diff options
Diffstat (limited to 'arch/x86/kvm/lapic.c')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 1554 |
1 files changed, 1070 insertions, 484 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index ba5a27879f1d..1597dd0b0cc6 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -15,6 +15,7 @@ * * Based on Xen 3.1 code, Copyright (c) 2004, Intel Corporation. */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kvm_host.h> #include <linux/kvm.h> @@ -26,7 +27,9 @@ #include <linux/export.h> #include <linux/math64.h> #include <linux/slab.h> +#include <asm/apic.h> #include <asm/processor.h> +#include <asm/mce.h> #include <asm/msr.h> #include <asm/page.h> #include <asm/current.h> @@ -39,8 +42,10 @@ #include "ioapic.h" #include "trace.h" #include "x86.h" +#include "xen.h" #include "cpuid.h" #include "hyperv.h" +#include "smm.h" #ifndef CONFIG_X86_64 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y)) @@ -48,19 +53,21 @@ #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 | ((KVM_APIC_LVT_NUM - 1) << 16)) +#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; +/* + * Enable local APIC timer advancement (tscdeadline mode only) with adaptive + * tuning. When enabled, KVM programs the host timer event to fire early, i.e. + * before the deadline expires, to account for the delay between taking the + * VM-Exit (to inject the guest event) and the subsequent VM-Enter to resume + * the guest, i.e. so that the interrupt arrives in the guest with minimal + * latency relative to the deadline programmed by the guest. + */ +static bool lapic_timer_advance __read_mostly = true; +module_param(lapic_timer_advance, bool, 0444); + #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 @@ -68,29 +75,39 @@ static bool lapic_timer_advance_dynamic __read_mostly; /* step-by-step approximation to mitigate fluctuation */ #define LAPIC_TIMER_ADVANCE_ADJUST_STEP 8 -static inline int apic_test_vector(int vec, void *bitmap) +static bool __read_mostly vector_hashing_enabled = true; +module_param_named(vector_hashing, vector_hashing_enabled, bool, 0444); + +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(struct kvm_lapic *apic, int reg_off, u32 val) { - return test_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); + apic_set_reg(apic->regs, reg_off, val); } -bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector) +static __always_inline u64 kvm_lapic_get_reg64(struct kvm_lapic *apic, int reg) { - struct kvm_lapic *apic = vcpu->arch.apic; - - return apic_test_vector(vector, apic->regs + APIC_ISR) || - apic_test_vector(vector, apic->regs + APIC_IRR); + return apic_get_reg64(apic->regs, reg); } -static inline int __apic_test_and_set_vector(int vec, void *bitmap) +static __always_inline void kvm_lapic_set_reg64(struct kvm_lapic *apic, + int reg, u64 val) { - return __test_and_set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); + apic_set_reg64(apic->regs, reg, val); } -static inline int __apic_test_and_clear_vector(int vec, void *bitmap) +bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector) { - return __test_and_clear_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); + struct kvm_lapic *apic = vcpu->arch.apic; + + return apic_test_vector(vector, apic->regs + APIC_ISR) || + apic_test_vector(vector, apic->regs + APIC_IRR); } +__read_mostly DEFINE_STATIC_KEY_FALSE(kvm_has_noapic_vcpu); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_has_noapic_vcpu); + __read_mostly DEFINE_STATIC_KEY_DEFERRED_FALSE(apic_hw_disabled, HZ); __read_mostly DEFINE_STATIC_KEY_DEFERRED_FALSE(apic_sw_disabled, HZ); @@ -113,25 +130,35 @@ static inline u32 kvm_x2apic_id(struct kvm_lapic *apic) static bool kvm_can_post_timer_interrupt(struct kvm_vcpu *vcpu) { - return pi_inject_timer && kvm_vcpu_apicv_active(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) +static 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 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; @@ -156,17 +183,154 @@ 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; } } -static void kvm_apic_map_free(struct rcu_head *rcu) +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; + + /* + * For simplicity, KVM always allocates enough space for all possible + * xAPIC IDs. Yell, but don't kill the VM, as KVM can continue on + * without the optimized map. + */ + if (WARN_ON_ONCE(xapic_id > new->max_apic_id)) + return -EINVAL; + + /* + * Bail if a vCPU was added and/or enabled its APIC between allocating + * the map and doing the actual calculations for the map. Note, KVM + * hardcodes the x2APIC ID to vcpu_id, i.e. there's no TOCTOU bug if + * the compiler decides to reload x2apic_id after this check. + */ + if (x2apic_id > new->max_apic_id) + return -E2BIG; + + /* + * 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) + 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_apic_map *map = container_of(rcu, struct kvm_apic_map, rcu); + 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; + } - kvfree(map); + /* + * 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)) + 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; } /* @@ -181,21 +345,31 @@ enum { DIRTY }; -void kvm_recalculate_apic_map(struct kvm *kvm) +static void kvm_recalculate_apic_map(struct kvm *kvm) { struct kvm_apic_map *new, *old = NULL; struct kvm_vcpu *vcpu; - int i; + unsigned long i; u32 max_id = 255; /* enough space for any xAPIC ID */ + bool xapic_id_mismatch; + int r; /* 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); + +retry: /* - * Read kvm->arch.apic_map_dirty before kvm->arch.apic_map - * (if clean) or the APIC registers (if dirty). + * Read kvm->arch.apic_map_dirty before kvm->arch.apic_map (if clean) + * or the APIC registers (if dirty). Note, on retry the map may have + * not yet been marked dirty by whatever task changed a vCPU's x2APIC + * ID, i.e. the map may still show up as in-progress. In that case + * this task still needs to retry and complete its calculation. */ if (atomic_cmpxchg_acquire(&kvm->arch.apic_map_dirty, DIRTY, UPDATE_IN_PROGRESS) == CLEAN) { @@ -204,6 +378,15 @@ void kvm_recalculate_apic_map(struct kvm *kvm) return; } + /* + * Reset the mismatch flag between attempts so that KVM does the right + * thing if a vCPU changes its xAPIC ID, but do NOT reset max_id, i.e. + * keep max_id strictly increasing. Disallowing max_id from shrinking + * ensures KVM won't get stuck in an infinite loop, e.g. if the vCPU + * with the highest x2APIC ID is toggling its APIC on and off. + */ + xapic_id_mismatch = false; + kvm_for_each_vcpu(i, vcpu, kvm) if (kvm_apic_present(vcpu)) max_id = max(max_id, kvm_x2apic_id(vcpu->arch.apic)); @@ -216,54 +399,47 @@ 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); + r = kvm_recalculate_phys_map(new, vcpu, &xapic_id_mismatch); + if (r) { + kvfree(new); + new = NULL; + if (r == -E2BIG) { + cond_resched(); + goto retry; + } - 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; + 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); @@ -276,7 +452,7 @@ out: mutex_unlock(&kvm->arch.apic_map_lock); if (old) - call_rcu(&old->rcu, kvm_apic_map_free); + kvfree_rcu(old, rcu); kvm_make_scan_ioapic_request(kvm); } @@ -298,8 +474,10 @@ static inline void apic_set_spiv(struct kvm_lapic *apic, u32 val) } /* Check if there are APF page ready requests pending */ - if (enabled) + if (enabled) { kvm_make_request(KVM_REQ_APF_READY, apic->vcpu); + kvm_xen_sw_enable_lapic(apic->vcpu); + } } static inline void kvm_apic_set_xapic_id(struct kvm_lapic *apic, u8 id) @@ -320,11 +498,6 @@ 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); @@ -361,14 +534,26 @@ 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 = APIC_VERSION; + 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 @@ -376,35 +561,41 @@ void kvm_apic_set_version(struct kvm_vcpu *vcpu) * version first and level-triggered interrupts never get EOIed in * IOAPIC. */ - if (guest_cpuid_has(vcpu, X86_FEATURE_X2APIC) && + if (guest_cpu_cap_has(vcpu, X86_FEATURE_X2APIC) && !ioapic_in_kernel(vcpu->kvm)) v |= APIC_LVR_DIRECTED_EOI; kvm_lapic_set_reg(apic, APIC_LVR, v); } -static const unsigned int apic_lvt_mask[KVM_APIC_LVT_NUM] = { - LVT_MASK , /* part LVTT mask, timer mode mask added at runtime */ - LVT_MASK | APIC_MODE_MASK, /* LVTTHMR */ - LVT_MASK | APIC_MODE_MASK, /* LVTPC */ - LINT_MASK, LINT_MASK, /* LVT0-1 */ - LVT_MASK /* LVTERR */ -}; - -static int find_highest_vector(void *bitmap) +void kvm_apic_after_set_mcg_cap(struct kvm_vcpu *vcpu) { - int vec; - u32 *reg; + int nr_lvt_entries = kvm_apic_calc_nr_lvt_entries(vcpu); + struct kvm_lapic *apic = vcpu->arch.apic; + int i; - 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; - } + 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; - return -1; + /* 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 u8 count_vectors(void *bitmap) { int vec; @@ -412,33 +603,41 @@ static u8 count_vectors(void *bitmap) u8 count = 0; for (vec = 0; vec < MAX_APIC_VECTOR; vec += APIC_VECTORS_PER_REG) { - reg = bitmap + REG_POS(vec); + reg = bitmap + APIC_VECTOR_TO_REG_OFFSET(vec); count += hweight32(*reg); } return count; } -bool __kvm_apic_update_irr(u32 *pir, void *regs, int *max_irr) +bool __kvm_apic_update_irr(unsigned long *pir, void *regs, int *max_irr) { + unsigned long pir_vals[NR_PIR_WORDS]; + u32 *__pir = (void *)pir_vals; u32 i, vec; - u32 pir_val, irr_val, prev_irr_val; + u32 irr_val, prev_irr_val; int max_updated_irr; max_updated_irr = -1; *max_irr = -1; + if (!pi_harvest_pir(pir, pir_vals)) + return false; + 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) { + u32 *p_irr = (u32 *)(regs + APIC_IRR + i * 0x10); + + irr_val = READ_ONCE(*p_irr); + + if (__pir[i]) { 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; - } + do { + irr_val = prev_irr_val | __pir[i]; + } while (prev_irr_val != irr_val && + !try_cmpxchg(p_irr, &prev_irr_val, 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; @@ -447,19 +646,22 @@ bool __kvm_apic_update_irr(u32 *pir, void *regs, int *max_irr) return ((max_updated_irr != -1) && (max_updated_irr == *max_irr)); } -EXPORT_SYMBOL_GPL(__kvm_apic_update_irr); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(__kvm_apic_update_irr); -bool kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir, int *max_irr) +bool kvm_apic_update_irr(struct kvm_vcpu *vcpu, unsigned long *pir, int *max_irr) { struct kvm_lapic *apic = vcpu->arch.apic; + bool irr_updated = __kvm_apic_update_irr(pir, apic->regs, max_irr); - return __kvm_apic_update_irr(pir, apic->regs, max_irr); + if (unlikely(!apic->apicv_active && irr_updated)) + apic->irr_pending = true; + return irr_updated; } -EXPORT_SYMBOL_GPL(kvm_apic_update_irr); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_update_irr); static inline int apic_search_irr(struct kvm_lapic *apic) { - return find_highest_vector(apic->regs + APIC_IRR); + return apic_find_highest_vector(apic->regs + APIC_IRR); } static inline int apic_find_highest_irr(struct kvm_lapic *apic) @@ -481,18 +683,11 @@ static inline int apic_find_highest_irr(struct kvm_lapic *apic) static inline void apic_clear_irr(int vec, struct kvm_lapic *apic) { - struct kvm_vcpu *vcpu; - - vcpu = apic->vcpu; - - if (unlikely(vcpu->arch.apicv_active)) { - /* need to update RVI */ - kvm_lapic_clear_vector(vec, apic->regs + APIC_IRR); - static_call(kvm_x86_hwapic_irr_update)(vcpu, - apic_find_highest_irr(apic)); + if (unlikely(apic->apicv_active)) { + apic_clear_vector(vec, apic->regs + APIC_IRR); } else { apic->irr_pending = false; - kvm_lapic_clear_vector(vec, apic->regs + APIC_IRR); + apic_clear_vector(vec, apic->regs + APIC_IRR); if (apic_search_irr(apic) != -1) apic->irr_pending = true; } @@ -502,24 +697,26 @@ 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); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_clear_irr); -static inline void apic_set_isr(int vec, struct kvm_lapic *apic) +static void *apic_vector_to_isr(int vec, struct kvm_lapic *apic) { - struct kvm_vcpu *vcpu; + return apic->regs + APIC_ISR + APIC_VECTOR_TO_REG_OFFSET(vec); +} - if (__apic_test_and_set_vector(vec, apic->regs + APIC_ISR)) +static inline void apic_set_isr(int vec, struct kvm_lapic *apic) +{ + if (__test_and_set_bit(APIC_VECTOR_TO_BIT_NUMBER(vec), + apic_vector_to_isr(vec, apic))) return; - vcpu = apic->vcpu; - /* * With APIC virtualization enabled, all caching is disabled * because the processor can modify ISR under the hood. Instead * just set SVI. */ - if (unlikely(vcpu->arch.apicv_active)) - static_call(kvm_x86_hwapic_isr_update)(vcpu, vec); + if (unlikely(apic->apicv_active)) + kvm_x86_call(hwapic_isr_update)(apic->vcpu, vec); else { ++apic->isr_count; BUG_ON(apic->isr_count > MAX_APIC_VECTOR); @@ -545,7 +742,7 @@ static inline int apic_find_highest_isr(struct kvm_lapic *apic) if (likely(apic->highest_isr_cache != -1)) return apic->highest_isr_cache; - result = find_highest_vector(apic->regs + APIC_ISR); + result = apic_find_highest_vector(apic->regs + APIC_ISR); ASSERT(result == -1 || result >= 16); return result; @@ -553,12 +750,10 @@ static inline int apic_find_highest_isr(struct kvm_lapic *apic) static inline void apic_clear_isr(int vec, struct kvm_lapic *apic) { - struct kvm_vcpu *vcpu; - if (!__apic_test_and_clear_vector(vec, apic->regs + APIC_ISR)) + if (!__test_and_clear_bit(APIC_VECTOR_TO_BIT_NUMBER(vec), + apic_vector_to_isr(vec, apic))) return; - vcpu = apic->vcpu; - /* * We do get here for APIC virtualization enabled if the guest * uses the Hyper-V APIC enlightenment. In this case we may need @@ -566,9 +761,8 @@ static inline void apic_clear_isr(int vec, struct kvm_lapic *apic) * on the other hand isr_count and highest_isr_cache are unused * and must be left alone. */ - if (unlikely(vcpu->arch.apicv_active)) - static_call(kvm_x86_hwapic_isr_update)(vcpu, - apic_find_highest_isr(apic)); + if (unlikely(apic->apicv_active)) + kvm_x86_call(hwapic_isr_update)(apic->vcpu, apic_find_highest_isr(apic)); else { --apic->isr_count; BUG_ON(apic->isr_count < 0); @@ -576,6 +770,17 @@ static inline void apic_clear_isr(int vec, struct kvm_lapic *apic) } } +void kvm_apic_update_hwapic_isr(struct kvm_vcpu *vcpu) +{ + struct kvm_lapic *apic = vcpu->arch.apic; + + if (WARN_ON_ONCE(!lapic_in_kernel(vcpu)) || !apic->apicv_active) + return; + + kvm_x86_call(hwapic_isr_update)(vcpu, apic_find_highest_isr(apic)); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_update_hwapic_isr); + int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu) { /* This may race with setting of irr in __apic_accept_irq() and @@ -585,7 +790,7 @@ int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu) */ return apic_find_highest_irr(vcpu->arch.apic); } -EXPORT_SYMBOL_GPL(kvm_lapic_find_highest_irr); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_lapic_find_highest_irr); static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, int vector, int level, int trig_mode, @@ -609,6 +814,8 @@ static int __pv_send_ipi(unsigned long *ipi_bitmap, struct kvm_apic_map *map, if (min > map->max_apic_id) return 0; + min = array_index_nospec(min, map->max_apic_id + 1); + for_each_set_bit(i, ipi_bitmap, min((u32)BITS_PER_LONG, (map->max_apic_id - min + 1))) { if (map->phys_map[min + i]) { @@ -670,42 +877,41 @@ static inline bool pv_eoi_enabled(struct kvm_vcpu *vcpu) return vcpu->arch.pv_eoi.msr_val & KVM_MSR_ENABLED; } -static bool pv_eoi_get_pending(struct kvm_vcpu *vcpu) -{ - u8 val; - if (pv_eoi_get_user(vcpu, &val) < 0) { - printk(KERN_WARNING "Can't read EOI MSR value: 0x%llx\n", - (unsigned long long)vcpu->arch.pv_eoi.msr_val); - return false; - } - return val & KVM_PV_EOI_ENABLED; -} - static void pv_eoi_set_pending(struct kvm_vcpu *vcpu) { - if (pv_eoi_put_user(vcpu, KVM_PV_EOI_ENABLED) < 0) { - printk(KERN_WARNING "Can't set EOI MSR value: 0x%llx\n", - (unsigned long long)vcpu->arch.pv_eoi.msr_val); + if (pv_eoi_put_user(vcpu, KVM_PV_EOI_ENABLED) < 0) return; - } + __set_bit(KVM_APIC_PV_EOI_PENDING, &vcpu->arch.apic_attention); } -static void pv_eoi_clr_pending(struct kvm_vcpu *vcpu) +static bool pv_eoi_test_and_clr_pending(struct kvm_vcpu *vcpu) { - if (pv_eoi_put_user(vcpu, KVM_PV_EOI_DISABLED) < 0) { - printk(KERN_WARNING "Can't clear EOI MSR value: 0x%llx\n", - (unsigned long long)vcpu->arch.pv_eoi.msr_val); - return; - } + 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 (apic->vcpu->arch.apicv_active) - highest_irr = static_call(kvm_x86_sync_pir_to_irr)(apic->vcpu); + if (kvm_x86_ops.sync_pir_to_irr) + highest_irr = kvm_x86_call(sync_pir_to_irr)(apic->vcpu); else highest_irr = apic_find_highest_irr(apic); if (highest_irr == -1 || (highest_irr & 0xF0) <= ppr) @@ -748,7 +954,7 @@ void kvm_apic_update_ppr(struct kvm_vcpu *vcpu) { apic_update_ppr(vcpu->arch.apic); } -EXPORT_SYMBOL_GPL(kvm_apic_update_ppr); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_update_ppr); static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr) { @@ -767,17 +973,17 @@ static bool kvm_apic_match_physical_addr(struct kvm_lapic *apic, u32 mda) if (kvm_apic_broadcast(apic, mda)) return true; - if (apic_x2apic_mode(apic)) - return mda == kvm_x2apic_id(apic); - /* - * Hotplug hack: Make LAPIC in xAPIC mode also accept interrupts as if - * it were in x2APIC mode. Hotplugged VCPUs start in xAPIC mode and - * this allows unique addressing of VCPUs with APIC ID over 0xff. - * The 0xff condition is needed because writeable xAPIC ID. + * 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 (kvm_x2apic_id(apic) > 0xff && mda == kvm_x2apic_id(apic)) - return true; + if (apic_x2apic_mode(apic) || mda > 0xff) + return mda == kvm_x2apic_id(apic); return mda == kvm_xapic_id(apic); } @@ -859,21 +1065,14 @@ bool kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source, return false; } } -EXPORT_SYMBOL_GPL(kvm_apic_match_dest); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_match_dest); -int kvm_vector_to_index(u32 vector, u32 dest_vcpus, - const unsigned long *bitmap, u32 bitmap_size) +static 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); - } + int idx = find_nth_bit(bitmap, bitmap_size, vector % dest_vcpus); + BUG_ON(idx >= bitmap_size); return idx; } @@ -881,8 +1080,7 @@ 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"); + pr_info("Disabled LAPIC found during irq injection\n"); } } @@ -891,7 +1089,7 @@ 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; @@ -905,6 +1103,16 @@ static bool kvm_apic_is_broadcast_dest(struct kvm *kvm, struct kvm_lapic **src, return false; } +static bool kvm_lowest_prio_delivery(struct kvm_lapic_irq *irq) +{ + return (irq->delivery_mode == APIC_DM_LOWEST || irq->msi_redir_hint); +} + +static int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2) +{ + return vcpu1->arch.apic_arb_prio - vcpu2->arch.apic_arb_prio; +} + /* 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. @@ -948,7 +1156,7 @@ static inline bool kvm_apic_map_get_dest_lapic(struct kvm *kvm, if (!kvm_lowest_prio_delivery(irq)) return true; - if (!kvm_vector_hashing_enabled()) { + if (!vector_hashing_enabled) { lowest = -1; for_each_set_bit(i, bitmap, 16) { if (!(*dst)[i]) @@ -990,6 +1198,10 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, *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; } @@ -1025,8 +1237,9 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src, * 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) +static 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; @@ -1053,6 +1266,91 @@ bool kvm_intr_is_single_vcpu_fast(struct kvm *kvm, struct kvm_lapic_irq *irq, return ret; } +bool kvm_intr_is_single_vcpu(struct kvm *kvm, struct kvm_lapic_irq *irq, + struct kvm_vcpu **dest_vcpu) +{ + int r = 0; + unsigned long i; + struct kvm_vcpu *vcpu; + + if (kvm_intr_is_single_vcpu_fast(kvm, irq, dest_vcpu)) + return true; + + 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; + + if (++r == 2) + return false; + + *dest_vcpu = vcpu; + } + + return r == 1; +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_intr_is_single_vcpu); + +int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src, + struct kvm_lapic_irq *irq, struct dest_map *dest_map) +{ + int r = -1; + struct kvm_vcpu *vcpu, *lowest = NULL; + unsigned long i, dest_vcpu_bitmap[BITS_TO_LONGS(KVM_MAX_VCPUS)]; + unsigned int dest_vcpus = 0; + + if (kvm_irq_delivery_to_apic_fast(kvm, src, irq, &r, dest_map)) + return r; + + if (irq->dest_mode == APIC_DEST_PHYSICAL && + irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) { + pr_info("apic: phys broadcast and lowest prio\n"); + irq->delivery_mode = APIC_DM_FIXED; + } + + memset(dest_vcpu_bitmap, 0, sizeof(dest_vcpu_bitmap)); + + kvm_for_each_vcpu(i, vcpu, kvm) { + if (!kvm_apic_present(vcpu)) + continue; + + if (!kvm_apic_match_dest(vcpu, src, irq->shorthand, + irq->dest_id, irq->dest_mode)) + continue; + + if (!kvm_lowest_prio_delivery(irq)) { + if (r < 0) + r = 0; + r += kvm_apic_set_irq(vcpu, irq, dest_map); + } else if (kvm_apic_sw_enabled(vcpu->arch.apic)) { + if (!vector_hashing_enabled) { + if (!lowest) + lowest = vcpu; + else if (kvm_apic_compare_prio(vcpu, lowest) < 0) + lowest = vcpu; + } else { + __set_bit(i, dest_vcpu_bitmap); + dest_vcpus++; + } + } + } + + if (dest_vcpus != 0) { + int idx = kvm_vector_to_index(irq->vector, dest_vcpus, + dest_vcpu_bitmap, KVM_MAX_VCPUS); + + lowest = kvm_get_vcpu(kvm, idx); + } + + if (lowest) + r = kvm_apic_set_irq(lowest, irq, dest_map); + + return r; +} + /* * Add a pending IRQ into lapic. * Return 1 if successfully added and 0 if discarded. @@ -1087,18 +1385,13 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, if (apic_test_vector(vector, apic->regs + APIC_TMR) != !!trig_mode) { if (trig_mode) - kvm_lapic_set_vector(vector, - apic->regs + APIC_TMR); + apic_set_vector(vector, apic->regs + APIC_TMR); else - kvm_lapic_clear_vector(vector, - apic->regs + APIC_TMR); + apic_clear_vector(vector, apic->regs + APIC_TMR); } - if (static_call(kvm_x86_deliver_posted_interrupt)(vcpu, vector)) { - kvm_lapic_set_irr(vector, apic); - kvm_make_request(KVM_REQ_EVENT, vcpu); - kvm_vcpu_kick(vcpu); - } + kvm_x86_call(deliver_interrupt)(apic, delivery_mode, + trig_mode, vector); break; case APIC_DM_REMRD: @@ -1109,9 +1402,10 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode, break; case APIC_DM_SMI: - result = 1; - kvm_make_request(KVM_REQ_SMI, vcpu); - kvm_vcpu_kick(vcpu); + if (!kvm_inject_smi(vcpu)) { + kvm_vcpu_kick(vcpu); + result = 1; + } break; case APIC_DM_NMI: @@ -1169,8 +1463,8 @@ void kvm_bitmap_or_dest_vcpus(struct kvm *kvm, struct kvm_lapic_irq *irq, struct kvm_lapic *src = NULL; struct kvm_apic_map *map; struct kvm_vcpu *vcpu; - unsigned long bitmap; - int i, vcpu_idx; + unsigned long bitmap, i; + int vcpu_idx; bool ret; rcu_read_lock(); @@ -1200,11 +1494,6 @@ void kvm_bitmap_or_dest_vcpus(struct kvm *kvm, struct kvm_lapic_irq *irq, 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); @@ -1212,12 +1501,20 @@ static bool kvm_ioapic_handles_vector(struct kvm_lapic *apic, int vector) static void kvm_ioapic_send_eoi(struct kvm_lapic *apic, int vector) { - int trigger_mode; + int __maybe_unused trigger_mode; /* Eoi the ioapic only if the ioapic doesn't own the vector. */ if (!kvm_ioapic_handles_vector(apic, vector)) return; + /* + * If the intercepted EOI is for an IRQ that was pending from previous + * routing, then re-scan the I/O APIC routes as EOIs for the IRQ likely + * no longer need to be intercepted. + */ + if (apic->vcpu->arch.highest_stale_pending_ioapic_eoi == vector) + kvm_make_request(KVM_REQ_SCAN_IOAPIC, apic->vcpu); + /* Request a KVM exit to inform the userspace IOAPIC. */ if (irqchip_split(apic->vcpu->kvm)) { apic->vcpu->arch.pending_ioapic_eoi = vector; @@ -1225,12 +1522,14 @@ static void kvm_ioapic_send_eoi(struct kvm_lapic *apic, int vector) return; } +#ifdef CONFIG_KVM_IOAPIC 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); +#endif } static int apic_set_eoi(struct kvm_lapic *apic) @@ -1249,8 +1548,7 @@ static int apic_set_eoi(struct kvm_lapic *apic) 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)) + if (kvm_hv_synic_has_vector(apic->vcpu, vector)) kvm_hv_synic_send_eoi(apic->vcpu, vector); kvm_ioapic_send_eoi(apic, vector); @@ -1271,34 +1569,43 @@ void kvm_apic_set_eoi_accelerated(struct kvm_vcpu *vcpu, int vector) kvm_ioapic_send_eoi(apic, vector); kvm_make_request(KVM_REQ_EVENT, apic->vcpu); } -EXPORT_SYMBOL_GPL(kvm_apic_set_eoi_accelerated); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_set_eoi_accelerated); -void kvm_apic_send_ipi(struct kvm_lapic *apic, u32 icr_low, u32 icr_high) +static void kvm_icr_to_lapic_irq(struct kvm_lapic *apic, u32 icr_low, + u32 icr_high, struct kvm_lapic_irq *irq) { - 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; + 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; + irq->dest_id = icr_high; else - irq.dest_id = GET_APIC_DEST_FIELD(icr_high); + irq->dest_id = GET_XAPIC_DEST_FIELD(icr_high); +} + +void kvm_apic_send_ipi(struct kvm_lapic *apic, u32 icr_low, u32 icr_high) +{ + struct kvm_lapic_irq irq; + + kvm_icr_to_lapic_irq(apic, icr_low, icr_high, &irq); trace_kvm_apic_ipi(icr_low, irq.dest_id); kvm_irq_delivery_to_apic(apic->vcpu->kvm, apic, &irq, NULL); } +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_send_ipi); static u32 apic_get_tmcct(struct kvm_lapic *apic) { ktime_t remaining, now; s64 ns; - u32 tmcct; ASSERT(apic != NULL); @@ -1313,10 +1620,8 @@ static u32 apic_get_tmcct(struct kvm_lapic *apic) 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; + return div64_u64(ns, (apic->vcpu->kvm->arch.apic_bus_cycle_ns * + apic->divide_count)); } static void __report_tpr_access(struct kvm_lapic *apic, bool write) @@ -1376,26 +1681,21 @@ static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev) #define APIC_REGS_MASK(first, count) \ (APIC_REG_MASK(first) * ((1ull << (count)) - 1)) -int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, - void *data) +u64 kvm_lapic_readable_reg_mask(struct kvm_lapic *apic) { - unsigned char alignment = offset & 0xf; - u32 result; - /* this bitmask has a bit cleared for each reserved register */ + /* Leave bits '0' for reserved and write-only registers. */ 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_ICR2) | APIC_REG_MASK(APIC_LVTT) | APIC_REG_MASK(APIC_LVTTHMR) | APIC_REG_MASK(APIC_LVTPC) | @@ -1406,14 +1706,36 @@ int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, APIC_REG_MASK(APIC_TMCCT) | APIC_REG_MASK(APIC_TDCR); - /* ARBPRI is not valid on x2APIC */ + if (kvm_lapic_lvt_supported(apic, LVT_CMCI)) + valid_reg_mask |= APIC_REG_MASK(APIC_LVTCMCI); + + /* ARBPRI, DFR, and ICR2 are not valid in x2APIC mode. */ if (!apic_x2apic_mode(apic)) - valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI); + valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI) | + APIC_REG_MASK(APIC_DFR) | + APIC_REG_MASK(APIC_ICR2); + + return valid_reg_mask; +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_lapic_readable_reg_mask); + +static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, + void *data) +{ + unsigned char alignment = offset & 0xf; + u32 result; + + /* + * 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. + */ + WARN_ON_ONCE(apic_x2apic_mode(apic) && offset == APIC_ICR); if (alignment + len > 4) return 1; - if (offset > 0x3f0 || !(valid_reg_mask & APIC_REG_MASK(offset))) + if (offset > 0x3f0 || + !(kvm_lapic_readable_reg_mask(apic) & APIC_REG_MASK(offset))) return 1; result = __apic_read(apic, offset & ~0xf); @@ -1433,7 +1755,6 @@ int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, } return 0; } -EXPORT_SYMBOL_GPL(kvm_lapic_reg_read); static int apic_mmio_in_range(struct kvm_lapic *apic, gpa_t addr) { @@ -1485,8 +1806,8 @@ static void limit_periodic_timer_frequency(struct kvm_lapic *apic) s64 min_period = min_timer_period_us * 1000LL; if (apic->lapic_timer.period < min_period) { - pr_info_ratelimited( - "kvm: vcpu %i: requested %lld ns " + pr_info_once( + "vcpu %i: requested %lld ns " "lapic timer period limited to %lld ns\n", apic->vcpu->vcpu_id, apic->lapic_timer.period, min_period); @@ -1504,6 +1825,7 @@ static void cancel_apic_timer(struct kvm_lapic *apic) 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) @@ -1532,13 +1854,22 @@ static void apic_update_lvtt(struct kvm_lapic *apic) 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); + u32 reg; + + /* + * Assume a timer IRQ was "injected" if the APIC is protected. KVM's + * copy of the vIRR is bogus, it's the responsibility of the caller to + * precisely check whether or not a timer IRQ is pending. + */ + if (apic->guest_apic_protected) + return true; + 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 (vcpu->arch.apicv_active) + if (apic->apicv_active) bitmap = apic->regs + APIC_IRR; if (apic_test_vector(vec, bitmap)) @@ -1557,7 +1888,7 @@ static inline void __wait_lapic_expire(struct kvm_vcpu *vcpu, u64 guest_cycles) * that __delay() uses delay_tsc whenever the hardware has TSC, thus * always for VMX enabled hardware. */ - if (vcpu->arch.tsc_scaling_ratio == kvm_default_tsc_scaling_ratio) { + if (vcpu->arch.tsc_scaling_ratio == kvm_caps.default_tsc_scaling_ratio) { __delay(min(guest_cycles, nsec_to_cycles(vcpu, timer_advance_ns))); } else { @@ -1604,18 +1935,16 @@ static void __kvm_wait_lapic_expire(struct kvm_vcpu *vcpu) tsc_deadline = apic->lapic_timer.expired_tscdeadline; apic->lapic_timer.expired_tscdeadline = 0; guest_tsc = kvm_read_l1_tsc(vcpu, rdtsc()); - apic->lapic_timer.advance_expire_delta = guest_tsc - tsc_deadline; + trace_kvm_wait_lapic_expire(vcpu->vcpu_id, guest_tsc - tsc_deadline); - if (lapic_timer_advance_dynamic) { - adjust_lapic_timer_advance(vcpu, apic->lapic_timer.advance_expire_delta); - /* - * 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()); - } + 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); @@ -1629,7 +1958,7 @@ void kvm_wait_lapic_expire(struct kvm_vcpu *vcpu) lapic_timer_int_injected(vcpu)) __kvm_wait_lapic_expire(vcpu); } -EXPORT_SYMBOL_GPL(kvm_wait_lapic_expire); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_wait_lapic_expire); static void kvm_apic_inject_pending_timer_irqs(struct kvm_lapic *apic) { @@ -1655,7 +1984,7 @@ static void apic_timer_expired(struct kvm_lapic *apic, bool from_timer_fn) if (apic_lvtt_tscdeadline(apic) || ktimer->hv_timer_in_use) ktimer->expired_tscdeadline = ktimer->tscdeadline; - if (!from_timer_fn && vcpu->arch.apicv_active) { + if (!from_timer_fn && apic->apicv_active) { WARN_ON(kvm_get_running_vcpu() != vcpu); kvm_apic_inject_pending_timer_irqs(apic); return; @@ -1689,7 +2018,7 @@ static void start_sw_tscdeadline(struct kvm_lapic *apic) u64 ns = 0; ktime_t expire; struct kvm_vcpu *vcpu = apic->vcpu; - unsigned long this_tsc_khz = vcpu->arch.virtual_tsc_khz; + u32 this_tsc_khz = vcpu->arch.virtual_tsc_khz; unsigned long flags; ktime_t now; @@ -1717,7 +2046,8 @@ static void start_sw_tscdeadline(struct kvm_lapic *apic) static inline u64 tmict_to_ns(struct kvm_lapic *apic, u32 tmict) { - return (u64)tmict * APIC_BUS_CYCLE_NS * (u64)apic->divide_count; + return (u64)tmict * apic->vcpu->kvm->arch.apic_bus_cycle_ns * + (u64)apic->divide_count; } static void update_target_expiration(struct kvm_lapic *apic, uint32_t old_divisor) @@ -1766,11 +2096,15 @@ static bool set_target_expiration(struct kvm_lapic *apic, u32 count_reg) 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; + if (unlikely(deadline <= 0)) { + if (apic_lvtt_period(apic)) + deadline = apic->lapic_timer.period; + else + deadline = 0; + } else if (unlikely(deadline > apic->lapic_timer.period)) { pr_info_ratelimited( - "kvm: vcpu %i: requested lapic timer restore with " + "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, @@ -1792,23 +2126,41 @@ static bool set_target_expiration(struct kvm_lapic *apic, u32 count_reg) static void advance_periodic_target_expiration(struct kvm_lapic *apic) { + struct kvm_timer *ktimer = &apic->lapic_timer; 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. + * Use kernel time as the time source for both the hrtimer deadline and + * TSC-based deadline so that they stay synchronized. Computing each + * deadline independently will cause the two deadlines to drift apart + * over time as differences in the periods accumulate, e.g. due to + * differences in the underlying clocks or numerical approximation errors. */ - 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); + ktimer->target_expiration = ktime_add_ns(ktimer->target_expiration, + ktimer->period); + + /* + * If the new expiration is in the past, e.g. because userspace stopped + * running the VM for an extended duration, then force the expiration + * to "now" and don't try to play catch-up with the missed events. KVM + * will only deliver a single interrupt regardless of how many events + * are pending, i.e. restarting the timer with an expiration in the + * past will do nothing more than waste host cycles, and can even lead + * to a hard lockup in extreme cases. + */ + if (ktime_before(ktimer->target_expiration, now)) + ktimer->target_expiration = now; + + /* + * Note, ensuring the expiration isn't in the past also prevents delta + * from going negative, which could cause the TSC deadline to become + * excessively large due to it an unsigned value. + */ + delta = ktime_sub(ktimer->target_expiration, now); + ktimer->tscdeadline = kvm_read_l1_tsc(apic->vcpu, tscl) + + nsec_to_cycles(apic->vcpu, delta); } static void start_sw_period(struct kvm_lapic *apic) @@ -1838,13 +2190,12 @@ bool kvm_lapic_hv_timer_in_use(struct kvm_vcpu *vcpu) 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); + kvm_x86_call(cancel_hv_timer)(apic->vcpu); apic->lapic_timer.hv_timer_in_use = false; } @@ -1861,7 +2212,7 @@ static bool start_hv_timer(struct kvm_lapic *apic) if (!ktimer->tscdeadline) return false; - if (static_call(kvm_x86_set_hv_timer)(vcpu, ktimer->tscdeadline, &expired)) + if (kvm_x86_call(set_hv_timer)(vcpu, ktimer->tscdeadline, &expired)) return false; ktimer->hv_timer_in_use = true; @@ -1928,7 +2279,7 @@ void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu) /* 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(rcuwait_active(&vcpu->wait)); + WARN_ON(kvm_vcpu_is_blocking(vcpu)); apic_timer_expired(apic, false); cancel_hv_timer(apic); @@ -1939,13 +2290,12 @@ void kvm_lapic_expired_hv_timer(struct kvm_vcpu *vcpu) out: preempt_enable(); } -EXPORT_SYMBOL_GPL(kvm_lapic_expired_hv_timer); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_lapic_expired_hv_timer); void kvm_lapic_switch_to_hv_timer(struct kvm_vcpu *vcpu) { restart_apic_timer(vcpu->arch.apic); } -EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_hv_timer); void kvm_lapic_switch_to_sw_timer(struct kvm_vcpu *vcpu) { @@ -1957,7 +2307,6 @@ void kvm_lapic_switch_to_sw_timer(struct kvm_vcpu *vcpu) start_sw_timer(apic); preempt_enable(); } -EXPORT_SYMBOL_GPL(kvm_lapic_switch_to_sw_timer); void kvm_lapic_restart_hv_timer(struct kvm_vcpu *vcpu) { @@ -1996,7 +2345,17 @@ static void apic_manage_nmi_watchdog(struct kvm_lapic *apic, u32 lvt0_val) } } -int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) +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; @@ -2004,10 +2363,11 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) switch (reg) { case APIC_ID: /* Local APIC ID */ - if (!apic_x2apic_mode(apic)) + if (!apic_x2apic_mode(apic)) { kvm_apic_set_xapic_id(apic, val >> 24); - else + } else { ret = 1; + } break; case APIC_TASKPRI: @@ -2040,13 +2400,10 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) apic_set_spiv(apic, val & mask); if (!(val & APIC_SPIV_APIC_ENABLED)) { int i; - u32 lvt_val; - for (i = 0; i < KVM_APIC_LVT_NUM; i++) { - lvt_val = kvm_lapic_get_reg(apic, - APIC_LVTT + 0x10 * i); - kvm_lapic_set_reg(apic, APIC_LVTT + 0x10 * i, - lvt_val | APIC_LVT_MASKED); + 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); @@ -2055,16 +2412,18 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) break; } case APIC_ICR: + WARN_ON_ONCE(apic_x2apic_mode(apic)); + /* No delay here, so we always clear the pending bit */ - val &= ~(1 << 12); + 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)) - val &= 0xff000000; - kvm_lapic_set_reg(apic, APIC_ICR2, val); + if (apic_x2apic_mode(apic)) + ret = 1; + else + kvm_lapic_set_reg(apic, APIC_ICR2, val & 0xff000000); break; case APIC_LVT0: @@ -2073,16 +2432,15 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) case APIC_LVTTHMR: case APIC_LVTPC: case APIC_LVT1: - case APIC_LVTERR: { - /* TODO: Check vector */ - size_t size; - u32 index; - + 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; - size = ARRAY_SIZE(apic_lvt_mask); - index = array_index_nospec( - (reg - APIC_LVTT) >> 4, size); val &= apic_lvt_mask[index]; kvm_lapic_set_reg(apic, reg, val); break; @@ -2091,7 +2449,7 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) case APIC_LVTT: if (!kvm_apic_sw_enabled(apic)) val |= APIC_LVT_MASKED; - val &= (apic_lvt_mask[0] | apic->lapic_timer.timer_mode_mask); + val &= (apic_lvt_mask[LVT_TIMER] | apic->lapic_timer.timer_mode_mask); kvm_lapic_set_reg(apic, APIC_LVTT, val); apic_update_lvtt(apic); break; @@ -2124,22 +2482,29 @@ int kvm_lapic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val) break; case APIC_SELF_IPI: - if (apic_x2apic_mode(apic)) { - kvm_lapic_reg_write(apic, APIC_ICR, - APIC_DEST_SELF | (val & APIC_VECTOR_MASK)); - } else + /* + * 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; } -EXPORT_SYMBOL_GPL(kvm_lapic_reg_write); static int apic_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *this, gpa_t address, int len, const void *data) @@ -2178,29 +2543,99 @@ 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); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_lapic_set_eoi); -/* emulate APIC access in a trap manner */ -void kvm_apic_write_nodecode(struct kvm_vcpu *vcpu, u32 offset) +#define X2APIC_ICR_RESERVED_BITS (GENMASK_ULL(31, 20) | GENMASK_ULL(17, 16) | BIT(13)) + +static int __kvm_x2apic_icr_write(struct kvm_lapic *apic, u64 data, bool fast) { - u32 val = 0; + if (data & X2APIC_ICR_RESERVED_BITS) + return 1; - /* hw has done the conditional check and inst decode */ - offset &= 0xff0; + /* + * The BUSY bit is reserved on both Intel and AMD in x2APIC mode, but + * only AMD requires it to be zero, Intel essentially just ignores the + * bit. And if IPI virtualization (Intel) or x2AVIC (AMD) is enabled, + * the CPU performs the reserved bits checks, i.e. the underlying CPU + * behavior will "win". Arbitrarily clear the BUSY bit, as there is no + * sane way to provide consistent behavior with respect to hardware. + */ + data &= ~APIC_ICR_BUSY; + + if (fast) { + struct kvm_lapic_irq irq; + int ignored; - kvm_lapic_reg_read(vcpu->arch.apic, offset, 4, &val); + kvm_icr_to_lapic_irq(apic, (u32)data, (u32)(data >> 32), &irq); - /* TODO: optimize to just emulate side effect w/o one more write */ - kvm_lapic_reg_write(vcpu->arch.apic, offset, val); + if (!kvm_irq_delivery_to_apic_fast(apic->vcpu->kvm, apic, &irq, + &ignored, NULL)) + return -EWOULDBLOCK; + + trace_kvm_apic_ipi((u32)data, irq.dest_id); + } else { + kvm_apic_send_ipi(apic, (u32)data, (u32)(data >> 32)); + } + if (kvm_x86_ops.x2apic_icr_is_split) { + kvm_lapic_set_reg(apic, APIC_ICR, data); + kvm_lapic_set_reg(apic, APIC_ICR2, data >> 32); + } else { + kvm_lapic_set_reg64(apic, APIC_ICR, data); + } + trace_kvm_apic_write(APIC_ICR, data); + return 0; +} + +static int kvm_x2apic_icr_write(struct kvm_lapic *apic, u64 data) +{ + return __kvm_x2apic_icr_write(apic, data, false); +} + +int kvm_x2apic_icr_write_fast(struct kvm_lapic *apic, u64 data) +{ + return __kvm_x2apic_icr_write(apic, data, true); +} + +static u64 kvm_x2apic_icr_read(struct kvm_lapic *apic) +{ + if (kvm_x86_ops.x2apic_icr_is_split) + return (u64)kvm_lapic_get_reg(apic, APIC_ICR) | + (u64)kvm_lapic_get_reg(apic, APIC_ICR2) << 32; + + return kvm_lapic_get_reg64(apic, APIC_ICR); +} + +/* 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; + + /* + * ICR is a single 64-bit register when x2APIC is enabled, all others + * registers hold 32-bit values. For legacy xAPIC, ICR writes need to + * go down the common path to get the upper half from ICR2. + * + * Note, using the write helpers may incur an unnecessary write to the + * virtual APIC state, but KVM needs to conditionally modify the value + * in certain cases, e.g. to clear the ICR busy bit. The cost of extra + * conditional branches is likely a wash relative to the cost of the + * maybe-unecessary write, and both are in the noise anyways. + */ + if (apic_x2apic_mode(apic) && offset == APIC_ICR) + WARN_ON_ONCE(kvm_x2apic_icr_write(apic, kvm_x2apic_icr_read(apic))); + else + kvm_lapic_reg_write(apic, offset, kvm_lapic_get_reg(apic, offset)); } -EXPORT_SYMBOL_GPL(kvm_apic_write_nodecode); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_write_nodecode); void kvm_free_lapic(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; - if (!vcpu->arch.apic) + if (!vcpu->arch.apic) { + static_branch_dec(&kvm_has_noapic_vcpu); return; + } hrtimer_cancel(&apic->lapic_timer.timer); @@ -2245,10 +2680,7 @@ void kvm_set_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu, u64 data) void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8) { - struct kvm_lapic *apic = vcpu->arch.apic; - - apic_set_tpr(apic, ((cr8 & 0x0f) << 4) - | (kvm_lapic_get_reg(apic, APIC_TASKPRI) & 4)); + apic_set_tpr(vcpu->arch.apic, (cr8 & 0x0f) << 4); } u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu) @@ -2260,18 +2692,15 @@ u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu) return (tpr & 0xf0) >> 4; } -void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) +static void __kvm_apic_set_base(struct kvm_vcpu *vcpu, u64 value) { u64 old_value = vcpu->arch.apic_base; struct kvm_lapic *apic = vcpu->arch.apic; - if (!apic) - value |= MSR_IA32_APICBASE_BSP; - vcpu->arch.apic_base = value; if ((old_value ^ value) & MSR_IA32_APICBASE_ENABLE) - kvm_update_cpuid_runtime(vcpu); + vcpu->arch.cpuid_dynamic_bits_dirty = true; if (!apic) return; @@ -2289,55 +2718,172 @@ void kvm_lapic_set_base(struct kvm_vcpu *vcpu, u64 value) } } - if (((old_value ^ value) & X2APIC_ENABLE) && (value & X2APIC_ENABLE)) - kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id); + if ((old_value ^ value) & X2APIC_ENABLE) { + if (value & X2APIC_ENABLE) + kvm_apic_set_x2apic_id(apic, vcpu->vcpu_id); + else if (value & MSR_IA32_APICBASE_ENABLE) + kvm_apic_set_xapic_id(apic, vcpu->vcpu_id); + } - if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) - static_call(kvm_x86_set_virtual_apic_mode)(vcpu); + if ((old_value ^ value) & (MSR_IA32_APICBASE_ENABLE | X2APIC_ENABLE)) { + kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu); + kvm_x86_call(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) - pr_warn_once("APIC base relocation is unsupported by KVM"); + apic->base_address != APIC_DEFAULT_PHYS_BASE) { + kvm_set_apicv_inhibit(apic->vcpu->kvm, + APICV_INHIBIT_REASON_APIC_BASE_MODIFIED); + } } +int kvm_apic_set_base(struct kvm_vcpu *vcpu, u64 value, bool host_initiated) +{ + enum lapic_mode old_mode = kvm_get_apic_mode(vcpu); + enum lapic_mode new_mode = kvm_apic_mode(value); + + if (vcpu->arch.apic_base == value) + return 0; + + u64 reserved_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu) | 0x2ff | + (guest_cpu_cap_has(vcpu, X86_FEATURE_X2APIC) ? 0 : X2APIC_ENABLE); + + if ((value & reserved_bits) != 0 || new_mode == LAPIC_MODE_INVALID) + return 1; + if (!host_initiated) { + if (old_mode == LAPIC_MODE_X2APIC && new_mode == LAPIC_MODE_XAPIC) + return 1; + if (old_mode == LAPIC_MODE_DISABLED && new_mode == LAPIC_MODE_X2APIC) + return 1; + } + + __kvm_apic_set_base(vcpu, value); + kvm_recalculate_apic_map(vcpu->kvm); + return 0; +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_set_base); + void kvm_apic_update_apicv(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic = vcpu->arch.apic; - if (vcpu->arch.apicv_active) { - /* irr_pending is always true when apicv is activated. */ - apic->irr_pending = true; + /* + * When APICv is enabled, KVM must always search the IRR for a pending + * IRQ, as other vCPUs and devices can set IRR bits even if the vCPU + * isn't running. If APICv is disabled, KVM _should_ search the IRR + * for a pending IRQ. But KVM currently doesn't ensure *all* hardware, + * e.g. CPUs and IOMMUs, has seen the change in state, i.e. searching + * the IRR at this time could race with IRQ delivery from hardware that + * still sees APICv as being enabled. + * + * FIXME: Ensure other vCPUs and devices observe the change in APICv + * state prior to updating KVM's metadata caches, so that KVM + * can safely search the IRR and set irr_pending accordingly. + */ + apic->irr_pending = true; + + if (apic->apicv_active) apic->isr_count = 1; - } else { - apic->irr_pending = (apic_search_irr(apic) != -1); + else apic->isr_count = count_vectors(apic->regs + APIC_ISR); + + apic->highest_isr_cache = -1; +} + +int kvm_alloc_apic_access_page(struct kvm *kvm) +{ + void __user *hva; + + guard(mutex)(&kvm->slots_lock); + + if (kvm->arch.apic_access_memslot_enabled || + kvm->arch.apic_access_memslot_inhibited) + return 0; + + hva = __x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, + APIC_DEFAULT_PHYS_BASE, PAGE_SIZE); + if (IS_ERR(hva)) + return PTR_ERR(hva); + + kvm->arch.apic_access_memslot_enabled = true; + + return 0; +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(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); } -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; + kvm_x86_call(apicv_pre_state_restore)(vcpu); + + 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; + + /* + * Use the inner helper to avoid an extra recalcuation of the + * optimized APIC map if some other task has dirtied the map. + * The recalculation needed for this vCPU will be done after + * all APIC state has been initialized (see below). + */ + __kvm_apic_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); - if (!init_event) { - kvm_lapic_set_base(vcpu, APIC_DEFAULT_PHYS_BASE | - MSR_IA32_APICBASE_ENABLE); + /* 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 < KVM_APIC_LVT_NUM; i++) - kvm_lapic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED); + 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)) @@ -2351,8 +2897,12 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu, bool init_event) if (!apic_x2apic_mode(apic)) kvm_apic_set_ldr(apic, 0); kvm_lapic_set_reg(apic, APIC_ESR, 0); - kvm_lapic_set_reg(apic, APIC_ICR, 0); - kvm_lapic_set_reg(apic, APIC_ICR2, 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++) { @@ -2361,18 +2911,14 @@ 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); - if (kvm_vcpu_is_bsp(vcpu)) - kvm_lapic_set_base(vcpu, - vcpu->arch.apic_base | MSR_IA32_APICBASE_BSP); + vcpu->arch.pv_eoi.msr_val = 0; apic_update_ppr(apic); - if (vcpu->arch.apicv_active) { - static_call(kvm_x86_apicv_post_state_restore)(vcpu); - static_call(kvm_x86_hwapic_irr_update)(vcpu, -1); - static_call(kvm_x86_hwapic_isr_update)(vcpu, -1); + if (apic->apicv_active) { + kvm_x86_call(apicv_post_state_restore)(vcpu); + kvm_x86_call(hwapic_isr_update)(vcpu, -1); } vcpu->arch.apic_arb_prio = 0; @@ -2406,13 +2952,18 @@ 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; + int r; 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); + + r = __apic_accept_irq(apic, mode, vector, 1, trig_mode, NULL); + if (r && lvt_type == APIC_LVTPC && + guest_cpuid_is_intel_compatible(apic->vcpu)) + kvm_lapic_set_reg(apic, APIC_LVTPC, reg | APIC_LVT_MASKED); + return r; } return 0; } @@ -2437,27 +2988,35 @@ static enum hrtimer_restart apic_timer_fn(struct hrtimer *data) apic_timer_expired(apic, true); - if (lapic_is_periodic(apic)) { + if (lapic_is_periodic(apic) && !WARN_ON_ONCE(!apic->lapic_timer.period)) { advance_periodic_target_expiration(apic); - hrtimer_add_expires_ns(&ktimer->timer, ktimer->period); + hrtimer_set_expires(&ktimer->timer, ktimer->target_expiration); return HRTIMER_RESTART; } else return HRTIMER_NORESTART; } -int kvm_create_lapic(struct kvm_vcpu *vcpu, int timer_advance_ns) +int kvm_create_lapic(struct kvm_vcpu *vcpu) { struct kvm_lapic *apic; ASSERT(vcpu != NULL); + if (!irqchip_in_kernel(vcpu->kvm)) { + static_branch_inc(&kvm_has_noapic_vcpu); + return 0; + } + 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 (kvm_x86_ops.alloc_apic_backing_page) + apic->regs = kvm_x86_call(alloc_apic_backing_page)(vcpu); + else + 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); @@ -2465,25 +3024,36 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu, int timer_advance_ns) } apic->vcpu = 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->nr_lvt_entries = kvm_apic_calc_nr_lvt_entries(vcpu); + + hrtimer_setup(&apic->lapic_timer.timer, apic_timer_fn, CLOCK_MONOTONIC, + HRTIMER_MODE_ABS_HARD); + if (lapic_timer_advance) 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; - } /* - * APIC is created enabled. This will prevent kvm_lapic_set_base from - * thinking that APIC state has changed. + * 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); + /* + * Defer evaluating inhibits until the vCPU is first run, as this vCPU + * will not get notified of any changes until this vCPU is visible to + * other vCPUs (marked online and added to the set of vCPUs). + * + * Opportunistically mark APICv active as VMX in particularly is highly + * unlikely to have inhibits. Ignore the current per-VM APICv state so + * that vCPU creation is guaranteed to run with a deterministic value, + * the request will ensure the vCPU gets the correct state before VM-Entry. + */ + if (enable_apicv) { + apic->apicv_active = true; + kvm_make_request(KVM_REQ_APICV_UPDATE, vcpu); + } + return 0; nomem_free_apic: kfree(apic); @@ -2500,10 +3070,13 @@ int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu) if (!kvm_apic_present(vcpu)) return -1; + if (apic->guest_apic_protected) + return -1; + __apic_update_ppr(apic, &ppr); return apic_has_interrupt_for_ppr(apic, ppr); } -EXPORT_SYMBOL_GPL(kvm_apic_has_interrupt); +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_has_interrupt); int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu) { @@ -2527,14 +3100,13 @@ void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu) } } -int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu) +void kvm_apic_ack_interrupt(struct kvm_vcpu *vcpu, int vector) { - int vector = kvm_apic_has_interrupt(vcpu); struct kvm_lapic *apic = vcpu->arch.apic; u32 ppr; - if (vector == -1) - return -1; + if (WARN_ON_ONCE(vector < 0 || !apic)) + return; /* * We get here even with APIC virtualization enabled, if doing @@ -2544,7 +3116,7 @@ int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu) */ apic_clear_irr(vector, apic); - if (to_hv_vcpu(vcpu) && test_bit(vector, to_hv_synic(vcpu)->auto_eoi_bitmap)) { + if (kvm_hv_synic_auto_eoi_set(vcpu, vector)) { /* * For auto-EOI interrupts, there might be another pending * interrupt above PPR, so check whether to raise another @@ -2562,29 +3134,56 @@ int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu) __apic_update_ppr(apic, &ppr); } - return vector; } +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_apic_ack_interrupt); 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 x2apic_id = kvm_x2apic_id(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) + if (*id != x2apic_id) return -EINVAL; } else { + /* + * Ignore the userspace value when setting APIC state. + * KVM's model is that the x2APIC ID is readonly, e.g. + * KVM only supports delivering interrupts to KVM's + * version of the x2APIC ID. However, for backwards + * compatibility, don't reject attempts to set a + * mismatched ID for userspace that hasn't opted into + * x2apic_format. + */ if (set) - *id >>= 24; + *id = x2apic_id; else - *id <<= 24; + *id = x2apic_id << 24; } - /* In x2APIC mode, the LDR is fixed and based on the id */ + /* + * In x2APIC mode, the LDR is fixed and based on the id. And + * if the ICR is _not_ split, 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); + *ldr = kvm_apic_calc_x2apic_ldr(x2apic_id); + + if (!kvm_x86_ops.x2apic_icr_is_split) { + if (set) { + icr = apic_get_reg(s->regs, APIC_ICR) | + (u64)apic_get_reg(s->regs, APIC_ICR2) << 32; + apic_set_reg64(s->regs, APIC_ICR, icr); + } else { + icr = apic_get_reg64(s->regs, APIC_ICR); + apic_set_reg(s->regs, APIC_ICR2, icr >> 32); + } + } } return 0; @@ -2598,8 +3197,7 @@ int kvm_apic_get_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *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)); + apic_set_reg(s->regs, APIC_TMCCT, __apic_read(vcpu->arch.apic, APIC_TMCCT)); return kvm_apic_state_fixup(vcpu, s, false); } @@ -2609,7 +3207,8 @@ 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); + kvm_x86_call(apicv_pre_state_restore)(vcpu); + /* set SPIV separately to get count of SW disabled APICs right */ apic_set_spiv(apic, *((u32 *)(s->regs + APIC_SPIV))); @@ -2625,7 +3224,7 @@ int kvm_apic_set_state(struct kvm_vcpu *vcpu, struct kvm_lapic_state *s) kvm_apic_set_version(vcpu); apic_update_ppr(apic); - hrtimer_cancel(&apic->lapic_timer.timer); + 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)); @@ -2633,17 +3232,16 @@ 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 (vcpu->arch.apicv_active) { - static_call(kvm_x86_apicv_post_state_restore)(vcpu); - static_call(kvm_x86_hwapic_irr_update)(vcpu, - apic_find_highest_irr(apic)); - static_call(kvm_x86_hwapic_isr_update)(vcpu, - apic_find_highest_isr(apic)); + if (apic->apicv_active) { + kvm_x86_call(apicv_post_state_restore)(vcpu); + kvm_x86_call(hwapic_isr_update)(vcpu, apic_find_highest_isr(apic)); } kvm_make_request(KVM_REQ_EVENT, vcpu); + +#ifdef CONFIG_KVM_IOAPIC if (ioapic_in_kernel(vcpu->kvm)) kvm_rtc_eoi_tracking_restore_one(vcpu); +#endif vcpu->arch.apic_arb_prio = 0; @@ -2673,7 +3271,6 @@ void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu) static void apic_sync_pv_eoi_from_guest(struct kvm_vcpu *vcpu, struct kvm_lapic *apic) { - bool pending; int vector; /* * PV EOI state is derived from KVM_APIC_PV_EOI_PENDING in host @@ -2687,14 +3284,8 @@ static void apic_sync_pv_eoi_from_guest(struct kvm_vcpu *vcpu, * -> host enabled PV EOI, guest executed EOI. */ BUG_ON(!pv_eoi_enabled(vcpu)); - pending = pv_eoi_get_pending(vcpu); - /* - * 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. - */ - pv_eoi_clr_pending(vcpu); - if (pending) + + if (pv_eoi_test_and_clr_pending(vcpu)) return; vector = apic_set_eoi(apic); trace_kvm_pv_eoi(apic, vector); @@ -2783,94 +3374,102 @@ int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr) return 0; } -int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data) +static int kvm_lapic_msr_read(struct kvm_lapic *apic, u32 reg, u64 *data) { - struct kvm_lapic *apic = vcpu->arch.apic; - u32 reg = (msr - APIC_BASE_MSR) << 4; + u32 low; - if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic)) - return 1; + if (reg == APIC_ICR) { + *data = kvm_x2apic_icr_read(apic); + return 0; + } - if (reg == APIC_ICR2) + if (kvm_lapic_reg_read(apic, reg, 4, &low)) return 1; - /* if this is ICR write vector before command */ + *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) - kvm_lapic_reg_write(apic, APIC_ICR2, (u32)(data >> 32)); + 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_read(struct kvm_vcpu *vcpu, u32 msr, u64 *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, low, high = 0; + u32 reg = (msr - APIC_BASE_MSR) << 4; if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic)) return 1; - if (reg == APIC_DFR || reg == APIC_ICR2) - return 1; + return kvm_lapic_msr_write(apic, reg, data); +} - if (kvm_lapic_reg_read(apic, reg, 4, &low)) - return 1; - if (reg == APIC_ICR) - kvm_lapic_reg_read(apic, APIC_ICR2, 4, &high); +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; - *data = (((u64)high) << 32) | low; + if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic)) + return 1; - return 0; + return kvm_lapic_msr_read(apic, reg, data); } int kvm_hv_vapic_msr_write(struct kvm_vcpu *vcpu, u32 reg, u64 data) { - struct kvm_lapic *apic = vcpu->arch.apic; - if (!lapic_in_kernel(vcpu)) return 1; - /* if this is ICR write vector before command */ - if (reg == APIC_ICR) - kvm_lapic_reg_write(apic, APIC_ICR2, (u32)(data >> 32)); - return kvm_lapic_reg_write(apic, reg, (u32)data); + return kvm_lapic_msr_write(vcpu->arch.apic, reg, data); } int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data) { - struct kvm_lapic *apic = vcpu->arch.apic; - u32 low, high = 0; - if (!lapic_in_kernel(vcpu)) return 1; - if (kvm_lapic_reg_read(apic, reg, 4, &low)) - return 1; - if (reg == APIC_ICR) - kvm_lapic_reg_read(apic, APIC_ICR2, 4, &high); - - *data = (((u64)high) << 32) | low; - - return 0; + return kvm_lapic_msr_read(vcpu->arch.apic, reg, data); } -int kvm_lapic_enable_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len) +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; - vcpu->arch.pv_eoi.msr_val = data; - if (!pv_eoi_enabled(vcpu)) - return 0; + if (data & KVM_MSR_ENABLED) { + if (addr == ghc->gpa && len <= ghc->len) + new_len = ghc->len; + else + new_len = len; - 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 kvm_gfn_to_hva_cache_init(vcpu->kvm, ghc, addr, new_len); + return 0; } int kvm_apic_accept_events(struct kvm_vcpu *vcpu) @@ -2878,17 +3477,8 @@ int kvm_apic_accept_events(struct kvm_vcpu *vcpu) struct kvm_lapic *apic = vcpu->arch.apic; u8 sipi_vector; int r; - unsigned long pe; - - if (!lapic_in_kernel(vcpu)) - return 0; - /* - * Read pending events before calling the check_events - * callback. - */ - pe = smp_load_acquire(&apic->pending_events); - if (!pe) + if (!kvm_apic_has_pending_init_or_sipi(vcpu)) return 0; if (is_guest_mode(vcpu)) { @@ -2896,44 +3486,38 @@ int kvm_apic_accept_events(struct kvm_vcpu *vcpu) if (r < 0) return r == -EBUSY ? 0 : r; /* - * If an event has happened and caused a vmexit, - * we know INITs are latched and therefore - * we will not incorrectly deliver an APIC - * event instead of a vmexit. + * 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 latched while CPU is in specific states - * (SMM, VMX root mode, SVM with GIF=0). - * Because a CPU cannot be in these states immediately - * after it has processed an INIT signal (and thus in - * KVM_MP_STATE_INIT_RECEIVED state), just eat SIPIs - * and leave the INIT pending. + * 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_vcpu_latch_init(vcpu)) { + if (!kvm_apic_init_sipi_allowed(vcpu)) { WARN_ON_ONCE(vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED); - if (test_bit(KVM_APIC_SIPI, &pe)) - clear_bit(KVM_APIC_SIPI, &apic->pending_events); + clear_bit(KVM_APIC_SIPI, &apic->pending_events); return 0; } - if (test_bit(KVM_APIC_INIT, &pe)) { - clear_bit(KVM_APIC_INIT, &apic->pending_events); + 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; + kvm_set_mp_state(vcpu, KVM_MP_STATE_RUNNABLE); else - vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED; + kvm_set_mp_state(vcpu, KVM_MP_STATE_INIT_RECEIVED); } - if (test_bit(KVM_APIC_SIPI, &pe)) { - clear_bit(KVM_APIC_SIPI, &apic->pending_events); + 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; - kvm_x86_ops.vcpu_deliver_sipi_vector(vcpu, sipi_vector); - vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE; + kvm_x86_call(vcpu_deliver_sipi_vector)(vcpu, + sipi_vector); + kvm_set_mp_state(vcpu, KVM_MP_STATE_RUNNABLE); } } return 0; @@ -2942,5 +3526,7 @@ int kvm_apic_accept_events(struct kvm_vcpu *vcpu) 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)); } |