linux-kernel - [PATCH 2/2] KVM: x86: Fix a comment inside __kvm_set_or_clear_apicv

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Message-ID: <e462e7001b8668649347f879c66597d3327dbac2.1728383775.git.kai.huang@intel.com>
Date: Tue,  8 Oct 2024 23:45:14 +1300
From: Kai Huang <kai.huang@...el.com>
To: pbonzini@...hat.com,
	seanjc@...gle.com,
	kvm@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
	Kai Huang <kai.huang@...el.com>
Subject: [PATCH 2/2] KVM: x86: Fix a comment inside __kvm_set_or_clear_apicv_inhibit()

Change svm_vcpu_run() to vcpu_enter_guest() in the comment of
__kvm_set_or_clear_apicv_inhibit() to make it reflect the fact.

When one thread updates VM's APICv state due to updating the APICv
inhibit reasons, it kicks off all vCPUs and makes them wait until the
new reason has been updated and can be seen by all vCPUs.

There was one WARN() to make sure VM's APICv state is consistent with
vCPU's APICv state in the svm_vcpu_run().  Commit ee49a8932971 ("KVM:
x86: Move SVM's APICv sanity check to common x86") moved that WARN() to
x86 common code vcpu_enter_guest() due to the logic is not unique to
SVM, and added comments to both __kvm_set_or_clear_apicv_inhibit() and
vcpu_enter_guest() to explain this.

However, although the comment in __kvm_set_or_clear_apicv_inhibit()
mentioned the WARN(), it seems forgot to reflect that the WARN() had
been moved to x86 common, i.e., it still mentioned the svm_vcpu_run()
but not vcpu_enter_guest().  Fix it.

Note after the change the first line that contains vcpu_enter_guest()
exceeds 80 characters, but leave it as is to make the diff clean.

Fixes: ee49a8932971 ("KVM: x86: Move SVM's APICv sanity check to common x86")
Signed-off-by: Kai Huang <kai.huang@...el.com>
---
 arch/x86/kvm/x86.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index afd70c274692..7b347e564d10 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10606,11 +10606,11 @@ void __kvm_set_or_clear_apicv_inhibit(struct kvm *kvm,
 	if (!!old != !!new) {
 		/*
 		 * Kick all vCPUs before setting apicv_inhibit_reasons to avoid
-		 * false positives in the sanity check WARN in svm_vcpu_run().
+		 * false positives in the sanity check WARN in vcpu_enter_guest().
 		 * This task will wait for all vCPUs to ack the kick IRQ before
 		 * updating apicv_inhibit_reasons, and all other vCPUs will
 		 * block on acquiring apicv_update_lock so that vCPUs can't
-		 * redo svm_vcpu_run() without seeing the new inhibit state.
+		 * redo vcpu_enter_guest() without seeing the new inhibit state.
 		 *
 		 * Note, holding apicv_update_lock and taking it in the read
 		 * side (handling the request) also prevents other vCPUs from
-- 
2.46.0