Hi, all: The patchset (https://lkml.org/lkml/2014/3/18/309) fixed migration of Windows guests, but commit 0bc830b05c667218d703f2026ec866c49df974fc (KVM: ioapic: clear IRR for edge-triggered interrupts at delivery) introduced a bug (see https://www.mail-archive.com/kvm@xxxxxxxxxxxxxxx/msg109813.html). >From the description "Unlike the old qemu-kvm, which really never did that, with new QEMU it is for some reason somewhat likely to migrate a VM with a nonzero IRR in the ioapic." Why could new QEMU do that? I can not find any codes about the "some reason".. As we know, once a irq is set in kvm's ioapic, the ioapic will send that irq to lapic, this is an "atomic" operation. Then, kvm will inject them in inject_pending_event(or set rvi in apic-v case). QEMU will also save the pending irq when doing migration. I can not find a point which guest could lose a irq, but this scenario really exists. Any ideas? Thanks, Wincy -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
