Re: [libvirt] [PATCH v3 12/13] Implement CPU selection in QEMU driver

Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com&gt; --- src/qemu/qemu_conf.c | 401 +++++++++++++++++++++++++++++++++++++++++++++--- src/qemu/qemu_conf.h | 7 + src/qemu/qemu_driver.c | 43 ++++-- 3 files changed, 421 insertions(+), 30 deletions(-) diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c + +int +qemudProbeCPUModels(const char *qemu, + const char *arch, + unsigned int *count, + const char ***cpus) +{ + const char *const qemuarg[] = { qemu, "-cpu", "?", NULL }; + const char *const qemuenv[] = { "LC_ALL=C", NULL }; + enum { MAX_MACHINES_OUTPUT_SIZE = 1024*4 }; + char *output = NULL; + int newstdout = -1; + int ret = -1; + pid_t child; + int status; + int len; + qemudParseCPUModels parse; + + if (count) + *count = 0; + if (cpus) + *cpus = NULL; + + if (STREQ(arch, "i686") || STREQ(arch, "x86_64")) + parse = qemudParseX86Models; + else { + VIR_DEBUG(_("don't know how to parse %s CPU models"), arch); + return 0; + } + + if (virExec(NULL, qemuarg, qemuenv, NULL, + &child, -1, &newstdout, NULL, VIR_EXEC_CLEAR_CAPS) < 0) + return -1; + + len = virFileReadLimFD(newstdout, MAX_MACHINES_OUTPUT_SIZE, &output); + if (len < 0) { + virReportSystemError(NULL, errno, "%s", + _("Unable to read QEMU supported CPU models")); + goto cleanup; + } + + if (parse(output, count, cpus) < 0) {

@@ -808,6 +960,49 @@ qemudCapsInitGuest(virCapsPtr caps, return 0; } + +static int +qemudCapsInitCPU(virCapsPtr caps, + const char *arch) +{ + virCPUDefPtr cpu = NULL; + union cpuData *data = NULL; + virNodeInfo nodeinfo; + int ret = -1; + + if (VIR_ALLOC(cpu) < 0 + || !(cpu->arch = strdup(arch))) { + virReportOOMError(NULL); + goto error; + } + + if (nodeGetInfo(NULL, &nodeinfo)) + goto error; + + cpu->type = VIR_CPU_TYPE_HOST; + cpu->sockets = nodeinfo.sockets * nodeinfo.nodes;

+ cpu->cores = nodeinfo.cores; + cpu->threads = nodeinfo.threads; + + if (!(data = cpuNodeData(NULL, arch)) + || cpuDecode(NULL, cpu, data, 0, NULL) < 0) + goto error; + + caps->host.cpu = cpu; + + ret = 0; + +cleanup: + cpuDataFree(NULL, arch, data); + + return ret; + +error: + virCPUDefFree(cpu); + goto cleanup; +} + + virCapsPtr qemudCapsInit(virCapsPtr old_caps) { struct utsname utsname; virCapsPtr caps; @@ -832,8 +1027,17 @@ virCapsPtr qemudCapsInit(virCapsPtr old_caps) { VIR_WARN0("Failed to query host NUMA topology, disabling NUMA capabilities"); } + if (old_caps == NULL || old_caps->host.cpu == NULL) { + if (qemudCapsInitCPU(caps, utsname.machine) < 0) + VIR_WARN0("Failed to get host CPU"); + } + else { + caps->host.cpu = old_caps->host.cpu; + old_caps->host.cpu = NULL; + } + virCapabilitiesAddHostMigrateTransport(caps, - "tcp"); + "Tcp");

/* First the pure HVM guests */ for (i = 0 ; i < ARRAY_CARDINALITY(arch_info_hvm) ; i++) @@ -1563,6 +1767,99 @@ static void qemudBuildCommandLineChrDevStr(virDomainChrDefPtr dev, } } + +static int +qemudBuildCommandLineCPU(virConnectPtr conn, + const struct qemud_driver *driver, + const virDomainDefPtr def, + const char *emulator, + const struct utsname *ut, + char **opt) +{ + const virCPUDefPtr host = driver->caps->host.cpu; + virCPUDefPtr guest = NULL; + unsigned int ncpus; + const char **cpus = NULL; + union cpuData *data = NULL; + int ret = -1; + virBuffer buf = VIR_BUFFER_INITIALIZER; + int i; + + if (qemudProbeCPUModels(emulator, ut->machine, &ncpus, &cpus) < 0) + goto cleanup; + + if (ncpus > 0 && host && def->cpu && def->cpu->model) { + virCPUCompareResult cmp; + + cmp = cpuGuestData(conn, host, def->cpu, &data); + switch (cmp) { + case VIR_CPU_COMPARE_INCOMPATIBLE: + qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR, + "%s", _("guest CPU is not compatible with host CPU")); + /* fall through */ + case VIR_CPU_COMPARE_ERROR: + goto cleanup; + + default: + break; + } + + if (VIR_ALLOC(guest) < 0 || !(guest->arch = strdup(ut->machine))) + goto no_memory; + + if (qemudProbeCPUModels(emulator, ut->machine, &ncpus, &cpus) < 0 + || cpuDecode(conn, guest, data, ncpus, cpus) < 0) + goto cleanup;

+ + virBufferVSprintf(&buf, "%s", guest->model); + for (i = 0; i < guest->nfeatures; i++) + virBufferVSprintf(&buf, ",+%s", guest->features[i].name); + } + else { + /* + * Need to force a 32-bit guest CPU type if + * + * 1. guest OS is i686 + * 2. host OS is x86_64 + * 3. emulator is qemu-kvm or kvm + * + * Or + * + * 1. guest OS is i686 + * 2. emulator is qemu-system-x86_64 + */ + if (STREQ(def->os.arch, "i686") && + ((STREQ(ut->machine, "x86_64") && + strstr(emulator, "kvm")) || + strstr(emulator, "x86_64"))) + virBufferAddLit(&buf, "qemu32"); + }