Re: [Qemu-devel] Cirrus bugs vs endian: how two bugs cancel each other out

[Alon Levy]

On Mon, Jul 30, 2012 at 10:08:07PM +1000, Benjamin Herrenschmidt wrote:
> On Mon, 2012-07-30 at 14:58 +0300, Avi Kivity wrote:
> > Let's balkanize some more then?
> > 
> > No, qxl is our paravirt vga, we should improve it instead of spawning
> > new ones (which will be horrible in the eyes of the next person to look
> > at them).  You should also be getting the drm driver for free.
> > 
> > http://spice-space.org/page/DRM
> 
> "Free" is a big word here, I wouldn't be surprised if it was totally
> endian busted :-)
> 
> Why so much effort into a bad design on top of a crack transport btw ?
Could you elaborate about the design and transport issues that you see?

> Is it just RH politics of there's a good reason hiding somewhere ? Some
No politics AFAIK. Spice code may suck but it's doing a good job while
sucking, so we prefer to fix it unless a good design that makes it
easier to rebuild from scratch comes along. I'm all ears.

> kind of morbid fascination for anything Windows ?
We do have bad linux performance but the is work going to improve it, by
adding RENDER implementation to our driver and protocol additions, among
others.

> 
> People I've talked to around in the community seem to agree that some
> minor improvements on qemu-vga are worthwhile, so I'm doing them,
> nothing drastic, mostly having a mirror of the legacy IO registers in an
> MMIO BAR so it's more usable for non-x86 platforms, and I'm about to add
> some simplistic 2D blit facility so we can have a semi-decent fb console
> over vnc. I can trivially do an equivalent of cirrusdrmfb for it so we
> get X mode setting / RandR.
> 
> That gives us a baseline for mostly unaccelerated 2D.
> 
> Something tells me that getting that spice/qxl gunk will be more than a
> trivial effort (but I might be wrong) and I'm reluctant to start
> committing effort on it since so far I yet have to see it being actually
> picked up by people.

I'll be happy to elaborate on any part of qxl/spice that I understand
and help you help us improve it.

> 
> Cheers,
> Ben.
> 
>  
> 
>