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* [PATCH] KVM: x86: Remove outdated comments and code in kvm_on_user_return()
@ 2025-09-12  7:35 Hou Wenlong
  2025-09-12  8:35 ` Chao Gao
  0 siblings, 1 reply; 7+ messages in thread
From: Hou Wenlong @ 2025-09-12  7:35 UTC (permalink / raw)
  To: kvm
  Cc: Sean Christopherson, Paolo Bonzini, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, Dave Hansen, x86, H. Peter Anvin, linux-kernel

The commit a377ac1cd9d7b ("x86/entry: Move user return notifier out of
loop") moved fire_user_return_notifiers() into the section with
interrupts disabled, so the callback kvm_on_user_return() cannot be
interrupted by kvm_arch_disable_virtualization_cpu() now. Therefore,
remove the outdated comments and local_irq_save()/local_irq_restore()
code in kvm_on_user_return().

Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
---
 arch/x86/kvm/x86.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 33fba801b205..10afbacb1851 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -568,18 +568,12 @@ static void kvm_on_user_return(struct user_return_notifier *urn)
 	struct kvm_user_return_msrs *msrs
 		= container_of(urn, struct kvm_user_return_msrs, urn);
 	struct kvm_user_return_msr_values *values;
-	unsigned long flags;

-	/*
-	 * Disabling irqs at this point since the following code could be
-	 * interrupted and executed through kvm_arch_disable_virtualization_cpu()
-	 */
-	local_irq_save(flags);
-	if (msrs->registered) {
-		msrs->registered = false;
-		user_return_notifier_unregister(urn);
-	}
-	local_irq_restore(flags);
+	lockdep_assert_irqs_disabled();
+
+	msrs->registered = false;
+	user_return_notifier_unregister(urn);
+
 	for (slot = 0; slot < kvm_nr_uret_msrs; ++slot) {
 		values = &msrs->values[slot];
 		if (values->host != values->curr) {
--
2.31.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2025-09-16  0:13 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-12  7:35 [PATCH] KVM: x86: Remove outdated comments and code in kvm_on_user_return() Hou Wenlong
2025-09-12  8:35 ` Chao Gao
2025-09-12  9:38   ` Hou Wenlong
2025-09-12 14:11     ` Hou Wenlong
2025-09-12 14:40       ` Sean Christopherson
2025-09-13  5:06         ` Hou Wenlong
2025-09-16  0:13           ` Sean Christopherson

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