Commit 0115f9cb authored by David Matlack's avatar David Matlack Committed by Paolo Bonzini
Browse files

KVM: nVMX: generate non-true VMX MSRs based on true versions 



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: default avatarDavid Matlack <dmatlack@google.com>
Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent ea07e42d

arch/x86/kvm/vmx.c

+19 −26
Original line number Diff line number Diff line
@@ -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);

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