[libvirt] [PATCH] qemu: Generate agent socket path if missing

[Jiri Denemark]

On Tue, Apr 09, 2013 at 19:05:28 +0200, Michal Privoznik wrote:
> It's not desired to force users imagine path for a socket they
> are not even supposed to connect to. On the other hand, we
> already have a release where the qemu agent socket path is
> exposed to XML, so we cannot silently drop it from there.
> The new path is generated in form:
> 
> $LOCALSTATEDIR/lib/libvirt/qemu/channel/target/$domain.$name
> ---
>  libvirt.spec.in        |  1 +
>  src/Makefile.am        |  1 +
>  src/conf/domain_conf.c | 34 ++++++++++++++++------------------
>  src/qemu/qemu_domain.c | 16 ++++++++++++++++
>  4 files changed, 34 insertions(+), 18 deletions(-)
...
> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
> index 3d6eef4..967890f 100644
> --- a/src/qemu/qemu_domain.c
> +++ b/src/qemu/qemu_domain.c
> @@ -738,6 +738,22 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
>          (def->os.arch == VIR_ARCH_S390 || def->os.arch == VIR_ARCH_S390X))
>          dev->data.chr->targetType = VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_VIRTIO;
>  
> +    /* auto generate unix socket path */
> +    if (dev->type == VIR_DOMAIN_DEVICE_CHR &&
> +        dev->data.chr->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL &&
> +        dev->data.chr->targetType == VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO &&
> +        dev->data.chr->source.type == VIR_DOMAIN_CHR_TYPE_UNIX &&
> +        !dev->data.chr->source.data.nix.path &&
> +        (cfg || (driver && (cfg = virQEMUDriverGetConfig(driver))))) {

I think this should fail if path is NULL and
(cfg || (driver && (cfg = virQEMUDriverGetConfig(driver)))) is not true.

On the other hand, do we actually need to check for this? Aren't both
cfg and driver guaranteed to be non-NULL at this point?

> +
> +        if (virAsprintf(&dev->data.chr->source.data.nix.path,
> +                        "%s/channel/target/%s.%s",
> +                        cfg->libDir, def->name,
> +                        dev->data.chr->target.name) < 0)
> +            goto no_memory;
> +        dev->data.chr->source.data.nix.listen = true;
> +    }
> +
>      ret = 0;
>  
>  cleanup:

Jirka