Re: [libvirt] [PATCH 4/6] Canonicalize qemu machine types

In qemu-0.11 there is a 'pc-0.10' machine type which allows you to run guests with a machine which is compatible with the pc machine in qemu-0.10 - e.g. using the original PCI class for virtio-blk and virtio-console and disabling MSI support in virtio-net. The idea here is that we don't want to suprise guests by changing the hardware when qemu is updated. I've just posted some patches for qemu-0.11 which allows libvirt to canonicalize the 'pc' machine alias to the latest machine version. This patches makes us use that so that when a guest is configured to use the 'pc' machine type, we resolve that to 'pc-0.11' machine and save that in the guest XML. See also: https://fedoraproject.org/wiki/Features/KVM_Stable_Guest_ABI * src/qemu_conf.c: add qemudCanonicalizeMachine() to canonicalize the machine type according to the machine aliases in capabilities

/* Format is: - * <machine> <desc> [(default)] + * <machine> <desc> [(default)|(alias of <canonical>)] */ static int qemudParseMachineTypesStr(const char *output, @@ -319,6 +319,15 @@ qemudParseMachineTypesStr(const char *output, list[0] = machine; nitems++; } + + if ((t = strstr(p, "(alias of ")) && (!next || t < next)) { + p = t + strlen("(alias of "); + if (!(t = strchr(p, ')')) || (next && t >= next)) + continue; + + if (!(machine->canonical = strndup(p, t - p))) + goto error; + } } while ((p = next));

+static int +qemudCanonicalizeMachineFromInfo(virDomainDefPtr def, + virCapsGuestDomainInfoPtr info, + char **canonical) +{ + int i; + + *canonical = NULL; + + for (i = 0; i < info->nmachines; i++) { + virCapsGuestMachinePtr machine = info->machines[i]; + + if (!machine->canonical) + continue; + + if (strcmp(def->os.machine, machine->name) != 0) + continue; + + if (!(*canonical = strdup(machine->canonical)))

+ return -1; + + break;