Commit 45405155 authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: x86: WARN if a vCPU gets a valid wakeup that KVM can't yet inject 

WARN if a blocking vCPU is awakened by a valid wake event that KVM can't
inject, e.g. because KVM needs to complete 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.

Link: https://lore.kernel.org/r/20240607172609.3205077-7-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 321ef62b

arch/x86/kvm/x86.c

+4 −1
Original line number Diff line number Diff line
@@ -11208,7 +11208,10 @@ 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;

	}