Commit c513f484 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

KVM: nSVM: leave guest mode when clearing EFER.SVME 



According to the AMD manual, the effect of turning off EFER.SVME while a
guest is running is undefined.  We make it leave guest mode immediately,
similar to the effect of clearing the VMX bit in MSR_IA32_FEAT_CTL.

Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent ca46d739

arch/x86/kvm/svm/nested.c

+16 −0
Original line number Diff line number Diff line
@@ -618,6 +618,22 @@ int nested_svm_vmexit(struct vcpu_svm *svm) 
	return 0;

}



/*

 * Forcibly leave nested mode in order to be able to reset the VCPU later on.

 */

void svm_leave_nested(struct vcpu_svm *svm)

{

	if (is_guest_mode(&svm->vcpu)) {

		struct vmcb *hsave = svm->nested.hsave;

		struct vmcb *vmcb = svm->vmcb;



		svm->nested.nested_run_pending = 0;

		leave_guest_mode(&svm->vcpu);

		copy_vmcb_control_area(&vmcb->control, &hsave->control);

		nested_svm_uninit_mmu_context(&svm->vcpu);

	}

}



static int nested_svm_exit_handled_msr(struct vcpu_svm *svm)

{

	u32 offset, msr, value;

arch/x86/kvm/svm/svm.c

+8 −2
Original line number Diff line number Diff line
@@ -265,6 +265,7 @@ static int get_npt_level(struct kvm_vcpu *vcpu) 


void svm_set_efer(struct kvm_vcpu *vcpu, u64 efer)

{

	struct vcpu_svm *svm = to_svm(vcpu);

	vcpu->arch.efer = efer;



	if (!npt_enabled) {
@@ -275,8 +276,13 @@ void svm_set_efer(struct kvm_vcpu *vcpu, u64 efer) 
			efer &= ~EFER_LME;

	}



	to_svm(vcpu)->vmcb->save.efer = efer | EFER_SVME;

	mark_dirty(to_svm(vcpu)->vmcb, VMCB_CR);

	if (!(efer & EFER_SVME)) {

		svm_leave_nested(svm);

		svm_set_gif(svm, true);

	}



	svm->vmcb->save.efer = efer | EFER_SVME;

	mark_dirty(svm->vmcb, VMCB_CR);

}



static int is_external_interrupt(u32 info)

arch/x86/kvm/svm/svm.h

+1 −0
Original line number Diff line number Diff line
@@ -389,6 +389,7 @@ static inline bool nested_exit_on_nmi(struct vcpu_svm *svm) 


void enter_svm_guest_mode(struct vcpu_svm *svm, u64 vmcb_gpa,

			  struct vmcb *nested_vmcb);

void svm_leave_nested(struct vcpu_svm *svm);

int nested_svm_vmrun(struct vcpu_svm *svm);

void nested_svm_vmloadsave(struct vmcb *from_vmcb, struct vmcb *to_vmcb);

int nested_svm_vmexit(struct vcpu_svm *svm);

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