From 4da15317e206ea8dede92b8b6e37805473df5a2f Mon Sep 17 00:00:00 2001

Message-Id: <4da15317e206ea8dede92b8b6e37805473df5a2f@dist-git>

From: Peter Krempa <pkrempa@redhat.com>

Date: Wed, 24 Aug 2016 16:11:23 -0400

Subject: [PATCH] qemu: monitor: Add support for calling

 query-hotpluggable-cpus

https://bugzilla.redhat.com/show_bug.cgi?id=1097930

https://bugzilla.redhat.com/show_bug.cgi?id=1224341

Add support for retrieving information regarding hotpluggable cpu units

supported by qemu. Data returned by the command carries information

needed to figure out the granularity of hotplug, the necessary cpu type

name and the topology information.

Note that qemu doesn't specify any particular order of the entries thus

it's necessary sort them by socket_id, core_id and thread_id to the

order libvirt expects.

(cherry picked from commit 1213f0f8a50d9d3b782e3c336e3373c35c652a55)

---

 src/qemu/qemu_monitor.h      |  16 ++++

 src/qemu/qemu_monitor_json.c | 170 +++++++++++++++++++++++++++++++++++++++++++

 src/qemu/qemu_monitor_json.h |   5 ++

 3 files changed, 191 insertions(+)

diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h

index 83396a4..027a7a9 100644

--- a/src/qemu/qemu_monitor.h

+++ b/src/qemu/qemu_monitor.h

@@ -398,6 +398,22 @@ void qemuMonitorQueryCpusFree(struct qemuMonitorQueryCpusEntry *entries,

                               size_t nentries);

+struct qemuMonitorQueryHotpluggableCpusEntry {

+    char *type; /* name of the cpu to use with device_add */

+    unsigned int vcpus; /* count of virtual cpus in the guest this entry adds */

+    char *qom_path; /* full device qom path only present for online cpus */

+    char *alias; /* device alias, may be NULL for non-hotpluggable entities */

+

+    /* topology information -1 if qemu didn't report given parameter */

+    int node_id;

+    int socket_id;

+    int core_id;

+    int thread_id;

+};

+void qemuMonitorQueryHotpluggableCpusFree(struct qemuMonitorQueryHotpluggableCpusEntry *entries,

+                                          size_t nentries);

+

+

 struct _qemuMonitorCPUInfo {

     pid_t tid;

 };

diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c

index a59b195..1871723 100644

--- a/src/qemu/qemu_monitor_json.c

+++ b/src/qemu/qemu_monitor_json.c

@@ -7209,3 +7209,173 @@ qemuMonitorJSONGetRTCTime(qemuMonitorPtr mon,

     virJSONValueFree(reply);

     return ret;

 }

+

+

+void

+qemuMonitorQueryHotpluggableCpusFree(struct qemuMonitorQueryHotpluggableCpusEntry *entries,

+                                     size_t nentries)

+{

+    struct qemuMonitorQueryHotpluggableCpusEntry *entry;

+    size_t i;

+

+    if (!entries)

+        return;

+

+    for (i = 0; i < nentries; i++) {

+        entry = entries + i;

+

+        VIR_FREE(entry->type);

+        VIR_FREE(entry->qom_path);

+        VIR_FREE(entry->alias);

+    }

+

+    VIR_FREE(entries);

+}

+

+

+/**

+ * [{

+ *    "props": {

+ *      "core-id": 0,

+ *      "thread-id": 0,

+ *      "socket-id": 0

+ *    },

+ *    "vcpus-count": 1,

+ *    "qom-path": "/machine/unattached/device[0]",

+ *    "type": "qemu64-x86_64-cpu"

+ *  },

+ *  {...}

+ * ]

+ */

+static int

+qemuMonitorJSONProcessHotpluggableCpusReply(virJSONValuePtr vcpu,

+                                            struct qemuMonitorQueryHotpluggableCpusEntry *entry)

+{

+    virJSONValuePtr props;

+    const char *tmp;

+

+    if (!(tmp = virJSONValueObjectGetString(vcpu, "type"))) {

+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                       _("query-hotpluggable-cpus didn't return device type"));

+        return -1;

+    }

+

+    if (VIR_STRDUP(entry->type, tmp) < 0)

+        return -1;

+

+    if (virJSONValueObjectGetNumberUint(vcpu, "vcpus-count", &entry->vcpus) < 0) {

+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                       _("query-hotpluggable-cpus didn't return vcpus-count"));

+        return -1;

+    }

+

+    if (!(props = virJSONValueObjectGetObject(vcpu, "props"))) {

+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                       _("query-hotpluggable-cpus didn't return device props"));

+        return -1;

+    }

+

+    entry->node_id = -1;

+    entry->socket_id = -1;

+    entry->core_id = -1;

+    entry->thread_id = -1;

+

+    ignore_value(virJSONValueObjectGetNumberInt(props, "node-id", &entry->node_id));

+    ignore_value(virJSONValueObjectGetNumberInt(props, "socket-id", &entry->socket_id));

+    ignore_value(virJSONValueObjectGetNumberInt(props, "core-id", &entry->core_id));

+    ignore_value(virJSONValueObjectGetNumberInt(props, "thread-id", &entry->thread_id));

+

+    if (entry->node_id == -1 && entry->socket_id == -1 &&

+        entry->core_id == -1 && entry->thread_id == -1) {

+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                       _("query-hotpluggable-cpus entry doesn't report "

+                         "topology information"));

+        return -1;

+    }

+

+    /* qom path is not present unless the vCPU is online */

+    if ((tmp = virJSONValueObjectGetString(vcpu, "qom-path"))) {

+        if (VIR_STRDUP(entry->qom_path, tmp) < 0)

+            return -1;

+

+        /* alias is the part after last slash having a "vcpu" prefix */

+        if ((tmp = strrchr(tmp, '/')) && STRPREFIX(tmp + 1, "vcpu")) {

+            if (VIR_STRDUP(entry->alias, tmp + 1) < 0)

+                return -1;

+        }

+    }

+

+    return 0;

+}

+

+

+static int

+qemuMonitorQueryHotpluggableCpusEntrySort(const void *p1,

+                                          const void *p2)

+{

+    const struct qemuMonitorQueryHotpluggableCpusEntry *a = p1;

+    const struct qemuMonitorQueryHotpluggableCpusEntry *b = p2;

+

+    if (a->socket_id != b->socket_id)

+        return a->socket_id - b->socket_id;

+

+    if (a->core_id != b->core_id)

+        return a->core_id - b->core_id;

+

+    return a->thread_id - b->thread_id;

+}

+

+

+int

+qemuMonitorJSONGetHotpluggableCPUs(qemuMonitorPtr mon,

+                                   struct qemuMonitorQueryHotpluggableCpusEntry **entries,

+                                   size_t *nentries)

+{

+    struct qemuMonitorQueryHotpluggableCpusEntry *info = NULL;

+    ssize_t ninfo = 0;

+    int ret = -1;

+    size_t i;

+    virJSONValuePtr data;

+    virJSONValuePtr cmd;

+    virJSONValuePtr reply = NULL;

+    virJSONValuePtr vcpu;

+

+    if (!(cmd = qemuMonitorJSONMakeCommand("query-hotpluggable-cpus", NULL)))

+        return -1;

+

+    if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)

+        goto cleanup;

+

+    if (qemuMonitorJSONCheckError(cmd, reply) < 0)

+        goto cleanup;

+

+    data = virJSONValueObjectGet(reply, "return");

+

+    if ((ninfo = virJSONValueArraySize(data)) < 0) {

+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                       _("query-hotpluggable-cpus reply is not an array"));

+        goto cleanup;

+    }

+

+    if (VIR_ALLOC_N(info, ninfo) < 0)

+        goto cleanup;

+

+    for (i = 0; i < ninfo; i++) {

+        vcpu = virJSONValueArrayGet(data, i);

+

+        if (qemuMonitorJSONProcessHotpluggableCpusReply(vcpu, info + i) < 0)

+            goto cleanup;

+    }

+

+    qsort(info, ninfo, sizeof(*info), qemuMonitorQueryHotpluggableCpusEntrySort);

+

+    VIR_STEAL_PTR(*entries, info);

+    *nentries = ninfo;

+    ret = 0;

+

+ cleanup:

+    qemuMonitorQueryHotpluggableCpusFree(info, ninfo);

+    virJSONValueFree(cmd);

+    virJSONValueFree(reply);

+    return ret;

+}

diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h

index 2a439da..4db6067 100644

--- a/src/qemu/qemu_monitor_json.h

+++ b/src/qemu/qemu_monitor_json.h

@@ -504,4 +504,9 @@ int qemuMonitorJSONMigrateStartPostCopy(qemuMonitorPtr mon)

 int qemuMonitorJSONGetRTCTime(qemuMonitorPtr mon,

                               struct tm *tm)

     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);

+

+int qemuMonitorJSONGetHotpluggableCPUs(qemuMonitorPtr mon,

+                                       struct qemuMonitorQueryHotpluggableCpusEntry **entries,

+                                       size_t *nentries)

+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3);

 #endif /* QEMU_MONITOR_JSON_H */

-- 

2.10.0