Re: [PATCH] Implement a virtio GPU transport

Ian Molton
2010-10-19T10:37:16Z

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 virtualization@lists.osdl.org ?

> 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