From 93976c766d7714f0b17b1ebc274f1ef04a2885d7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 14 Sep 2016 23:39:12 +0200 Subject: [PATCH] kvm: x86: correctly reset dest_map->vector when restoring LAPIC state MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When userspace sends KVM_SET_LAPIC, KVM schedules a check between the vCPU's IRR and ISR and the IOAPIC redirection table, in order to re-establish the IOAPIC's dest_map (the list of CPUs servicing the real-time clock interrupt with the corresponding vectors). However, __rtc_irq_eoi_tracking_restore_one was forgetting to set dest_map->vectors. Because of this, the IOAPIC did not process the real-time clock interrupt EOI, ioapic->rtc_status.pending_eoi got stuck at a non-zero value, and further RTC interrupts were reported to userspace as coalesced. Fixes: 7373ddff22799af6290597fa50e477167f8b5ada Fixes: 55525399f4afbe121585a27acba877a93b882ffe Cc: stable@vger.kernel.org Cc: Joerg Roedel Cc: David Gilbert Reviewed-by: Radim Krčmář Signed-off-by: Paolo Bonzini --- arch/x86/kvm/ioapic.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c index 5f42d038fcb4c..c7220ba94aa77 100644 --- a/arch/x86/kvm/ioapic.c +++ b/arch/x86/kvm/ioapic.c @@ -109,6 +109,7 @@ static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu) { bool new_val, old_val; struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic; + struct dest_map *dest_map = &ioapic->rtc_status.dest_map; union kvm_ioapic_redirect_entry *e; e = &ioapic->redirtbl[RTC_GSI]; @@ -117,16 +118,17 @@ static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu) return; new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector); - old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map.map); + old_val = test_bit(vcpu->vcpu_id, dest_map->map); if (new_val == old_val) return; if (new_val) { - __set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map.map); + __set_bit(vcpu->vcpu_id, dest_map->map); + dest_map->vectors[vcpu->vcpu_id] = e->fields.vector; ioapic->rtc_status.pending_eoi++; } else { - __clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map.map); + __clear_bit(vcpu->vcpu_id, dest_map->map); ioapic->rtc_status.pending_eoi--; rtc_status_pending_eoi_check_valid(ioapic); } -- 2.39.5