Re: [libvirt] [PATCH v3 05/20] Remove probing of CPU models when launching QEMU guests

From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; When launching a QEMU guest the binary is probed to discover the list of supported CPU names. Remove this probing with a simple lookup of CPU models in the qemuCapsPtr object. This avoids another invocation of the QEMU binary during the startup path. As a nice benefit we can now remove all the nasty hacks from the test suite which were done to avoid having to exec QEMU on the test system. The building of the -cpu command line can just rely on data we pre-populate in qemuCapsPtr.

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index dd043a1..c73034d 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -4067,7 +4067,7 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver, virCPUDefPtr guest = NULL; virCPUDefPtr cpu = NULL; size_t ncpus = 0; - const char **cpus = NULL; + char **cpus = NULL; const char *default_model; union cpuData *data = NULL; bool have_cpu = false; @@ -4089,12 +4089,8 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver, const char *preferred; int hasSVM; - if (host && - qemuCapsProbeCPUModels(emulator, caps, host->arch, - &ncpus, &cpus) < 0) - goto cleanup; - - if (!ncpus || !host) { + if (!host || + (ncpus = qemuCapsGetCPUDefinitions(caps, &cpus)) == 0) { virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", _("CPU specification not supported by hypervisor")); goto cleanup; @@ -4163,7 +4159,7 @@ qemuBuildCpuArgStr(const struct qemud_driver *driver, guest->type = VIR_CPU_TYPE_GUEST; guest->fallback = cpu->fallback; - if (cpuDecode(guest, data, cpus, ncpus, preferred) < 0) + if (cpuDecode(guest, data, (const char **)cpus, ncpus, preferred) < 0)

goto cleanup; virBufferAdd(&buf, guest->model, -1);