Re: [libvirt] PATCH: Support initial boot time CPU affinity mask

The XML format allows for an initial CPU mask to be specified for a guests vCPUs. eg with this XML: <vcpu cpuset='1-4,8-20,525'>1</vcpu>

Since we have CPU pinning support from my previous patch, adding in the initial pinning is fairly easy. We first pass the '-S' arg to QEMU when forking it. This causes it to initialize, but not start the CPUs in the guest. We then set the affinity mask for all its CPUs, and then send the 'cont' command to the monitor to start execution.

+ /* Extract domain vcpu info */ + obj = xmlXPathEval(BAD_CAST "string(/domain/vcpu[1]/@cpuset)", ctxt); + if ((obj == NULL) || (obj->type != XPATH_STRING) || + (obj->stringval == NULL) || (obj->stringval[0] == 0)) { + /* Allow use on all CPUS */ + memset(def->cpumask, 1, QEMUD_CPUMASK_LEN); + } else { + char *set = (char *)obj->stringval; + memset(def->cpumask, 0, QEMUD_CPUMASK_LEN); + if (virParseCpuSet(conn, (const char **)&set, + 0, def->cpumask, + QEMUD_CPUMASK_LEN) < 0) { + qemudReportError(conn, NULL, NULL, VIR_ERR_INTERNAL_ERROR, + "%s", _("malformed vcpu mask information")); + goto error; + } + } + xmlXPathFreeObject(obj);

virBufferVSprintf(&buf, " <memory>%lu</memory>\n", def->maxmem); virBufferVSprintf(&buf, " <currentMemory>%lu</currentMemory>\n", def->memory); - virBufferVSprintf(&buf, " <vcpu>%d</vcpu>\n", def->vcpus); + + for (n = 0 ; n < QEMUD_CPUMASK_LEN ; n++) + if (def->cpumask[n] != 1) + allones = 0; + + if (allones) { + virBufferVSprintf(&buf, " <vcpu>%d</vcpu>\n", def->vcpus);