[libvirt] [PATCH 1/2] libxl: don't attempt to probe a non-existent emulator

[Jim Fehlig]

On 05/13/2016 01:41 AM, Ján Tomko wrote:
> On Thu, May 12, 2016 at 02:40:28PM -0600, Jim Fehlig wrote:
>> When probing the <emulator> with '-help' to determine if
>> it is the old qemu, errors are reported if the emulator
>> doesn't exist
>>
>> libvirt:  error : internal error: Child process
>> (/usr/lib/xen/bin/qemu-dm -help) unexpected exit status 127:
>> libvirt:  error : cannot execute binary /usr/lib/xen/bin/qemu-dm:
>> No such file or directory
>>
>> Avoid the probe if the specified emulator doesn't exist,
>> squelching the error. There is no behavior change since
>> libxlDomainGetEmulatorType() would return
>> LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN if the probe failed
>> via virCommandRun().
>>
>> Signed-off-by: Jim Fehlig <jfehlig at suse.com>
>> ---
>>  src/libxl/libxl_conf.c | 3 +++
>>  1 file changed, 3 insertions(+)
>>
> ACK. If we don't treat it as an error, we should not report it as one.

Nod. libxlDomainGetEmulatorType() is just a best effort to see if the emulator
is the old xen fork of qemu. Like libxl, if that effort fails we assume upstream
qemu. Note that we do verify in libxlMakeDomBuildInfo() that the specified
emulator actually exists before creating the domain.

Regards,
Jim