From d3a5d3a03e6dd4230c44656f130acbf1f9821be5 Mon Sep 17 00:00:00 2001

Message-Id: <d3a5d3a03e6dd4230c44656f130acbf1f9821be5@dist-git>

From: Pavel Hrdina <phrdina@redhat.com>

Date: Wed, 14 Jan 2015 13:38:26 +0100

Subject: [PATCH] qemu_monitor: introduce new function to get QOM path

The search is done recursively only through QOM object that has a type

prefixed with "child<" as this indicate that the QOM is a parent for

other QOM objects.

The usage is that you give known device name with starting path where to

search.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

(cherry picked from commit cc41c64878590d7016e0dfa488d345e8634c3bf2)

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1180574

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

---

 src/qemu/qemu_monitor.c | 178 ++++++++++++++++++++++++++++--------------------

 1 file changed, 105 insertions(+), 73 deletions(-)

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

index f797f4f..df7bb45 100644

--- a/src/qemu/qemu_monitor.c

+++ b/src/qemu/qemu_monitor.c

@@ -1012,38 +1012,106 @@ qemuMonitorSetOptions(qemuMonitorPtr mon, virJSONValuePtr options)

     mon->options = options;

 }

-/* Search the qom objects for the balloon driver object by it's known name

- * of "virtio-balloon-pci".  The entry for the driver will be found in the

- * returned 'type' field using the syntax "child<virtio-balloon-pci>".

- *

- * Once found, check the entry to ensure it has the correct property listed.

- * If it does not, then obtaining statistics from qemu will not be possible.

- * This feature was added to qemu 1.5.

+

+/**

+ * Search the qom objects by it's known name.  The name is compared against

+ * filed 'type' formatted as 'link<%name>'.

  *

  * This procedure will be call recursively until found or the qom-list is

  * exhausted.

  *

  * Returns:

  *

- *   1  - Found

- *   0  - Not found still looking

+ *   0  - Found

  *  -1  - Error bail out

+ *  -2  - Not found

  *

  * NOTE: This assumes we have already called qemuDomainObjEnterMonitor()

  */

 static int

-qemuMonitorFindBalloonObjectPath(qemuMonitorPtr mon,

-                                 virDomainObjPtr vm,

-                                 const char *curpath)

+qemuMonitorFindObjectPath(qemuMonitorPtr mon,

+                          const char *curpath,

+                          const char *name,

+                          char **path)

 {

-    ssize_t i, j, npaths = 0, nprops = 0;

-    int ret = 0;

+    ssize_t i, npaths = 0;

+    int ret = -2;

     char *nextpath = NULL;

+    char *type = NULL;

     qemuMonitorJSONListPathPtr *paths = NULL;

+

+    if (virAsprintf(&type, "link<%s>", name) < 0)

+        return -1;

+

+    VIR_DEBUG("Searching for '%s' Object Path starting at '%s'", type, curpath);

+

+    npaths = qemuMonitorJSONGetObjectListPaths(mon, curpath, &paths);

+    if (npaths < 0)

+        goto cleanup;

+

+    for (i = 0; i < npaths && ret == -2; i++) {

+

+        if (STREQ_NULLABLE(paths[i]->type, type)) {

+            VIR_DEBUG("Path to '%s' is '%s/%s'", type, curpath, paths[i]->name);

+            ret = 0;

+            if (virAsprintf(path, "%s/%s", curpath, paths[i]->name) < 0) {

+                *path = NULL;

+                ret = -1;

+            }

+            goto cleanup;

+        }

+

+        /* Type entries that begin with "child<" are a branch that can be

+         * traversed looking for more entries

+         */

+        if (paths[i]->type && STRPREFIX(paths[i]->type, "child<")) {

+            if (virAsprintf(&nextpath, "%s/%s", curpath, paths[i]->name) < 0) {

+                ret = -1;

+                goto cleanup;

+            }

+

+            ret = qemuMonitorFindObjectPath(mon, nextpath, name, path);

+        }

+    }

+

+ cleanup:

+    for (i = 0; i < npaths; i++)

+        qemuMonitorJSONListPathFree(paths[i]);

+    VIR_FREE(paths);

+    VIR_FREE(nextpath);

+    VIR_FREE(type);

+    return ret;

+}

+

+

+/**

+ * Search the qom objects for the balloon driver object by it's known name

+ * of "virtio-balloon-pci".  The entry for the driver will be found by using

+ * function "qemuMonitorFindObjectPath".

+ *

+ * Once found, check the entry to ensure it has the correct property listed.

+ * If it does not, then obtaining statistics from QEMU will not be possible.

+ * This feature was added to QEMU 1.5.

+ *

+ * Returns:

+ *

+ *   0  - Found

+ *  -1  - Not found or error

+ *

+ * NOTE: This assumes we have already called qemuDomainObjEnterMonitor()

+ */

+static int

+qemuMonitorFindBalloonObjectPath(qemuMonitorPtr mon,

+                                 const char *curpath)

+{

+    ssize_t i, nprops = 0;

+    int ret = -1;

+    char *path = NULL;

     qemuMonitorJSONListPathPtr *bprops = NULL;

+    virDomainObjPtr vm = mon->vm;

     if (mon->balloonpath) {

-        return 1;

+        return 0;

     } else if (mon->ballooninit) {

         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

                        _("Cannot determine balloon device path"));

@@ -1059,70 +1127,34 @@ qemuMonitorFindBalloonObjectPath(qemuMonitorPtr mon,

         return -1;

     }

-    VIR_DEBUG("Searching for Balloon Object Path starting at %s", curpath);

-

-    npaths = qemuMonitorJSONGetObjectListPaths(mon, curpath, &paths);

-    if (npaths < 0)

+    if (qemuMonitorFindObjectPath(mon, curpath, "virtio-balloon-pci", &path) < 0)

         return -1;

-    for (i = 0; i < npaths && ret == 0; i++) {

-

-        if (STREQ_NULLABLE(paths[i]->type, "link<virtio-balloon-pci>")) {

-            VIR_DEBUG("Path to <virtio-balloon-pci> is '%s/%s'",

-                      curpath, paths[i]->name);

-            if (virAsprintf(&nextpath, "%s/%s", curpath, paths[i]->name) < 0) {

-                ret = -1;

-                goto cleanup;

-            }

-

-            /* Now look at the each of the property entries to determine

-             * whether "guest-stats-polling-interval" exists.  If not,

-             * then this version of qemu/kvm does not support the feature.

-             */

-            nprops = qemuMonitorJSONGetObjectListPaths(mon, nextpath, &bprops);

-            if (nprops < 0) {

-                ret = -1;

-                goto cleanup;

-            }

-

-            for (j = 0; j < nprops; j++) {

-                if (STREQ(bprops[j]->name, "guest-stats-polling-interval")) {

-                    VIR_DEBUG("Found Balloon Object Path %s", nextpath);

-                    mon->balloonpath = nextpath;

-                    nextpath = NULL;

-                    ret = 1;

-                    goto cleanup;

-                }

-            }

-

-            /* If we get here, we found the path, but not the property */

-            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

-                           _("Property 'guest-stats-polling-interval' "

-                             "not found on memory balloon driver."));

-            ret = -1;

+    nprops = qemuMonitorJSONGetObjectListPaths(mon, path, &bprops);

+    if (nprops < 0)

+        goto cleanup;

+

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

+        if (STREQ(bprops[i]->name, "guest-stats-polling-interval")) {

+            VIR_DEBUG("Found Balloon Object Path %s", path);

+            mon->balloonpath = path;

+            path = NULL;

+            ret = 0;

             goto cleanup;

         }

-

-        /* Type entries that begin with "child<" are a branch that can be

-         * traversed looking for more entries

-         */

-        if (paths[i]->type && STRPREFIX(paths[i]->type, "child<")) {

-            if (virAsprintf(&nextpath, "%s/%s", curpath, paths[i]->name) < 0) {

-                ret = -1;

-                goto cleanup;

-            }

-            ret = qemuMonitorFindBalloonObjectPath(mon, vm, nextpath);

-        }

     }

+

+    /* If we get here, we found the path, but not the property */

+    virReportError(VIR_ERR_INTERNAL_ERROR, "%s",

+                   _("Property 'guest-stats-polling-interval' "

+                     "not found on memory balloon driver."));

+

  cleanup:

-    for (i = 0; i < npaths; i++)

-        qemuMonitorJSONListPathFree(paths[i]);

-    VIR_FREE(paths);

-    for (j = 0; j < nprops; j++)

-        qemuMonitorJSONListPathFree(bprops[j]);

+    for (i = 0; i < nprops; i++)

+        qemuMonitorJSONListPathFree(bprops[i]);

     VIR_FREE(bprops);

-    VIR_FREE(nextpath);

+    VIR_FREE(path);

     return ret;

 }

@@ -1636,7 +1668,7 @@ int qemuMonitorGetMemoryStats(qemuMonitorPtr mon,

     }

     if (mon->json) {

-        ignore_value(qemuMonitorFindBalloonObjectPath(mon, mon->vm, "/"));

+        ignore_value(qemuMonitorFindBalloonObjectPath(mon, "/"));

         mon->ballooninit = true;

         ret = qemuMonitorJSONGetMemoryStats(mon, mon->balloonpath,

                                             stats, nr_stats);

@@ -1664,7 +1696,7 @@ int qemuMonitorSetMemoryStatsPeriod(qemuMonitorPtr mon,

         return -1;

     }

-    if (qemuMonitorFindBalloonObjectPath(mon, mon->vm, "/") == 1) {

+    if (qemuMonitorFindBalloonObjectPath(mon, "/") == 0) {

         ret = qemuMonitorJSONSetMemoryStatsPeriod(mon, mon->balloonpath,

                                                   period);

     }

-- 

2.2.1