Re: [PATCH 1/3] qemu_monitor: introduce new function to get QOM path

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




On 12/11/2014 10:42 AM, Pavel Hrdina wrote:
> 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@xxxxxxxxxx>
> ---
>  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;
> +}
> +
> +

NIT: You added a /** as the comment opener previously, but not here.

> +/* 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) {

A bit of a bikeshed, but the "/" could be moved into the called function
- I say this only because in patch 3 you call qemuMonitorFindObjectPath
with "/".

Could probably also just pass 'mon' and deref 'mon->vm' in the called
routine.

ACK,

John

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

--
libvir-list mailing list
libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list




[Index of Archives]     [Virt Tools]     [Libvirt Users]     [Lib OS Info]     [Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Big List of Linux Books]     [Yosemite News]     [KDE Users]     [Fedora Tools]