From: Sean Christopherson Date: Thu, 18 Jun 2026 17:45:27 +0000 (-0700) Subject: KVM: x86: WARN (once) if RTC pending EOI tracking goes off the rails X-Git-Tag: v7.2-rc1~30^2~5 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=cc3d0e1afd1077796df72da85e0da5266fd532f2;p=thirdparty%2Flinux.git KVM: x86: WARN (once) if RTC pending EOI tracking goes off the rails WARN once if KVM's tracking for pending EOIs for Real-Time Clock IRQs goes off the rails, as there's no reason to bug the host or risk a DoS due to spamming dmesg with endless WARNs. Absolute worst case scenario, guest time will go awry. Signed-off-by: Sean Christopherson Reviewed-by: Kai Huang Message-ID: <20260618174527.1982333-1-seanjc@google.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index 88bd226f3b73b..757667fb2bfa0 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -84,7 +84,7 @@ static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic); static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic) { - if (WARN_ON(ioapic->rtc_status.pending_eoi < 0)) + if (WARN_ON_ONCE(ioapic->rtc_status.pending_eoi < 0)) kvm_rtc_eoi_tracking_restore_all(ioapic); } @@ -484,7 +484,7 @@ static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status) * ensures that it is only called if it is >= zero, namely * if rtc_irq_check_coalesced returns false). */ - BUG_ON(ioapic->rtc_status.pending_eoi != 0); + WARN_ON_ONCE(ioapic->rtc_status.pending_eoi); ret = __kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, &ioapic->rtc_status); ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);