WARN if a blocking vCPU is awaked by a valid wake event that KVM can't
inject, e.g. because KVM needs to completed a nested VM-enter, or needs to
re-inject an exception. For the nested VM-Enter case, KVM is supposed to
clear "nested_run_pending" if L1 puts L2 into HLT, i.e. entering HLT
"completes" the nested VM-Enter. And for already-injected exceptions, it
should be impossible for the vCPU to be in a blocking state if a VM-Exit
occurred while an exception was being vectored.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 82442960b499..f6ace2bd7124 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11233,7 +11233,10 @@ static inline int vcpu_block(struct kvm_vcpu *vcpu)
* causes a spurious wakeup from HLT).
*/
if (is_guest_mode(vcpu)) {
- if (kvm_check_nested_events(vcpu) < 0)
+ int r = kvm_check_nested_events(vcpu);
+
+ WARN_ON_ONCE(r == -EBUSY);
+ if (r < 0)
return 0;
}
--
2.45.2.505.gda0bf45e8d-goog
