Re: [Qemu-devel] [PATCH 0 of 3] vnc and vga improvements

[Anthony Liguori <anthony@codemonkey.ws>]

Gerd Hoffmann wrote:
> Anthony Liguori wrote:
>   
>> Stefano Stabellini wrote:
>>     
>> I have mixed feelings about this.  On the one hand, reducing the copying
>> is a good thing.  On the other hand, we pretty much make it impossible
>> to ever support multiple clients.
>>     
>
> Getting rid of the color space conversions is a good thing, even in case
> we can't drop the separate buffers and the memcpys.  Right now the vnc
> server runs at 32bit unconditionally.  Having it run at 16bpp in case
> the guest uses 16bpp is still a win because we (a) have to handle less
> memory and (b) can to a straight copy instead of a pixel conversion.
>   

It's not as big of a win as it seems as there is only one client that 
can handle this ATM :-)

> And maybe the buffer sharing can be implemented in a way that we can
> turn it on and off at runtime?  So the common case of at most one client
> can run with buffer sharing, otherwise we copy to per-client buffers?
>   

Yes, I would like this.  I haven't yet looked closely at the patches, 
but if this is the case, I would be inclined to apply them.

Regards,

Anthony Liguori

> I'm not a vnc protocol expert though.
>
> Looking at the patches, it seems buffer sharing is optional already
> (usage depending on the color depth right now it seems).
>
> cheers,
>   Gerd
>
>
>
>
>