[RFC PATCH 07/22] KVM: nSVM: Nested #VMEXIT may transition from HALTED to RUNNABLE

Mingwei Zhang
2024-11-21T18:53:30Z

From: Jim Mattson <jmattson@google.com>

When a halted vCPU is awakened by a nested event, it might have been
the target of a previous KVM_HC_KICK_CPU hypercall, in which case
pv_unhalted would be set. This flag should be cleared before the next
HLT instruction, as kvm_vcpu_has_events() would otherwise return true
and prevent the vCPU from entering the halt state.

Use kvm_vcpu_make_runnable() to ensure consistent handling of the
HALTED to RUNNABLE state transition.

Fixes: 38c0b192bd6d ("KVM: SVM: leave halted state on vmexit")
Signed-off-by: Jim Mattson <jmattson@google.com>
---
arch/x86/kvm/svm/nested.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index cf84103ce38b9..49e6cdfeac4da 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -994,7 +994,7 @@ int nested_svm_vmexit(struct vcpu_svm *svm)
kvm_clear_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu);

/* in case we halted in L2 */
- svm->vcpu.arch.mp_state = KVM_MP_STATE_RUNNABLE;
+ kvm_vcpu_make_runnable(vcpu);

/* Give the current vmcb to the guest */

--
2.47.0.371.ga323438b13-goog