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

[Gerd Hoffmann <kraxel@redhat.com>]

On 08/06/12 23:16, Benjamin Herrenschmidt wrote:
> On Mon, 2012-08-06 at 15:20 +0200, Gerd Hoffmann wrote:
>> There are discussions about re-doing the guest/host interface (command
>> rings etc) now and then, by adding a qxl2 device (or maybe even extend
>> stdvga), dropping a bunch of backward compatibility stuff in qxl.c.
>>
>> Sending the spice commands over virtio is certainly an option here.
>> I'm
>> not sure it is possible to drive virtio rings from userspace (Xorg
>> driver), but that issue should go away with the qxl kms driver in the
>> works.
> 
> Anything that gets rid of the qxl memory region API is welcome ;-) Some
> of that stuff is really gross.

Well, it is needed for sanity checking memory references (to images etc)
in qxl commands, so we can't just zap it.  But having a kms driver in
kernel space makes things easier again:  You could simply register a
single memory region for the guest ram, then basically use guest
physical addresses for qxl memory references.  qxl commands & data can
live in guest ram and you can stick references to the commands into
virtio rings ...

cheers,
  Gerd