diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 3ef529cc72fb..60d42ce42403 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -940,6 +940,37 @@ fail: return i + 1; } +static bool nested_vmx_get_vmexit_msr_value(struct kvm_vcpu *vcpu, + u32 msr_index, + u64 *data) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + + /* + * If the L0 hypervisor stored a more accurate value for the TSC that + * does not include the time taken for emulation of the L2->L1 + * VM-exit in L0, use the more accurate value. + */ + if (msr_index == MSR_IA32_TSC) { + int index = vmx_find_msr_index(&vmx->msr_autostore.guest, + MSR_IA32_TSC); + + if (index >= 0) { + u64 val = vmx->msr_autostore.guest.val[index].value; + + *data = kvm_read_l1_tsc(vcpu, val); + return true; + } + } + + if (kvm_get_msr(vcpu, msr_index, data)) { + pr_debug_ratelimited("%s cannot read MSR (0x%x)\n", __func__, + msr_index); + return false; + } + return true; +} + static bool read_and_check_msr_entry(struct kvm_vcpu *vcpu, u64 gpa, int i, struct vmx_msr_entry *e) { @@ -974,12 +1005,9 @@ static int nested_vmx_store_msr(struct kvm_vcpu *vcpu, u64 gpa, u32 count) if (!read_and_check_msr_entry(vcpu, gpa, i, &e)) return -EINVAL; - if (kvm_get_msr(vcpu, e.index, &data)) { - pr_debug_ratelimited( - "%s cannot read MSR (%u, 0x%x)\n", - __func__, i, e.index); + if (!nested_vmx_get_vmexit_msr_value(vcpu, e.index, &data)) return -EINVAL; - } + if (kvm_vcpu_write_guest(vcpu, gpa + i * sizeof(e) + offsetof(struct vmx_msr_entry, value), @@ -993,6 +1021,60 @@ static int nested_vmx_store_msr(struct kvm_vcpu *vcpu, u64 gpa, u32 count) return 0; } +static bool nested_msr_store_list_has_msr(struct kvm_vcpu *vcpu, u32 msr_index) +{ + struct vmcs12 *vmcs12 = get_vmcs12(vcpu); + u32 count = vmcs12->vm_exit_msr_store_count; + u64 gpa = vmcs12->vm_exit_msr_store_addr; + struct vmx_msr_entry e; + u32 i; + + for (i = 0; i < count; i++) { + if (!read_and_check_msr_entry(vcpu, gpa, i, &e)) + return false; + + if (e.index == msr_index) + return true; + } + return false; +} + +static void prepare_vmx_msr_autostore_list(struct kvm_vcpu *vcpu, + u32 msr_index) +{ + struct vcpu_vmx *vmx = to_vmx(vcpu); + struct vmx_msrs *autostore = &vmx->msr_autostore.guest; + bool in_vmcs12_store_list; + int msr_autostore_index; + bool in_autostore_list; + int last; + + msr_autostore_index = vmx_find_msr_index(autostore, msr_index); + in_autostore_list = msr_autostore_index >= 0; + in_vmcs12_store_list = nested_msr_store_list_has_msr(vcpu, msr_index); + + if (in_vmcs12_store_list && !in_autostore_list) { + if (autostore->nr == NR_LOADSTORE_MSRS) { + /* + * Emulated VMEntry does not fail here. Instead a less + * accurate value will be returned by + * nested_vmx_get_vmexit_msr_value() using kvm_get_msr() + * instead of reading the value from the vmcs02 VMExit + * MSR-store area. + */ + pr_warn_ratelimited( + "Not enough msr entries in msr_autostore. Can't add msr %x\n", + msr_index); + return; + } + last = autostore->nr++; + autostore->val[last].index = msr_index; + } else if (!in_vmcs12_store_list && in_autostore_list) { + last = --autostore->nr; + autostore->val[msr_autostore_index] = autostore->val[last]; + } +} + static bool nested_cr3_valid(struct kvm_vcpu *vcpu, unsigned long val) { unsigned long invalid_mask; @@ -2038,7 +2120,7 @@ static void prepare_vmcs02_constant_state(struct vcpu_vmx *vmx) * addresses are constant (for vmcs02), the counts can change based * on L2's behavior, e.g. switching to/from long mode. */ - vmcs_write32(VM_EXIT_MSR_STORE_COUNT, 0); + vmcs_write64(VM_EXIT_MSR_STORE_ADDR, __pa(vmx->msr_autostore.guest.val)); vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host.val)); vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest.val)); @@ -2306,6 +2388,13 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) vmcs_write64(EOI_EXIT_BITMAP3, vmcs12->eoi_exit_bitmap3); } + /* + * Make sure the msr_autostore list is up to date before we set the + * count in the vmcs02. + */ + prepare_vmx_msr_autostore_list(&vmx->vcpu, MSR_IA32_TSC); + + vmcs_write32(VM_EXIT_MSR_STORE_COUNT, vmx->msr_autostore.guest.nr); vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr); vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 7b191963dde1..621142e55e28 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -833,7 +833,7 @@ static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx, vm_exit_controls_clearbit(vmx, exit); } -static int vmx_find_msr_index(struct vmx_msrs *m, u32 msr) +int vmx_find_msr_index(struct vmx_msrs *m, u32 msr) { unsigned int i; diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index 73ff03091d29..90b97d9d4f7d 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -233,6 +233,10 @@ struct vcpu_vmx { struct vmx_msrs host; } msr_autoload; + struct msr_autostore { + struct vmx_msrs guest; + } msr_autostore; + struct { int vm86_active; ulong save_rflags; @@ -337,6 +341,7 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu); struct shared_msr_entry *find_msr_entry(struct vcpu_vmx *vmx, u32 msr); void pt_update_intercept_for_msr(struct vcpu_vmx *vmx); void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp); +int vmx_find_msr_index(struct vmx_msrs *m, u32 msr); #define POSTED_INTR_ON 0 #define POSTED_INTR_SN 1