kvm: x86: correctly reset dest_map->vector when restoring LAPIC state (b0eaf450) · Commits · 戴 / test

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: Fixes: Cc: stable@vger.kernel.org Cc: Joerg Roedel <jroedel@suse.de> Cc: David Gilbert <dgilbert@redhat.com> Reviewed-by:

Radim Krčmář <rkrcmar@redhat.com> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/ioapic.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -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);
		}

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