Michael, I'm about to post a nice simple v5 of this, but there are a couple of your comments I am NOT addressing: >> >> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c >> index b72b34e..3c9da23 100644 >> --- a/hw/acpi/piix4.c >> +++ b/hw/acpi/piix4.c >> @@ -200,12 +200,26 @@ static const VMStateDescription vmstate_pci_status = { >> } >> }; >> >> +static const VMStateDescription vmstate_acpi_compat; >> + > > don't forward declare things, put them right here. This is not addressable in v5; in v5 this is a forward declaration of vmstate_acpi (not _compat). vmstate_acpi references acpi_load_old, and acpi_load_old references vmstate_acpi, so we need a forward reference for one of them in any case. >> + qemu_opt_get_bool(qemu_get_machine_opts(), "qemu-kvm-migration", >> + DEFAULT_QEMU_KVM_MIGRATION)) { >> + return vmstate_load_state(f, &vmstate_acpi_compat, >> + opaque, version_id); >> + } > > else if version_id == 2 return -EINVAL? This is incorrect I think. A version_id of 2 with qemu-kvm_migration off is permissible, and indicates an inbound migration from qemu-git 1.2, i.e. the old manual loading should be run. >> /* qemu-kvm 1.2 uses version 3 but advertised as 2 >> - * To support incoming qemu-kvm 1.2 migration, change version_id >> - * and minimum_version_id to 2 below (which breaks migration from >> + * To support incoming qemu-kvm 1.2 migration, we support >> + * via a command line option a change to minimum_version_id >> + * of 2 in a _compat structure (which breaks migration from >> * qemu 1.2). > > Actually it's version 3 that breaks migration right? > Pls say this explicitly: s/which/version 3 breaks migration from qemu 1.2/ It's changing the minimum version ID to 2 (from 3) which would break migration from qemu (git) 1.2, because that uses a version ID of 2, and we want the old loader to run in that case. I've made this clearer. -- Alex Bligh -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list