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SubjectRe: [PATCH] KVM: nSVM: check for EFER.SVME=1 before entering guest
Date
Paolo Bonzini <pbonzini@redhat.com> writes:

> EFER is set for L2 using svm_set_efer, which hardcodes EFER_SVME to 1 and hides
> an incorrect value for EFER.SVME in the L1 VMCB. Perform the check manually
> to detect invalid guest state.
>
> Reported-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/kvm/svm.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 08568ae9f7a1..2125c6ae5951 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -3558,6 +3558,9 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
>
> static bool nested_vmcb_checks(struct vmcb *vmcb)
> {
> + if ((vmcb->save.efer & EFER_SVME) == 0)
> + return false;
> +
> if ((vmcb->control.intercept & (1ULL << INTERCEPT_VMRUN)) == 0)
> return false;

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>

--
Vitaly

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