[PATCH v1 2/2] qemu_process: continue to process fakereboot after restarting libvirtd

[Bihong Yu]

On 2021/11/10 17:32, Michal Prívozník wrote:
> On 10/25/21 11:04 AM, Bihong Yu wrote:
>> During the vm rebooting, the vm could be paused if the libvirtd is
>> restarted for some reason, which is not expected. We need continue
>> fakereboot process if fakereboot flags is true and the vm is in
>> paused-user status.
>>
>> Signed-off-by: Bihong Yu <yubihong at huawei.com>
>> ---
>>  src/qemu/qemu_process.c | 10 ++++++----
>>  1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
>> index 832ce164fb..a758b96fa6 100644
>> --- a/src/qemu/qemu_process.c
>> +++ b/src/qemu/qemu_process.c
>> @@ -8742,13 +8742,15 @@ qemuProcessReconnect(void *opaque)
>>          goto error;
>>      }
>>  
>> -    /* In case the domain shutdown while we were not running,
>> -     * we need to finish the shutdown process. And we need to do it after
>> -     * we have virQEMUCaps filled in.
>> +    /* In case the domain shutdown or fake reboot while we were not running,
>> +     * we need to finish the shutdown or fake reboot process. And we need to
>> +     * do it after we have virQEMUCaps filled in.
>>       */
>>      if (state == VIR_DOMAIN_SHUTDOWN ||
>>          (state == VIR_DOMAIN_PAUSED &&
>> -         reason == VIR_DOMAIN_PAUSED_SHUTTING_DOWN)) {
>> +         reason == VIR_DOMAIN_PAUSED_SHUTTING_DOWN) ||
>> +        (priv->fakeReboot && state == VIR_DOMAIN_PAUSED &&
>> +         reason == VIR_DOMAIN_PAUSED_USER)) {
> 
> One thing that I don't quite understand is why this new condition checks
> for state or reason. I could understand the reason a bit (because domain
> is paused after SHUTDOWN event), but the reason? Can you elaborate please?

Hi, Michal. Thank you for your reply.
  The reason is that: while libvirt reboot vm with ACPI mode, the vm will
undergo the following state changes:
	running -> shutdown -> prelaunch -> running
  If libvirtd reboot after vm prelaunch status and before vm running status,
the qemuProcessUpdateState() will update the vm status to 'VIR_DOMAIN_PAUSED'
and reason to 'VIR_DOMAIN_PAUSED_USER' according to the qemuMonitorGetStatus()
returning result in qemuProcessReconnect().
  So, we need to recognize this scenario and continue to finish rebooting
process.

> 
>>          VIR_DEBUG("Finishing shutdown sequence for domain %s",
>>                    obj->def->name);
>>          qemuProcessShutdownOrReboot(driver, obj);
>>
> 
> Michal
> 
> .
>