From 0115f9cbac61918363cbaf26c8521ff9176ccc35 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Tue, 29 Nov 2016 18:14:06 -0800 Subject: [PATCH] KVM: nVMX: generate non-true VMX MSRs based on true versions MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The "non-true" VMX capability MSRs can be generated from their "true" counterparts, by OR-ing the default1 bits. The default1 bits are fixed and defined in the SDM. Since we can generate the non-true VMX MSRs from the true versions, there's no need to store both in struct nested_vmx. This also lets userspace avoid having to restore the non-true MSRs. Note this does not preclude emulating MSR_IA32_VMX_BASIC[55]=0. To do so, we simply need to set all the default1 bits in the true MSRs (such that the true MSRs and the generated non-true MSRs are equal). Signed-off-by: David Matlack Suggested-by: Paolo Bonzini Signed-off-by: Radim Krčmář --- arch/x86/kvm/vmx.c | 45 +++++++++++++++++++-------------------------- 1 file changed, 19 insertions(+), 26 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 16a144d22033..9e055d89ffad 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -452,19 +452,21 @@ struct nested_vmx { u16 vpid02; u16 last_vpid; + /* + * We only store the "true" versions of the VMX capability MSRs. We + * generate the "non-true" versions by setting the must-be-1 bits + * according to the SDM. + */ u32 nested_vmx_procbased_ctls_low; u32 nested_vmx_procbased_ctls_high; - u32 nested_vmx_true_procbased_ctls_low; u32 nested_vmx_secondary_ctls_low; u32 nested_vmx_secondary_ctls_high; u32 nested_vmx_pinbased_ctls_low; u32 nested_vmx_pinbased_ctls_high; u32 nested_vmx_exit_ctls_low; u32 nested_vmx_exit_ctls_high; - u32 nested_vmx_true_exit_ctls_low; u32 nested_vmx_entry_ctls_low; u32 nested_vmx_entry_ctls_high; - u32 nested_vmx_true_entry_ctls_low; u32 nested_vmx_misc_low; u32 nested_vmx_misc_high; u32 nested_vmx_ept_caps; @@ -2740,9 +2742,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx) vmx->nested.nested_vmx_exit_ctls_high |= VM_EXIT_CLEAR_BNDCFGS; /* We support free control of debug control saving. */ - vmx->nested.nested_vmx_true_exit_ctls_low = - vmx->nested.nested_vmx_exit_ctls_low & - ~VM_EXIT_SAVE_DEBUG_CONTROLS; + vmx->nested.nested_vmx_exit_ctls_low &= ~VM_EXIT_SAVE_DEBUG_CONTROLS; /* entry controls */ rdmsr(MSR_IA32_VMX_ENTRY_CTLS, @@ -2761,9 +2761,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx) vmx->nested.nested_vmx_entry_ctls_high |= VM_ENTRY_LOAD_BNDCFGS; /* We support free control of debug control loading. */ - vmx->nested.nested_vmx_true_entry_ctls_low = - vmx->nested.nested_vmx_entry_ctls_low & - ~VM_ENTRY_LOAD_DEBUG_CONTROLS; + vmx->nested.nested_vmx_entry_ctls_low &= ~VM_ENTRY_LOAD_DEBUG_CONTROLS; /* cpu-based controls */ rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, @@ -2796,8 +2794,7 @@ static void nested_vmx_setup_ctls_msrs(struct vcpu_vmx *vmx) CPU_BASED_USE_MSR_BITMAPS; /* We support free control of CR3 access interception. */ - vmx->nested.nested_vmx_true_procbased_ctls_low = - vmx->nested.nested_vmx_procbased_ctls_low & + vmx->nested.nested_vmx_procbased_ctls_low &= ~(CPU_BASED_CR3_LOAD_EXITING | CPU_BASED_CR3_STORE_EXITING); /* secondary cpu-based controls */ @@ -2896,36 +2893,32 @@ static int vmx_get_vmx_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata) *pdata = vmx_control_msr( vmx->nested.nested_vmx_pinbased_ctls_low, vmx->nested.nested_vmx_pinbased_ctls_high); + if (msr_index == MSR_IA32_VMX_PINBASED_CTLS) + *pdata |= PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR; break; case MSR_IA32_VMX_TRUE_PROCBASED_CTLS: - *pdata = vmx_control_msr( - vmx->nested.nested_vmx_true_procbased_ctls_low, - vmx->nested.nested_vmx_procbased_ctls_high); - break; case MSR_IA32_VMX_PROCBASED_CTLS: *pdata = vmx_control_msr( vmx->nested.nested_vmx_procbased_ctls_low, vmx->nested.nested_vmx_procbased_ctls_high); + if (msr_index == MSR_IA32_VMX_PROCBASED_CTLS) + *pdata |= CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR; break; case MSR_IA32_VMX_TRUE_EXIT_CTLS: - *pdata = vmx_control_msr( - vmx->nested.nested_vmx_true_exit_ctls_low, - vmx->nested.nested_vmx_exit_ctls_high); - break; case MSR_IA32_VMX_EXIT_CTLS: *pdata = vmx_control_msr( vmx->nested.nested_vmx_exit_ctls_low, vmx->nested.nested_vmx_exit_ctls_high); + if (msr_index == MSR_IA32_VMX_EXIT_CTLS) + *pdata |= VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR; break; case MSR_IA32_VMX_TRUE_ENTRY_CTLS: - *pdata = vmx_control_msr( - vmx->nested.nested_vmx_true_entry_ctls_low, - vmx->nested.nested_vmx_entry_ctls_high); - break; case MSR_IA32_VMX_ENTRY_CTLS: *pdata = vmx_control_msr( vmx->nested.nested_vmx_entry_ctls_low, vmx->nested.nested_vmx_entry_ctls_high); + if (msr_index == MSR_IA32_VMX_ENTRY_CTLS) + *pdata |= VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR; break; case MSR_IA32_VMX_MISC: *pdata = vmx_control_msr( @@ -10071,7 +10064,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) } if (!vmx_control_verify(vmcs12->cpu_based_vm_exec_control, - vmx->nested.nested_vmx_true_procbased_ctls_low, + vmx->nested.nested_vmx_procbased_ctls_low, vmx->nested.nested_vmx_procbased_ctls_high) || !vmx_control_verify(vmcs12->secondary_vm_exec_control, vmx->nested.nested_vmx_secondary_ctls_low, @@ -10080,10 +10073,10 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) vmx->nested.nested_vmx_pinbased_ctls_low, vmx->nested.nested_vmx_pinbased_ctls_high) || !vmx_control_verify(vmcs12->vm_exit_controls, - vmx->nested.nested_vmx_true_exit_ctls_low, + vmx->nested.nested_vmx_exit_ctls_low, vmx->nested.nested_vmx_exit_ctls_high) || !vmx_control_verify(vmcs12->vm_entry_controls, - vmx->nested.nested_vmx_true_entry_ctls_low, + vmx->nested.nested_vmx_entry_ctls_low, vmx->nested.nested_vmx_entry_ctls_high)) { nested_vmx_failValid(vcpu, VMXERR_ENTRY_INVALID_CONTROL_FIELD); -- 2.20.1