diff options
36 files changed, 1425 insertions, 632 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index d3791a14eb9a..bb8cfddbb22d 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -5545,8 +5545,8 @@ the trailing ``'\0'``, is indicated by ``name_size`` in the header. The Stats Data block contains an array of 64-bit values in the same order as the descriptors in Descriptors block. -4.42 KVM_GET_XSAVE2 ------------------- +4.134 KVM_GET_XSAVE2 +-------------------- :Capability: KVM_CAP_XSAVE2 :Architectures: x86 @@ -7363,7 +7363,7 @@ trap and emulate MSRs that are outside of the scope of KVM as well as limit the attack surface on KVM's MSR emulation code. 8.28 KVM_CAP_ENFORCE_PV_FEATURE_CPUID ------------------------------ +------------------------------------- Architectures: x86 diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index f658bb4dbb74..631d5040b31e 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -55,6 +55,7 @@ KVM_X86_OP_NULL(tlb_remote_flush) KVM_X86_OP_NULL(tlb_remote_flush_with_range) KVM_X86_OP(tlb_flush_gva) KVM_X86_OP(tlb_flush_guest) +KVM_X86_OP(vcpu_pre_run) KVM_X86_OP(run) KVM_X86_OP_NULL(handle_exit) KVM_X86_OP_NULL(skip_emulated_instruction) @@ -98,8 +99,6 @@ KVM_X86_OP(handle_exit_irqoff) KVM_X86_OP_NULL(request_immediate_exit) KVM_X86_OP(sched_in) KVM_X86_OP_NULL(update_cpu_dirty_logging) -KVM_X86_OP_NULL(pre_block) -KVM_X86_OP_NULL(post_block) KVM_X86_OP_NULL(vcpu_blocking) KVM_X86_OP_NULL(vcpu_unblocking) KVM_X86_OP_NULL(update_pi_irte) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 0677b9ea01c9..1384517d7709 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1381,6 +1381,7 @@ struct kvm_x86_ops { */ void (*tlb_flush_guest)(struct kvm_vcpu *vcpu); + int (*vcpu_pre_run)(struct kvm_vcpu *vcpu); enum exit_fastpath_completion (*run)(struct kvm_vcpu *vcpu); int (*handle_exit)(struct kvm_vcpu *vcpu, enum exit_fastpath_completion exit_fastpath); @@ -1454,18 +1455,6 @@ struct kvm_x86_ops { const struct kvm_pmu_ops *pmu_ops; const struct kvm_x86_nested_ops *nested_ops; - /* - * Architecture specific hooks for vCPU blocking due to - * HLT instruction. - * Returns for .pre_block(): - * - 0 means continue to block the vCPU. - * - 1 means we cannot block the vCPU since some event - * happens during this period, such as, 'ON' bit in - * posted-interrupts descriptor is set. - */ - int (*pre_block)(struct kvm_vcpu *vcpu); - void (*post_block)(struct kvm_vcpu *vcpu); - void (*vcpu_blocking)(struct kvm_vcpu *vcpu); void (*vcpu_unblocking)(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index c55e57b30e81..3902c28fb6cb 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -119,6 +119,28 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu, return fpu_enable_guest_xfd_features(&vcpu->arch.guest_fpu, xfeatures); } +/* Check whether the supplied CPUID data is equal to what is already set for the vCPU. */ +static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, + int nent) +{ + struct kvm_cpuid_entry2 *orig; + int i; + + if (nent != vcpu->arch.cpuid_nent) + return -EINVAL; + + for (i = 0; i < nent; i++) { + orig = &vcpu->arch.cpuid_entries[i]; + if (e2[i].function != orig->function || + e2[i].index != orig->index || + e2[i].eax != orig->eax || e2[i].ebx != orig->ebx || + e2[i].ecx != orig->ecx || e2[i].edx != orig->edx) + return -EINVAL; + } + + return 0; +} + static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu) { u32 function; @@ -145,14 +167,21 @@ static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu) } } -static struct kvm_cpuid_entry2 *kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu) +static struct kvm_cpuid_entry2 *__kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu, + struct kvm_cpuid_entry2 *entries, int nent) { u32 base = vcpu->arch.kvm_cpuid_base; if (!base) return NULL; - return kvm_find_cpuid_entry(vcpu, base | KVM_CPUID_FEATURES, 0); + return cpuid_entry2_find(entries, nent, base | KVM_CPUID_FEATURES, 0); +} + +static struct kvm_cpuid_entry2 *kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu) +{ + return __kvm_find_kvm_cpuid_features(vcpu, vcpu->arch.cpuid_entries, + vcpu->arch.cpuid_nent); } void kvm_update_pv_runtime(struct kvm_vcpu *vcpu) @@ -167,11 +196,12 @@ void kvm_update_pv_runtime(struct kvm_vcpu *vcpu) vcpu->arch.pv_cpuid.features = best->eax; } -void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) +static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries, + int nent) { struct kvm_cpuid_entry2 *best; - best = kvm_find_cpuid_entry(vcpu, 1, 0); + best = cpuid_entry2_find(entries, nent, 1, 0); if (best) { /* Update OSXSAVE bit */ if (boot_cpu_has(X86_FEATURE_XSAVE)) @@ -182,33 +212,38 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE); } - best = kvm_find_cpuid_entry(vcpu, 7, 0); + best = cpuid_entry2_find(entries, nent, 7, 0); if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) cpuid_entry_change(best, X86_FEATURE_OSPKE, kvm_read_cr4_bits(vcpu, X86_CR4_PKE)); - best = kvm_find_cpuid_entry(vcpu, 0xD, 0); + best = cpuid_entry2_find(entries, nent, 0xD, 0); if (best) best->ebx = xstate_required_size(vcpu->arch.xcr0, false); - best = kvm_find_cpuid_entry(vcpu, 0xD, 1); + best = cpuid_entry2_find(entries, nent, 0xD, 1); if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || cpuid_entry_has(best, X86_FEATURE_XSAVEC))) best->ebx = xstate_required_size(vcpu->arch.xcr0, true); - best = kvm_find_kvm_cpuid_features(vcpu); + best = __kvm_find_kvm_cpuid_features(vcpu, entries, nent); if (kvm_hlt_in_guest(vcpu->kvm) && best && (best->eax & (1 << KVM_FEATURE_PV_UNHALT))) best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT); if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) { - best = kvm_find_cpuid_entry(vcpu, 0x1, 0); + best = cpuid_entry2_find(entries, nent, 0x1, 0); if (best) cpuid_entry_change(best, X86_FEATURE_MWAIT, vcpu->arch.ia32_misc_enable_msr & MSR_IA32_MISC_ENABLE_MWAIT); } } + +void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) +{ + __kvm_update_cpuid_runtime(vcpu, vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent); +} EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime); static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) @@ -298,6 +333,22 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, { int r; + __kvm_update_cpuid_runtime(vcpu, e2, nent); + + /* + * KVM does not correctly handle changing guest CPUID after KVM_RUN, as + * MAXPHYADDR, GBPAGES support, AMD reserved bit behavior, etc.. aren't + * tracked in kvm_mmu_page_role. As a result, KVM may miss guest page + * faults due to reusing SPs/SPTEs. In practice no sane VMM mucks with + * the core vCPU model on the fly. It would've been better to forbid any + * KVM_SET_CPUID{,2} calls after KVM_RUN altogether but unfortunately + * some VMMs (e.g. QEMU) reuse vCPU fds for CPU hotplug/unplug and do + * KVM_SET_CPUID{,2} again. To support this legacy behavior, check + * whether the supplied CPUID data is equal to what's already set. + */ + if (vcpu->arch.last_vmentry_cpu != -1) + return kvm_cpuid_check_equal(vcpu, e2, nent); + r = kvm_check_cpuid(vcpu, e2, nent); if (r) return r; @@ -307,7 +358,6 @@ static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, vcpu->arch.cpuid_nent = nent; kvm_update_kvm_cpuid_base(vcpu); - kvm_update_cpuid_runtime(vcpu); kvm_vcpu_after_set_cpuid(vcpu); return 0; @@ -795,10 +845,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) perf_get_x86_pmu_capability(&cap); /* - * Only support guest architectural pmu on a host - * with architectural pmu. + * The guest architecture pmu is only supported if the architecture + * pmu exists on the host and the module parameters allow it. */ - if (!cap.version) + if (!cap.version || !enable_pmu) memset(&cap, 0, sizeof(cap)); eax.split.version_id = min(cap.version, 2); @@ -886,6 +936,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) --array->nent; continue; } + + if (!kvm_cpu_cap_has(X86_FEATURE_XFD)) + entry->ecx &= ~BIT_ULL(2); entry->edx = 0; } break; diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index c5028e6b0f96..baca9fa37a91 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1950,7 +1950,6 @@ 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) { @@ -1962,7 +1961,6 @@ 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) { diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 1d275e9d76b5..593093b52395 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5756,6 +5756,7 @@ static bool __kvm_zap_rmaps(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) continue; flush = slot_handle_level_range(kvm, memslot, kvm_zap_rmapp, + PG_LEVEL_4K, KVM_MAX_HUGEPAGE_LEVEL, start, end - 1, true, flush); } @@ -5825,15 +5826,27 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, } /* - * We can flush all the TLBs out of the mmu lock without TLB - * corruption since we just change the spte from writable to - * readonly so that we only need to care the case of changing - * spte from present to present (changing the spte from present - * to nonpresent will flush all the TLBs immediately), in other - * words, the only case we care is mmu_spte_update() where we - * have checked Host-writable | MMU-writable instead of - * PT_WRITABLE_MASK, that means it does not depend on PT_WRITABLE_MASK - * anymore. + * Flush TLBs if any SPTEs had to be write-protected to ensure that + * guest writes are reflected in the dirty bitmap before the memslot + * update completes, i.e. before enabling dirty logging is visible to + * userspace. + * + * Perform the TLB flush outside the mmu_lock to reduce the amount of + * time the lock is held. However, this does mean that another CPU can + * now grab mmu_lock and encounter a write-protected SPTE while CPUs + * still have a writable mapping for the associated GFN in their TLB. + * + * This is safe but requires KVM to be careful when making decisions + * based on the write-protection status of an SPTE. Specifically, KVM + * also write-protects SPTEs to monitor changes to guest page tables + * during shadow paging, and must guarantee no CPUs can write to those + * page before the lock is dropped. As mentioned in the previous + * paragraph, a write-protected SPTE is no guarantee that CPU cannot + * perform writes. So to determine if a TLB flush is truly required, KVM + * will clear a separate software-only bit (MMU-writable) and skip the + * flush if-and-only-if this bit was already clear. + * + * See DEFAULT_SPTE_MMU_WRITEABLE for more details. */ if (flush) kvm_arch_flush_remote_tlbs_memslot(kvm, memslot); diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 351b04ad62a1..73cfe62fdad1 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -216,6 +216,7 @@ u64 kvm_mmu_changed_pte_notifier_make_spte(u64 old_spte, kvm_pfn_t new_pfn) new_spte &= ~PT_WRITABLE_MASK; new_spte &= ~shadow_host_writable_mask; + new_spte &= ~shadow_mmu_writable_mask; new_spte = mark_spte_for_access_track(new_spte); diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index a4af2a42695c..be6a007a4af3 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -60,10 +60,6 @@ static_assert(SPTE_TDP_AD_ENABLED_MASK == 0); (((address) >> PT64_LEVEL_SHIFT(level)) & ((1 << PT64_LEVEL_BITS) - 1)) #define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level) -/* Bits 9 and 10 are ignored by all non-EPT PTEs. */ -#define DEFAULT_SPTE_HOST_WRITEABLE BIT_ULL(9) -#define DEFAULT_SPTE_MMU_WRITEABLE BIT_ULL(10) - /* * The mask/shift to use for saving the original R/X bits when marking the PTE * as not-present for access tracking purposes. We do not save the W bit as the @@ -79,6 +75,35 @@ static_assert(SPTE_TDP_AD_ENABLED_MASK == 0); static_assert(!(SPTE_TDP_AD_MASK & SHADOW_ACC_TRACK_SAVED_MASK)); /* + * *_SPTE_HOST_WRITEABLE (aka Host-writable) indicates whether the host permits + * writes to the guest page mapped by the SPTE. This bit is cleared on SPTEs + * that map guest pages in read-only memslots and read-only VMAs. + * + * Invariants: + * - If Host-writable is clear, PT_WRITABLE_MASK must be clear. + * + * + * *_SPTE_MMU_WRITEABLE (aka MMU-writable) indicates whether the shadow MMU + * allows writes to the guest page mapped by the SPTE. This bit is cleared when + * the guest page mapped by the SPTE contains a page table that is being + * monitored for shadow paging. In this case the SPTE can only be made writable + * by unsyncing the shadow page under the mmu_lock. + * + * Invariants: + * - If MMU-writable is clear, PT_WRITABLE_MASK must be clear. + * - If MMU-writable is set, Host-writable must be set. + * + * If MMU-writable is set, PT_WRITABLE_MASK is normally set but can be cleared + * to track writes for dirty logging. For such SPTEs, KVM will locklessly set + * PT_WRITABLE_MASK upon the next write from the guest and record the write in + * the dirty log (see fast_page_fault()). + */ + +/* Bits 9 and 10 are ignored by all non-EPT PTEs. */ +#define DEFAULT_SPTE_HOST_WRITEABLE BIT_ULL(9) +#define DEFAULT_SPTE_MMU_WRITEABLE BIT_ULL(10) + +/* * Low ignored bits are at a premium for EPT, use high ignored bits, taking care * to not overlap the A/D type mask or the saved access bits of access-tracked * SPTEs when A/D bits are disabled. @@ -316,8 +341,13 @@ static __always_inline bool is_rsvd_spte(struct rsvd_bits_validate *rsvd_check, static inline bool spte_can_locklessly_be_made_writable(u64 spte) { - return (spte & shadow_host_writable_mask) && - (spte & shadow_mmu_writable_mask); + if (spte & shadow_mmu_writable_mask) { + WARN_ON_ONCE(!(spte & shadow_host_writable_mask)); + return true; + } + + WARN_ON_ONCE(spte & PT_WRITABLE_MASK); + return false; } static inline u64 get_mmio_spte_generation(u64 spte) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 7b1bc816b7c3..bc9e3553fba2 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1442,12 +1442,12 @@ static bool write_protect_gfn(struct kvm *kvm, struct kvm_mmu_page *root, !is_last_spte(iter.old_spte, iter.level)) continue; - if (!is_writable_pte(iter.old_spte)) - break; - new_spte = iter.old_spte & ~(PT_WRITABLE_MASK | shadow_mmu_writable_mask); + if (new_spte == iter.old_spte) + break; + tdp_mmu_set_spte(kvm, &iter, new_spte); spte_set = true; } diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 261b39cbef6e..f614f95acc6b 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -13,6 +13,8 @@ #include <linux/types.h> #include <linux/kvm_host.h> #include <linux/perf_event.h> +#include <linux/bsearch.h> +#include <linux/sort.h> #include <asm/perf_event.h> #include "x86.h" #include "cpuid.h" @@ -109,6 +111,9 @@ static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, .config = config, }; + if (type == PERF_TYPE_HARDWARE && config >= PERF_COUNT_HW_MAX) + return; + attr.sample_period = get_sample_period(pmc, pmc->counter); if (in_tx) @@ -169,12 +174,16 @@ static bool pmc_resume_counter(struct kvm_pmc *pmc) return true; } +static int cmp_u64(const void *a, const void *b) +{ + return *(__u64 *)a - *(__u64 *)b; +} + void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel) { unsigned config, type = PERF_TYPE_RAW; struct kvm *kvm = pmc->vcpu->kvm; struct kvm_pmu_event_filter *filter; - int i; bool allow_event = true; if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL) @@ -189,16 +198,13 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel) filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu); if (filter) { - for (i = 0; i < filter->nevents; i++) - if (filter->events[i] == - (eventsel & AMD64_RAW_EVENT_MASK_NB)) - break; - if (filter->action == KVM_PMU_EVENT_ALLOW && - i == filter->nevents) - allow_event = false; - if (filter->action == KVM_PMU_EVENT_DENY && - i < filter->nevents) - allow_event = false; + __u64 key = eventsel & AMD64_RAW_EVENT_MASK_NB; + + if (bsearch(&key, filter->events, filter->nevents, + sizeof(__u64), cmp_u64)) + allow_event = filter->action == KVM_PMU_EVENT_ALLOW; + else + allow_event = filter->action == KVM_PMU_EVENT_DENY; } if (!allow_event) return; @@ -573,6 +579,11 @@ int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp) /* Ensure nevents can't be changed between the user copies. */ *filter = tmp; + /* + * Sort the in-kernel list so that we can search it with bsearch. + */ + sort(&filter->events, filter->nevents, sizeof(__u64), cmp_u64, NULL); + mutex_lock(&kvm->lock); filter = rcu_replace_pointer(kvm->arch.pmu_event_filter, filter, mutex_is_locked(&kvm->lock)); diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c index 0e5b49294086..90364d02f22a 100644 --- a/arch/x86/kvm/svm/avic.c +++ b/arch/x86/kvm/svm/avic.c @@ -295,13 +295,16 @@ static void avic_kick_target_vcpus(struct kvm *kvm, struct kvm_lapic *source, struct kvm_vcpu *vcpu; unsigned long i; + /* + * Wake any target vCPUs that are blocking, i.e. waiting for a wake + * event. There's no need to signal doorbells, as hardware has handled + * vCPUs that were in guest at the time of the IPI, and vCPUs that have + * since entered the guest will have processed pending IRQs at VMRUN. + */ kvm_for_each_vcpu(i, vcpu, kvm) { - bool m = kvm_apic_match_dest(vcpu, source, - icrl & APIC_SHORT_MASK, - GET_APIC_DEST_FIELD(icrh), - icrl & APIC_DEST_MASK); - - if (m && !avic_vcpu_is_running(vcpu)) + if (kvm_apic_match_dest(vcpu, source, icrl & APIC_SHORT_MASK, + GET_APIC_DEST_FIELD(icrh), + icrl & APIC_DEST_MASK)) kvm_vcpu_wake_up(vcpu); } } @@ -672,9 +675,22 @@ int svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec) return -1; kvm_lapic_set_irr(vec, vcpu->arch.apic); + + /* + * Pairs with the smp_mb_*() after setting vcpu->guest_mode in + * vcpu_enter_guest() to ensure the write to the vIRR is ordered before + * the read of guest_mode, which guarantees that either VMRUN will see + * and process the new vIRR entry, or that the below code will signal + * the doorbell if the vCPU is already running in the guest. + */ smp_mb__after_atomic(); - if (avic_vcpu_is_running(vcpu)) { + /* + * Signal the doorbell to tell hardware to inject the IRQ if the vCPU + * is in the guest. If the vCPU is not in the guest, hardware will + * automatically process AVIC interrupts at VMRUN. + */ + if (vcpu->mode == IN_GUEST_MODE) { int cpu = READ_ONCE(vcpu->cpu); /* @@ -688,8 +704,13 @@ int svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec) if (cpu != get_cpu()) wrmsrl(SVM_AVIC_DOORBELL, kvm_cpu_get_apicid(cpu)); put_cpu(); - } else + } else { + /* + * Wake the vCPU if it was blocking. KVM will then detect the + * pending IRQ when checking if the vCPU has a wake event. + */ kvm_vcpu_wake_up(vcpu); + } return 0; } @@ -957,6 +978,8 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) int h_physical_id = kvm_cpu_get_apicid(cpu); struct vcpu_svm *svm = to_svm(vcpu); + lockdep_assert_preemption_disabled(); + /* * Since the host physical APIC id is 8 bits, * we can support host APIC ID upto 255. @@ -964,19 +987,25 @@ void avic_vcpu_load(struct kvm_vcpu *vcpu, int cpu) if (WARN_ON(h_physical_id > AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK)) return; + /* + * No need to update anything if the vCPU is blocking, i.e. if the vCPU + * is being scheduled in after being preempted. The CPU entries in the + * Physical APIC table and IRTE are consumed iff IsRun{ning} is '1'. + * If the vCPU was migrated, its new CPU value will be stuffed when the + * vCPU unblocks. + */ + if (kvm_vcpu_is_blocking(vcpu)) + return; + entry = READ_ONCE(*(svm->avic_physical_id_cache)); WARN_ON(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK); entry &= ~AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK; entry |= (h_physical_id & AVIC_PHYSICAL_ID_ENTRY_HOST_PHYSICAL_ID_MASK); - - entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; - if (svm->avic_is_running) - entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; + entry |= AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; WRITE_ONCE(*(svm->avic_physical_id_cache), entry); - avic_update_iommu_vcpu_affinity(vcpu, h_physical_id, - svm->avic_is_running); + avic_update_iommu_vcpu_affinity(vcpu, h_physical_id, true); } void avic_vcpu_put(struct kvm_vcpu *vcpu) @@ -984,42 +1013,56 @@ void avic_vcpu_put(struct kvm_vcpu *vcpu) u64 entry; struct vcpu_svm *svm = to_svm(vcpu); + lockdep_assert_preemption_disabled(); + entry = READ_ONCE(*(svm->avic_physical_id_cache)); - if (entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK) - avic_update_iommu_vcpu_affinity(vcpu, -1, 0); + + /* Nothing to do if IsRunning == '0' due to vCPU blocking. */ + if (!(entry & AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK)) + return; + + avic_update_iommu_vcpu_affinity(vcpu, -1, 0); entry &= ~AVIC_PHYSICAL_ID_ENTRY_IS_RUNNING_MASK; WRITE_ONCE(*(svm->avic_physical_id_cache), entry); } -/* - * This function is called during VCPU halt/unhalt. - */ -static void avic_set_running(struct kvm_vcpu *vcpu, bool is_run) +void avic_vcpu_blocking(struct kvm_vcpu *vcpu) { - struct vcpu_svm *svm = to_svm(vcpu); - int cpu = get_cpu(); - - WARN_ON(cpu != vcpu->cpu); - svm->avic_is_running = is_run; + if (!kvm_vcpu_apicv_active(vcpu)) + return; - if (kvm_vcpu_apicv_active(vcpu)) { - if (is_run) - avic_vcpu_load(vcpu, cpu); - else - avic_vcpu_put(vcpu); - } - put_cpu(); + preempt_disable(); + + /* + * Unload the AVIC when the vCPU is about to block, _before_ + * the vCPU actually blocks. + * + * Any IRQs that arrive before IsRunning=0 will not cause an + * incomplete IPI vmexit on the source, therefore vIRR will also + * be checked by kvm_vcpu_check_block() before blocking. The + * memory barrier implicit in set_current_state orders writing + * IsRunning=0 before reading the vIRR. The processor needs a + * matching memory barrier on interrupt delivery between writing + * IRR and reading IsRunning; the lack of this barrier might be + * the cause of errata #1235). + */ + avic_vcpu_put(vcpu); + + preempt_enable(); } -void svm_vcpu_blocking(struct kvm_vcpu *vcpu) +void avic_vcpu_unblocking(struct kvm_vcpu *vcpu) { - avic_set_running(vcpu, false); -} + int cpu; -void svm_vcpu_unblocking(struct kvm_vcpu *vcpu) -{ - if (kvm_check_request(KVM_REQ_APICV_UPDATE, vcpu)) - kvm_vcpu_update_apicv(vcpu); - avic_set_running(vcpu, true); + if (!kvm_vcpu_apicv_active(vcpu)) + return; + + cpu = get_cpu(); + WARN_ON(cpu != vcpu->cpu); + + avic_vcpu_load(vcpu, cpu); + + put_cpu(); } diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c index 12d8b301065a..5aa45f13b16d 100644 --- a/arch/x86/kvm/svm/pmu.c +++ b/arch/x86/kvm/svm/pmu.c @@ -101,7 +101,7 @@ static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr, { struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu); - if (!pmu) + if (!enable_pmu) return NULL; switch (msr) { diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 46bcc706f257..2c99b18d76c0 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -192,10 +192,6 @@ module_param(vgif, int, 0444); static int lbrv = true; module_param(lbrv, int, 0444); -/* enable/disable PMU virtualization */ -bool pmu = true; -module_param(pmu, bool, 0444); - static int tsc_scaling = true; module_param(tsc_scaling, int, 0444); @@ -873,47 +869,6 @@ static void shrink_ple_window(struct kvm_vcpu *vcpu) } } -/* - * The default MMIO mask is a single bit (excluding the present bit), - * which could conflict with the memory encryption bit. Check for - * memory encryption support and override the default MMIO mask if - * memory encryption is enabled. - */ -static __init void svm_adjust_mmio_mask(void) -{ - unsigned int enc_bit, mask_bit; - u64 msr, mask; - - /* If there is no memory encryption support, use existing mask */ - if (cpuid_eax(0x80000000) < 0x8000001f) - return; - - /* If memory encryption is not enabled, use existing mask */ - rdmsrl(MSR_AMD64_SYSCFG, msr); - if (!(msr & MSR_AMD64_SYSCFG_MEM_ENCRYPT)) - return; - - enc_bit = cpuid_ebx(0x8000001f) & 0x3f; - mask_bit = boot_cpu_data.x86_phys_bits; - - /* Increment the mask bit if it is the same as the encryption bit */ - if (enc_bit == mask_bit) - mask_bit++; - - /* - * If the mask bit location is below 52, then some bits above the - * physical addressing limit will always be reserved, so use the - * rsvd_bits() function to generate the mask. This mask, alo |