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Commit a0d4f803 authored by Krish Sadhukhan's avatar Krish Sadhukhan Committed by Paolo Bonzini
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KVM nVMX: MSRs should not be stored if VM-entry fails during or after loading guest state 



According to section "VM-entry Failures During or After Loading Guest State"
in Intel SDM vol 3C,

	"No MSRs are saved into the VM-exit MSR-store area."

when bit 31 of the exit reason is set.

Reported-by: default avatarKrish Sadhukhan <krish.sadhukhan@oracle.com>
Suggested-by: default avatarJim Mattson <jmattson@google.com>
Signed-off-by: default avatarKrish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: default avatarDarren Kenny <darren.kenny@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent e53d88af

arch/x86/kvm/vmx/nested.c

+12 −4
Original line number Diff line number Diff line
@@ -3504,6 +3504,18 @@ static void prepare_vmcs12(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 
		 * L2 to IDT_VECTORING_INFO_FIELD.

		 */

		vmcs12_save_pending_event(vcpu, vmcs12);



		/*

		 * According to spec, there's no need to store the guest's

		 * MSRs if the exit is due to a VM-entry failure that occurs

		 * during or after loading the guest state. Since this exit

		 * does not fall in that category, we need to save the MSRs.

		 */

		if (nested_vmx_store_msr(vcpu,

					 vmcs12->vm_exit_msr_store_addr,

					 vmcs12->vm_exit_msr_store_count))

			nested_vmx_abort(vcpu,

					 VMX_ABORT_SAVE_GUEST_MSR_FAIL);

	}



	/*
@@ -3835,10 +3847,6 @@ void nested_vmx_vmexit(struct kvm_vcpu *vcpu, u32 exit_reason, 
		 * immutable.

		 */

		nested_flush_cached_shadow_vmcs12(vcpu, vmcs12);



		if (nested_vmx_store_msr(vcpu, vmcs12->vm_exit_msr_store_addr,

					 vmcs12->vm_exit_msr_store_count))

			nested_vmx_abort(vcpu, VMX_ABORT_SAVE_GUEST_MSR_FAIL);

	} else {

		/*

		 * The only expected VM-instruction error is "VM entry with