcpu *vcpu) put_cpu(); } + +static void avic_kick_vcpu(struct kvm_vcpu *vcpu, u32 icrl) +{ + vcpu->arch.apic->irr_pending = true; + svm_complete_interrupt_delivery(vcpu, + icrl & APIC_MODE_MASK, + icrl & APIC_INT_LEVELTRIG, + icrl & APIC_VECTOR_MASK); +} + +static void avic_kick_vcpu_by_physical_id(struct kvm *kvm, u32 physical_id, + u32 icrl) +{ + /* + * KVM inhibits AVIC if any vCPU ID diverges from the vCPUs APIC ID, + * i.e. APIC ID == vCPU ID. + */ + struct kvm_vcpu *target_vcpu = kvm_get_vcpu_by_id(kvm, physical_id); + + /* Once again, nothing to do if the target vCPU doesn't exist. */ + if (unlikely(!target_vcpu)) + return; + + avic_kick_vcpu(target_vcpu, icrl); +} + +static void avic_kick_vcpu_by_logical_id(struct kvm *kvm, u32 *avic_logical_id_table, + u32 logid_index, u32 icrl) +{ + u32 physical_id; + + if (avic_logical_id_table) { + u32 logid_entry = avic_logical_id_table[logid_index]; + + /* Nothing to do if the logical destination is invalid. */ + if (unlikely(!(logid_entry & AVIC_LOGICAL_ID_ENTRY_VALID_MASK))) + return; + + physical_id = logid_entry & + AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK; + } else { + /* + * For x2APIC, the logical APIC ID is a read-only value that is + * derived from the x2APIC ID, thus the x2APIC ID can be found + * by reversing the calculation (stored in logid_index). Note, + * bits 31:20 of the x2APIC ID aren't propagated to the logical + * ID, but KVM limits the x2APIC ID limited to KVM_MAX_VCPU_IDS. + */ + physical_id = logid_index; + } + + avic_kick_vcpu_by_physical_id(kvm, physical_id, icrl); +} + /* * A fast-path version of avic_kick_target_vcpus(), which attempts to match * destination APIC ID to vCPU without looping through all vCPUs. @@ -346,11 +378,10 @@ void avic_ring_doorbell(struct kvm_vcpu *vcpu) static int avic_kick_target_vcpus_fast(struct kvm *kvm, struct kvm_lapic *source, u32 icrl, u32 icrh, u32 index) { - u32 l1_physical_id, dest; - struct kvm_vcpu *target_vcpu; int dest_mode = icrl & APIC_DEST_MASK; int shorthand = icrl & APIC_SHORT_MASK; struct kvm_svm *kvm_svm = to_kvm_svm(kvm); + u32 dest; if (shorthand != APIC_DEST_NOSHORT) return -EINVAL; @@ -367,18 +398,18 @@ static int avic_kick_target_vcpus_fast(struct kvm *kvm, struct kvm_lapic *source if (!apic_x2apic_mode(source) && dest == APIC_BROADCAST) return -EINVAL; - l1_physical_id = dest; - - if (WARN_ON_ONCE(l1_physical_id != index)) + if (WARN_ON_ONCE(dest != index)) return -EINVAL; + avic_kick_vcpu_by_physical_id(kvm, dest, icrl); } else { - u32 bitmap, cluster; - int logid_index; + u32 *avic_logical_id_table; + unsigned long bitmap, i; + u32 cluster; if (apic_x2apic_mode(source)) { /* 16 bit dest mask, 16 bit cluster id */ - bitmap = dest & 0xFFFF0000; + bitmap = dest & 0xFFFF; cluster = (dest >> 16) << 4; } else if (kvm_lapic_get_reg(source, APIC_DFR) == APIC_DFR_FLAT) { /* 8 bit dest mask*/ @@ -390,67 +421,32 @@ static int avic_kick_target_vcpus_fast(struct kvm *kvm, struct kvm_lapic *source cluster = (dest >> 4) << 2; } + /* Nothing to do if there are no destinations in the cluster. */ if (unlikely(!bitmap)) - /* guest bug: nobody to send the logical interrupt to */ return 0; - if (!is_power_of_2(bitmap)) - /* multiple logical destinations, use slow path */ - return -EINVAL; - - logid_index = cluster + __ffs(bitmap); - - if (!apic_x2apic_mode(source)) { - u32 *avic_logical_id_table = - page_address(kvm_svm->avic_logical_id_table_page); - - u32 logid_entry = avic_logical_id_table[logid_index]; - - if (WARN_ON_ONCE(index != logid_index)) - return -EINVAL; - - /* guest bug: non existing/reserved logical destination */ - if (unlikely(!(logid_entry & AVIC_LOGICAL_ID_ENTRY_VALID_MASK))) - return 0; - - l1_physical_id = logid_entry & - AVIC_LOGICAL_ID_ENTRY_GUEST_PHYSICAL_ID_MASK; - } else { - /* - * For x2APIC logical mode, cannot leverage the index. - * Instead, calculate physical ID from logical ID in ICRH. - */ - int cluster = (icrh & 0xffff0000) >> 16; - int apic = ffs(icrh & 0xffff) - 1; - - /* - * If the x2APIC logical ID sub-field (i.e. icrh[15:0]) - * contains anything but a single bit, we cannot use the - * fast path, because it is limited to a single vCPU. - */ - if (apic < 0 || icrh != (1 << apic)) - return -EINVAL; + if (apic_x2apic_mode(source)) + avic_logical_id_table = NULL; + else + avic_logical_id_table = page_address(kvm_svm->avic_logical_id_table_page); - l1_physical_id = (cluster << 4) + apic; - } + /* + * AVIC is inhibited if vCPUs aren't mapped 1:1 with logical + * IDs, thus each bit in the destination is guaranteed to map + * to at most one vCPU. + */ + for_each_set_bit(i, &bitmap, 16) + avic_kick_vcpu_by_logical_id(kvm, avic_logical_id_table, + cluster + i, icrl); } - target_vcpu = kvm_get_vcpu_by_id(kvm, l1_physical_id); - if (unlikely(!target_vcpu)) - /* guest bug: non existing vCPU is a target of this IPI*/ - return 0; - - target_vcpu->arch.apic->irr_pending = true; - svm_complete_interrupt_delivery(target_vcpu, - icrl & APIC_MODE_MASK, - icrl & APIC_INT_LEVELTRIG, - icrl & APIC_VECTOR_MASK); return 0; } static void avic_kick_target_vcpus(struct kvm *kvm, struct kvm_lapic *source, u32 icrl, u32 icrh, u32 index) { + u32 dest = apic_x2apic_mode(source) ? icrh : GET_XAPIC_DEST_FIELD(icrh); unsigned long i; struct kvm_vcpu *vcpu; @@ -466,21 +462,9 @@ static void avic_kick_target_vcpus(struct kvm *kvm, struct kvm_lapic *source, * since entered the guest will have processed pending IRQs at VMRUN. */ kvm_for_each_vcpu(i, vcpu, kvm) { - u32 dest; - - if (apic_x2apic_mode(vcpu->arch.apic)) - dest = icrh; - else - dest = GET_XAPIC_DEST_FIELD(icrh); - if (kvm_apic_match_dest(vcpu, source, icrl & APIC_SHORT_MASK, - dest, icrl & APIC_DEST_MASK)) { - vcpu->arch.apic->irr_pending = true; - svm_complete_interrupt_delivery(vcpu, - icrl & APIC_MODE_MASK, - icrl & APIC_INT_LEVELTRIG, - icrl & APIC_VECTOR_MASK); - } + dest, icrl & APIC_DEST_MASK)) + avic_kick_vcpu(vcpu, icrl); } } @@ -496,14 +480,18 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu) trace_kvm_avic_incomplete_ipi(vcpu->vcpu_id, icrh, icrl, id, index); switch (id) { + case AVIC_IPI_FAILURE_INVALID_TARGET: case AVIC_IPI_FAILURE_INVALID_INT_TYPE: /* * Emulate IPIs that are not handled by AVIC hardware, which - * only virtualizes Fixed, Edge-Triggered INTRs. The exit is - * a trap, e.g. ICR holds the correct value and RIP has been - * advanced, KVM is responsible only for emulating the IPI. - * Sadly, hardware may sometimes leave the BUSY flag set, in - * which case KVM needs to emulate the ICR write as well in + * only virtualizes Fixed, Edge-Triggered INTRs, and falls over + * if _any_ targets are invalid, e.g. if the logical mode mask + * is a superset of running vCPUs. + * + * The exit is a trap, e.g. ICR holds the correct value and RIP + * has been advanced, KVM is responsible only for emulating the + * IPI. Sadly, hardware may sometimes leave the BUSY flag set, + * in which case KVM needs to emulate the ICR write as well in * order to clear the BUSY flag. */ if (icrl & APIC_ICR_BUSY) @@ -519,8 +507,6 @@ int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu) |