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

[Anthony Liguori]

Avi Kivity <address@hidden> writes:

> On 07/30/2012 02:54 PM, Benjamin Herrenschmidt wrote:
>>> 
>>> > 
>>> > We can also make the fbdev/fbcon driver do the swapping in SW, but it's
>>> > a relatively unusual code path and I don't think it works properly with
>>> > X, I don't think it can be made to work properly with the generic X KMS
>>> > at this point.
>>> > 
>>> > Now, cirrusdrmfb is already specific to the qemu cirrus variant in
>>> > several ways, I wouldn't mind keeping it that way and if we "fix" the
>>> > endianness model, maybe having a "hidden" register to flip it back to
>>> > it's current mode of operation that cirrusdrmfb would use...
>>> 
>>> That's possible, but why not go all the way to qxl?
>>>
>>> That will give you better graphics performance with no need to hack.
>> 
>> Well, qxl is pretty awful from what I can see so far. I'm more tempted
>> to continue improving qemu-vga, adding a virtio transport, and maybe
>> adding a way to tunnel spice into it if that makes sense but so far,
>> that's stuff was designed for Windows as far as I can tell and is pretty
>> horrible whatever way you look at it...
>
> Let's balkanize some more then?

Minor improvements to stdvga actual help qxl (presumably).  qxl still
provides a vga interface which is used when guest drivers aren't
available.

It's not clear to me why it doesn't enable VBE but presumably if it did,
then accelerations could be mapped through VBE.

>
> 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.

Actually, Gerd et al have expressed interest in moving to a virtio-based
device model for Spice in the past.

I think done correctly, it could help bring graphics to other platforms
like S390 where PCI doesn't exist and will never exist.

Regards,

Anthony Liguori

>
> http://spice-space.org/page/DRM
>
> -- 
> error compiling committee.c: too many arguments to function