[PATCH 5/6] KVM: nSVM: always leave the nested state first on KVM_SET_NESTED_STATE

From: Maxim Levitsky
Date: Wed Jan 06 2021 - 05:52:17 EST


This should prevent bad things from happening if the user calls the
KVM_SET_NESTED_STATE twice.

Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index c1a3d0e996add..3aa18016832d0 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -1154,8 +1154,9 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
if (is_smm(vcpu) && (kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE))
return -EINVAL;

+ svm_leave_nested(svm);
+
if (!(kvm_state->flags & KVM_STATE_NESTED_GUEST_MODE)) {
- svm_leave_nested(svm);
svm_set_gif(svm, !!(kvm_state->flags & KVM_STATE_NESTED_GIF_SET));
return 0;
}
--
2.26.2