Re: [Qemu-devel] [PATCH] hw/virtio-serial-bus: replay guest open on destination

[Anthony Liguori]

Amit Shah <address@hidden> writes:

> On (Sun) 25 Nov 2012 [15:39:14], Alon Levy wrote:
>> When migrating a host with with a spice agent running the mouse becomes
>> non operational after the migration due to the agent state being
>> inconsistent between the guest and the client if the client is using
>> semi-seamless or switch host migration.
>> 
>> After migration the target client has never received the guest_open
>> initiated spice message. Virtio-serial holds this state information and
>> migrates it, so replay that over the chardev post migration. Fix is not
>> spice specific but spice is the only client that cares about it.
>
> Thanks for continuing to pursue this :)
>
>> rhbz #725965.
>> ---
>>  hw/virtio-serial-bus.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>> 
>> diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
>> index efa8a81..ccce1fa 100644
>> --- a/hw/virtio-serial-bus.c
>> +++ b/hw/virtio-serial-bus.c
>> @@ -641,6 +641,7 @@ static void virtio_serial_post_load_timer_cb(void 
>> *opaque)
>>      VirtIOSerial *s = opaque;
>>      VirtIOSerialPort *port;
>>      uint8_t host_connected;
>> +    VirtIOSerialPortClass *vsc;
>>  
>>      for (i = 0 ; i < s->post_load.nr_active_ports; ++i) {
>>          port = s->post_load.connected[i].port;
>> @@ -653,6 +654,11 @@ static void virtio_serial_post_load_timer_cb(void 
>> *opaque)
>>              send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN,
>>                                 port->host_connected);
>>          }
>> +        vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port);
>> +        if (port->guest_connected && vsc->guest_open) {
>> +            /* replay guest open */
>> +            vsc->guest_open(port);
>> +        }
>
> I think the last time we discussed this, my objection was the guest
> isn't really doing an open again, and since spice depends on the
> guest's connectedness, spice should have a post-load hook or a similar
> bh that would query virtio-serial for guest connectedness status, and,
> if connected, do whatever setup is necessary.

Agreed.

Regards,

Anthony Liguori

>
> Adding Gerd and Markus as I think they were involved in the discussion
> last time as well.
>
>               Amit