KVM: x86: Fix misleading comments on handling pending exceptions (a042c26f) · Commits · 戴 / test

The reason that exception.pending should block re-injection of NMI/interrupt is not described correctly in comment in code. Instead, it describes why a pending exception should be injected before a pending NMI/interrupt. Therefore, move currently present comment to code-block evaluating a new pending event which explains why exception.pending is evaluated first. In addition, create a new comment describing that exception.pending blocks re-injection of NMI/interrupt because the exception was queued by handling vmexit which was due to NMI/interrupt delivery. Signed-off-by:

Liran Alon <liran.alon@oracle.com> Reviewed-by:

Nikita Leshenko <nikita.leshchenko@oracle.com> Signed-off-by:

Krish Sadhukhan <krish.sadhukhan@orcle.com> [Used a comment from Sean J <sean.j.christopherson@intel.com>. - Radim] Signed-off-by:

Radim Krčmář <rkrcmar@redhat.com>

arch/x86/kvm/x86.c

+12 −2

Original line number	Diff line number	Diff line
		@@ -6758,8 +6758,18 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool req_int_win)
		}

		/*
		* Exceptions must be injected immediately, or the exception
		* frame will have the address of the NMI or interrupt handler.
		* Do not inject an NMI or interrupt if there is a pending
		* exception. Exceptions and interrupts are recognized at
		* instruction boundaries, i.e. the start of an instruction.
		* Trap-like exceptions, e.g. #DB, have higher priority than
		* NMIs and interrupts, i.e. traps are recognized before an
		* NMI/interrupt that's pending on the same instruction.
		* Fault-like exceptions, e.g. #GP and #PF, are the lowest
		* priority, but are only generated (pended) during instruction
		* execution, i.e. a pending fault-like exception means the
		* fault occurred on the previous instruction and must be
		* serviced prior to recognizing any new events in order to
		* fully complete the previous instruction.
		*/
		if (!vcpu->arch.exception.pending) {
		if (vcpu->arch.nmi_injected) {

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