qemu: Implement bulk stats API and one of the stats groups to return

Implement the API function for virDomainListGetStats and
virConnectGetAllDomainStats in a modular way and implement the
VIR_DOMAIN_STATS_STATE group of statistics.

Although it may look like the function looks universal I'd rather not
expose it to other drivers as the coming stats groups are likely to do
qemu specific stuff to obtain the stats.

src/qemu/qemu_driver.c

@@ -17198,6 +17198,202 @@ qemuConnectGetDomainCapabilities(virConnectPtr conn,
 }
 
 
+static int
+qemuDomainGetStatsState(virDomainObjPtr dom,
+                        virDomainStatsRecordPtr record,
+                        int *maxparams,
+                        unsigned int privflags ATTRIBUTE_UNUSED)
+{
+    if (virTypedParamsAddInt(&record->params,
+                             &record->nparams,
+                             maxparams,
+                             "state.state",
+                             dom->state.state) < 0)
+        return -1;
+
+    if (virTypedParamsAddInt(&record->params,
+                             &record->nparams,
+                             maxparams,
+                             "state.reason",
+                             dom->state.reason) < 0)
+        return -1;
+
+    return 0;
+}
+
+
+typedef int
+(*qemuDomainGetStatsFunc)(virDomainObjPtr dom,
+                          virDomainStatsRecordPtr record,
+                          int *maxparams,
+                          unsigned int flags);
+
+struct qemuDomainGetStatsWorker {
+    qemuDomainGetStatsFunc func;
+    unsigned int stats;
+};
+
+static struct qemuDomainGetStatsWorker qemuDomainGetStatsWorkers[] = {
+    { qemuDomainGetStatsState, VIR_DOMAIN_STATS_STATE},
+    { NULL, 0 }
+};
+
+
+static int
+qemuDomainGetStatsCheckSupport(unsigned int *stats,
+                               bool enforce)
+{
+    unsigned int supportedstats = 0;
+    size_t i;
+
+    for (i = 0; qemuDomainGetStatsWorkers[i].func; i++)
+        supportedstats |= qemuDomainGetStatsWorkers[i].stats;
+
+    if (*stats == 0) {
+        *stats = supportedstats;
+        return 0;
+    }
+
+    if (enforce &&
+        *stats & ~supportedstats) {
+        virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED,
+                       _("Stats types bits 0x%x are not supported by this daemon"),
+                       *stats & ~supportedstats);
+        return -1;
+    }
+
+    *stats &= supportedstats;
+    return 0;
+}
+
+
+static int
+qemuDomainGetStats(virConnectPtr conn,
+                   virDomainObjPtr dom,
+                   unsigned int stats,
+                   virDomainStatsRecordPtr *record,
+                   unsigned int flags)
+{
+    int maxparams = 0;
+    virDomainStatsRecordPtr tmp;
+    size_t i;
+    int ret = -1;
+
+    if (VIR_ALLOC(tmp) < 0)
+        goto cleanup;
+
+    for (i = 0; qemuDomainGetStatsWorkers[i].func; i++) {
+        if (stats & qemuDomainGetStatsWorkers[i].stats) {
+            if (qemuDomainGetStatsWorkers[i].func(dom, tmp, &maxparams,
+                                                  flags) < 0)
+                goto cleanup;
+        }
+    }
+
+    if (!(tmp->dom = virGetDomain(conn, dom->def->name, dom->def->uuid)))
+        goto cleanup;
+
+    *record = tmp;
+    tmp = NULL;
+    ret = 0;
+
+ cleanup:
+    if (tmp) {
+        virTypedParamsFree(tmp->params, tmp->nparams);
+        VIR_FREE(tmp);
+    }
+
+    return ret;
+}
+
+
+static int
+qemuConnectGetAllDomainStats(virConnectPtr conn,
+                             virDomainPtr *doms,
+                             unsigned int ndoms,
+                             unsigned int stats,
+                             virDomainStatsRecordPtr **retStats,
+                             unsigned int flags)
+{
+    virQEMUDriverPtr driver = conn->privateData;
+    virDomainPtr *domlist = NULL;
+    virDomainObjPtr dom = NULL;
+    virDomainStatsRecordPtr *tmpstats = NULL;
+    bool enforce = !!(flags & VIR_CONNECT_GET_ALL_DOMAINS_STATS_ENFORCE_STATS);
+    int ntempdoms;
+    int nstats = 0;
+    size_t i;
+    int ret = -1;
+
+    if (ndoms)
+        virCheckFlags(VIR_CONNECT_GET_ALL_DOMAINS_STATS_ENFORCE_STATS, -1);
+    else
+        virCheckFlags(VIR_CONNECT_LIST_DOMAINS_FILTERS_ACTIVE |
+                      VIR_CONNECT_LIST_DOMAINS_FILTERS_PERSISTENT |
+                      VIR_CONNECT_LIST_DOMAINS_FILTERS_STATE |
+                      VIR_CONNECT_GET_ALL_DOMAINS_STATS_ENFORCE_STATS, -1);
+
+    if (virConnectGetAllDomainStatsEnsureACL(conn) < 0)
+        return -1;
+
+    if (qemuDomainGetStatsCheckSupport(&stats, enforce) < 0)
+        return -1;
+
+    if (!ndoms) {
+        unsigned int lflags = flags & (VIR_CONNECT_LIST_DOMAINS_FILTERS_ACTIVE |
+                                       VIR_CONNECT_LIST_DOMAINS_FILTERS_PERSISTENT |
+                                       VIR_CONNECT_LIST_DOMAINS_FILTERS_STATE);
+
+        if ((ntempdoms = virDomainObjListExport(driver->domains,
+                                                conn,
+                                                &domlist,
+                                                virConnectGetAllDomainStatsCheckACL,
+                                                lflags)) < 0)
+            goto cleanup;
+
+        ndoms = ntempdoms;
+        doms = domlist;
+    }
+
+    if (VIR_ALLOC_N(tmpstats, ndoms + 1) < 0)
+        goto cleanup;
+
+    for (i = 0; i < ndoms; i++) {
+        virDomainStatsRecordPtr tmp = NULL;
+
+        if (!(dom = qemuDomObjFromDomain(doms[i])))
+            continue;
+
+        if (!domlist &&
+            !virConnectGetAllDomainStatsCheckACL(conn, dom->def))
+            continue;
+
+        if (qemuDomainGetStats(conn, dom, stats, &tmp, flags) < 0)
+            goto cleanup;
+
+        if (tmp)
+            tmpstats[nstats++] = tmp;
+
+        virObjectUnlock(dom);
+        dom = NULL;
+    }
+
+    *retStats = tmpstats;
+    tmpstats = NULL;
+
+    ret = nstats;
+
+ cleanup:
+    if (dom)
+        virObjectUnlock(dom);
+
+    virDomainStatsRecordListFree(tmpstats);
+    virDomainListFree(domlist);
+
+    return ret;
+}
+
+
 static virDriver qemuDriver = {
     .no = VIR_DRV_QEMU,
     .name = QEMU_DRIVER_NAME,
@@ -17395,6 +17591,7 @@ static virDriver qemuDriver = {
     .domainSetTime = qemuDomainSetTime, /* 1.2.5 */
     .nodeGetFreePages = qemuNodeGetFreePages, /* 1.2.6 */
     .connectGetDomainCapabilities = qemuConnectGetDomainCapabilities, /* 1.2.7 */
+    .connectGetAllDomainStats = qemuConnectGetAllDomainStats, /* 1.2.8 */
 };