[libvirt] [PATCH 2/6] qemu: use query-cpus-fast in JSON monitor

[Viktor Mihajlovski]

Use query-cpus-fast instead of query-cpus if supported by QEMU.
Based on the QEMU_CAPS_QUERY_CPUS_FAST capability.

Signed-off-by: Viktor Mihajlovski <mihajlov at linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy at linux.vnet.ibm.com>
---
 src/qemu/qemu_monitor.c      | 10 ++++++++--
 src/qemu/qemu_monitor_json.c | 26 +++++++++++++++++---------
 src/qemu/qemu_monitor_json.h |  3 ++-
 tests/qemumonitorjsontest.c  |  2 +-
 4 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index ad5c572..dad1383 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -2012,6 +2012,7 @@ qemuMonitorGetCPUInfo(qemuMonitorPtr mon,
     int ret = -1;
     int rc;
     qemuMonitorCPUInfoPtr info = NULL;
+    bool fast;
 
     QEMU_CHECK_MONITOR(mon);
 
@@ -2028,8 +2029,12 @@ qemuMonitorGetCPUInfo(qemuMonitorPtr mon,
         (qemuMonitorJSONGetHotpluggableCPUs(mon, &hotplugcpus, &nhotplugcpus)) < 0)
         goto cleanup;
 
+    fast = virQEMUCapsGet(QEMU_DOMAIN_PRIVATE(mon->vm)->qemuCaps,
+                          QEMU_CAPS_QUERY_CPUS_FAST);
+
     if (mon->json)
-        rc = qemuMonitorJSONQueryCPUs(mon, &cpuentries, &ncpuentries, hotplug);
+        rc = qemuMonitorJSONQueryCPUs(mon, &cpuentries, &ncpuentries, hotplug,
+                                      fast);
     else
         rc = qemuMonitorTextQueryCPUs(mon, &cpuentries, &ncpuentries);
 
@@ -2082,7 +2087,8 @@ qemuMonitorGetCpuHalted(qemuMonitorPtr mon,
     QEMU_CHECK_MONITOR_NULL(mon);
 
     if (mon->json)
-        rc = qemuMonitorJSONQueryCPUs(mon, &cpuentries, &ncpuentries, false);
+        rc = qemuMonitorJSONQueryCPUs(mon, &cpuentries, &ncpuentries, false,
+                                      false);
     else
         rc = qemuMonitorTextQueryCPUs(mon, &cpuentries, &ncpuentries);
 
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index a09e93e..2ecdf0a 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -1466,7 +1466,8 @@ int qemuMonitorJSONSystemReset(qemuMonitorPtr mon)
 static int
 qemuMonitorJSONExtractCPUInfo(virJSONValuePtr data,
                               struct qemuMonitorQueryCpusEntry **entries,
-                              size_t *nentries)
+                              size_t *nentries,
+                              bool fast)
 {
     struct qemuMonitorQueryCpusEntry *cpus = NULL;
     int ret = -1;
@@ -1491,11 +1492,13 @@ qemuMonitorJSONExtractCPUInfo(virJSONValuePtr data,
         }
 
         /* Some older qemu versions don't report the thread_id so treat this as
-         * non-fatal, simply returning no data */
-        ignore_value(virJSONValueObjectGetNumberInt(entry, "CPU", &cpuid));
-        ignore_value(virJSONValueObjectGetNumberInt(entry, "thread_id", &thread));
+         * non-fatal, simply returning no data.
+         * The return data of query-cpus-fast has different field names
+         */
+        ignore_value(virJSONValueObjectGetNumberInt(entry, fast ? "cpu-index" : "CPU", &cpuid));
+        ignore_value(virJSONValueObjectGetNumberInt(entry, fast ? "thread-id" : "thread_id", &thread));
         ignore_value(virJSONValueObjectGetBoolean(entry, "halted", &halted));
-        qom_path = virJSONValueObjectGetString(entry, "qom_path");
+        qom_path = virJSONValueObjectGetString(entry, fast ? "qom-path" : "qom_path");
 
         cpus[i].qemu_id = cpuid;
         cpus[i].tid = thread;
@@ -1520,10 +1523,12 @@ qemuMonitorJSONExtractCPUInfo(virJSONValuePtr data,
  * @mon: monitor object
  * @entries: filled with detected entries on success
  * @nentries: number of entries returned
+ * @force: force exit on error
+ * @fast: use query-cpus-fast
  *
  * Queries qemu for cpu-related information. Failure to execute the command or
  * extract results does not produce an error as libvirt can continue without
- * this information.
+ * this information, unless the caller has specified @force == true.
  *
  * Returns 0 on success, -1 on a fatal error (oom ...) and -2 if the
  * query failed gracefully.
@@ -1532,10 +1537,13 @@ int
 qemuMonitorJSONQueryCPUs(qemuMonitorPtr mon,
                          struct qemuMonitorQueryCpusEntry **entries,
                          size_t *nentries,
-                         bool force)
+                         bool force,
+                         bool fast)
 {
     int ret = -1;
-    virJSONValuePtr cmd = qemuMonitorJSONMakeCommand("query-cpus", NULL);
+    virJSONValuePtr cmd =
+        qemuMonitorJSONMakeCommand(fast ? "query-cpus-fast" : "query-cpus",
+                                   NULL);
     virJSONValuePtr reply = NULL;
     virJSONValuePtr data;
 
@@ -1553,7 +1561,7 @@ qemuMonitorJSONQueryCPUs(qemuMonitorPtr mon,
         goto cleanup;
     }
 
-    ret = qemuMonitorJSONExtractCPUInfo(data, entries, nentries);
+    ret = qemuMonitorJSONExtractCPUInfo(data, entries, nentries, fast);
 
  cleanup:
     virJSONValueFree(cmd);
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index ec243be..e03299a 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -60,7 +60,8 @@ int qemuMonitorJSONSystemReset(qemuMonitorPtr mon);
 int qemuMonitorJSONQueryCPUs(qemuMonitorPtr mon,
                              struct qemuMonitorQueryCpusEntry **entries,
                              size_t *nentries,
-                             bool force);
+                             bool force,
+                             bool fast);
 int qemuMonitorJSONGetVirtType(qemuMonitorPtr mon,
                                virDomainVirtType *virtType);
 int qemuMonitorJSONUpdateVideoMemorySize(qemuMonitorPtr mon,
diff --git a/tests/qemumonitorjsontest.c b/tests/qemumonitorjsontest.c
index 908ec3a..6824623 100644
--- a/tests/qemumonitorjsontest.c
+++ b/tests/qemumonitorjsontest.c
@@ -1420,7 +1420,7 @@ testQemuMonitorJSONqemuMonitorJSONQueryCPUs(const void *data)
         goto cleanup;
 
     if (qemuMonitorJSONQueryCPUs(qemuMonitorTestGetMonitor(test),
-                                 &cpudata, &ncpudata, true) < 0)
+                                 &cpudata, &ncpudata, true, false) < 0)
         goto cleanup;
 
     if (ncpudata != 4) {
-- 
1.9.1