Commit 699a1ac2 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: nVMX: Update vmcs12 for MSR_IA32_DEBUGCTLMSR when it's written 



KVM unconditionally intercepts WRMSR to MSR_IA32_DEBUGCTLMSR.  In the
unlikely event that L1 allows L2 to write L1's MSR_IA32_DEBUGCTLMSR, but
but saves L2's value on VM-Exit, update vmcs12 during L2's WRMSR so as
to eliminate the need to VMREAD the value from vmcs02 on nested VM-Exit.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent de70d279

arch/x86/kvm/vmx/nested.c

+1 −3
Original line number Diff line number Diff line
@@ -3563,10 +3563,8 @@ static void sync_vmcs02_to_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) 
		(vmcs12->vm_entry_controls & ~VM_ENTRY_IA32E_MODE) |

		(vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE);



	if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS) {

	if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_DEBUG_CONTROLS)

		kvm_get_dr(vcpu, 7, (unsigned long *)&vmcs12->guest_dr7);

		vmcs12->guest_ia32_debugctl = vmcs_read64(GUEST_IA32_DEBUGCTL);

	}



	if (vmcs12->vm_exit_controls & VM_EXIT_SAVE_IA32_EFER)

		vmcs12->guest_ia32_efer = vcpu->arch.efer;

arch/x86/kvm/vmx/vmx.c

+8 −0
Original line number Diff line number Diff line
@@ -1845,6 +1845,14 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 
			get_vmcs12(vcpu)->guest_sysenter_esp = data;

		vmcs_writel(GUEST_SYSENTER_ESP, data);

		break;

	case MSR_IA32_DEBUGCTLMSR:

		if (is_guest_mode(vcpu) && get_vmcs12(vcpu)->vm_exit_controls &

						VM_EXIT_SAVE_DEBUG_CONTROLS)

			get_vmcs12(vcpu)->guest_ia32_debugctl = data;



		ret = kvm_set_msr_common(vcpu, msr_info);

		break;



	case MSR_IA32_BNDCFGS:

		if (!kvm_mpx_supported() ||

		    (!msr_info->host_initiated &&