Re: [libvirt] [PATCH 1/3] 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(a)redhat.com&gt; --- src/qemu/qemu_monitor.c | 173 ++++++++++++++++++++++++++++-------------------- 1 file changed, 102 insertions(+), 71 deletions(-) diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c index c9c84f9..ee4460f 100644 --- a/src/qemu/qemu_monitor.c +++ b/src/qemu/qemu_monitor.c @@ -1008,22 +1008,90 @@ 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 +qemuMonitorFindObjectPath(qemuMonitorPtr mon, + const char *curpath, + const char *name, + char **path) +{ + 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() */ @@ -1032,14 +1100,13 @@ qemuMonitorFindBalloonObjectPath(qemuMonitorPtr mon, virDomainObjPtr vm, const char *curpath) { - ssize_t i, j, npaths = 0, nprops = 0; - int ret = 0; - char *nextpath = NULL; - qemuMonitorJSONListPathPtr *paths = NULL; + ssize_t i, nprops = 0; + int ret = -1; + char *path = NULL; qemuMonitorJSONListPathPtr *bprops = NULL; if (mon->balloonpath) { - return 1; + return 0; } else if (mon->ballooninit) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("Cannot determine balloon device path")); @@ -1055,70 +1122,34 @@ 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; } @@ -1660,7 +1691,7 @@ int qemuMonitorSetMemoryStatsPeriod(qemuMonitorPtr mon, return -1; } - if (qemuMonitorFindBalloonObjectPath(mon, mon->vm, "/") == 1) { + if (qemuMonitorFindBalloonObjectPath(mon, mon->vm, "/") == 0) {

ret = qemuMonitorJSONSetMemoryStatsPeriod(mon, mon->balloonpath, period); }