[Qemu-devel] Re: [PATCH] Implement a virtio GPU transport

[Ian Molton]

On 10/10/10 16:11, Avi Kivity wrote:
> On 10/06/2010 05:59 PM, Ian Molton wrote:
> > This patch implements a virtio-based transport for use by a
> > virtualised OpenGL passthrough implementation.
> >
> > The libGL and qemu-gl code to support this patch are available here:
> >
> > http://gitorious.org/vm-gl-accel/qemu-gl
> > http://gitorious.org/vm-gl-accel/qemu-libgl
> >
> >
> > Comments please!
>
> 1. copy qemu-devel

Ok, will do.

> an virtualization@, many virtio developers live there.

you mean address@hidden ?

> 2. should start with a patch to the virtio-pci spec to document what
> you're doing

Where can I find that spec?

> > + /* Transfer data */
> > + if (virtqueue_add_buf(vq, sg_list, o_page, i_page, (void *)1)>= 0) {
> > + virtqueue_kick(vq);
> > + /* Chill out until it's done with the buffer. */
> > + while (!virtqueue_get_buf(vq,&count))
> > + cpu_relax();
> > + }
> > +
>
> This is pretty gross, and will burn lots of cpu if the hypervisor
> processes the queue asynchronously.

It doesnt, at present... It could be changed fairly easily ithout 
breaking anything if that happens though.

-Ian