diff options
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 71 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.h | 2 |
3 files changed, 24 insertions, 51 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 486789dac515..614b789ecf16 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -1075,16 +1075,12 @@ static bool nested_vmx_get_vmexit_msr_value(struct kvm_vcpu *vcpu, * 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 i = vmx_find_loadstore_msr_slot(&vmx->msr_autostore, - MSR_IA32_TSC); + if (msr_index == MSR_IA32_TSC && vmx->nested.tsc_autostore_slot >= 0) { + int slot = vmx->nested.tsc_autostore_slot; + u64 host_tsc = vmx->msr_autostore.val[slot].value; - if (i >= 0) { - u64 val = vmx->msr_autostore.val[i].value; - - *data = kvm_read_l1_tsc(vcpu, val); - return true; - } + *data = kvm_read_l1_tsc(vcpu, host_tsc); + return true; } if (kvm_emulate_msr_read(vcpu, msr_index, data)) { @@ -1163,42 +1159,6 @@ static bool nested_msr_store_list_has_msr(struct kvm_vcpu *vcpu, u32 msr_index) 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; - bool in_vmcs12_store_list; - int msr_autostore_slot; - bool in_autostore_list; - int last; - - msr_autostore_slot = vmx_find_loadstore_msr_slot(autostore, msr_index); - in_autostore_list = msr_autostore_slot >= 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 == MAX_NR_LOADSTORE_MSRS) { - /* - * Emulated VMEntry does not fail here. Instead a less - * accurate value will be returned by - * nested_vmx_get_vmexit_msr_value() by reading KVM's - * internal MSR state 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_slot] = autostore->val[last]; - } -} - /* * Load guest's/host's cr3 at nested entry/exit. @nested_ept is true if we are * emulating VM-Entry into a guest with EPT enabled. On failure, the expected @@ -2699,12 +2659,25 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) } /* - * Make sure the msr_autostore list is up to date before we set the - * count in the vmcs02. + * If vmcs12 is configured to save TSC on exit via the auto-store list, + * append the MSR to vmcs02's auto-store list so that KVM effectively + * reads TSC at the time of VM-Exit from L2. The saved value will be + * propagated to vmcs12's list on nested VM-Exit. + * + * Don't increment the number of MSRs in the vCPU structure, as saving + * TSC is specific to this particular incarnation of vmcb02, i.e. must + * not bleed into vmcs01. */ - prepare_vmx_msr_autostore_list(&vmx->vcpu, MSR_IA32_TSC); + if (nested_msr_store_list_has_msr(&vmx->vcpu, MSR_IA32_TSC) && + !WARN_ON_ONCE(vmx->msr_autostore.nr >= ARRAY_SIZE(vmx->msr_autostore.val))) { + vmx->nested.tsc_autostore_slot = vmx->msr_autostore.nr; + vmx->msr_autostore.val[vmx->msr_autostore.nr].index = MSR_IA32_TSC; - vmcs_write32(VM_EXIT_MSR_STORE_COUNT, vmx->msr_autostore.nr); + vmcs_write32(VM_EXIT_MSR_STORE_COUNT, vmx->msr_autostore.nr + 1); + } else { + vmx->nested.tsc_autostore_slot = -1; + vmcs_write32(VM_EXIT_MSR_STORE_COUNT, vmx->msr_autostore.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 23c92c41fd83..52bcb817cc15 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1029,7 +1029,7 @@ static __always_inline void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx vm_exit_controls_clearbit(vmx, exit); } -int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr) +static int vmx_find_loadstore_msr_slot(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 4ce653d729ca..3175fedb5a4d 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -191,6 +191,7 @@ struct nested_vmx { u16 vpid02; u16 last_vpid; + int tsc_autostore_slot; struct nested_vmx_msrs msrs; /* SMM related state */ @@ -383,7 +384,6 @@ void vmx_spec_ctrl_restore_host(struct vcpu_vmx *vmx, unsigned int flags); unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx); bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, unsigned int flags); -int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr); void vmx_ept_load_pdptrs(struct kvm_vcpu *vcpu); void vmx_set_intercept_for_msr(struct kvm_vcpu *vcpu, u32 msr, int type, bool set); |