Re: [Qemu-devel] [PATCH 2/2] qxl: add QXL_IO_UPDATE_MEM for guest S3&S4 support

[Gerd Hoffmann <kraxel@redhat.com>]

On 06/20/11 17:11, Alon Levy wrote:
> On Mon, Jun 20, 2011 at 04:07:59PM +0200, Gerd Hoffmann wrote:
>>>> What is the difference to one worker->stop() + worker->start() cycle?
>>>>
>>>
>>> ok, stop+start won't disconnect any clients either. But does stop render all waiting commands?
>>> I'll have to look, I don't know if it does.
>>
>> It does.  This is what qemu uses to flush all spice server state to
>> device memory on migration.
>>
>> What is the reason for deleting all surfaces?
>
> Making sure all references are dropped to pci memory in devram.

Ah, because the spice server keeps a reference to the create command 
until the surface is destroyed, right?

There is is QXL_IO_DESTROY_ALL_SURFACES + worker->destroy_surfaces() ...

The QXL_IO_UPDATE_MEM command does too much special stuff IMHO.
I also think we don't need to extend the libspice-server API.

We can add a I/O command which renders everything to device memory via 
stop+start.  We can zap all surfaces with the existing command + worker 
call.  We can add a I/O command to ask qxl to push the release queue 
head to the release ring.

Comments?

cheers,
   Gerd