[PATCH v2 1/2] KVM: SVM: Allow KVM_SET_NESTED_STATE to clear GIF when SVME==0

Jim Mattson
2025-10-09T22:32:50Z

GIF==0 together with EFER.SVME==0 is a valid architectural
state. Don't return -EINVAL for KVM_SET_NESTED_STATE when this
combination is specified.

Fixes: cc440cdad5b7 ("KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE")
Signed-off-by: Jim Mattson <jmattson@google.com>
---
arch/x86/kvm/svm/nested.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index a6443feab252..db0d4f2b128c 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1798,8 +1798,8 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
* EFER.SVME, but EFER.SVME still has to be 1 for VMRUN to succeed.
*/
if (!(vcpu->arch.efer & EFER_SVME)) {
- /* GIF=1 and no guest mode are required if SVME=0. */
- if (kvm_state->flags != KVM_STATE_NESTED_GIF_SET)
+ /* GUEST_MODE must be clear when SVME==0 */
+ if (kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE)
return -EINVAL;
}

--
2.51.0.740.g6adb054d12-goog