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

[Avi Kivity <avi@redhat.com>]

  On 10/19/2010 12:31 PM, Ian Molton wrote:
>
>> an virtualization@, many virtio developers live there.
>
> you mean virtualization@lists.osdl.org ?

Yes.

>
>> 2. should start with a patch to the virtio-pci spec to document what
>> you're doing
>
> Where can I find that spec?

http://ozlabs.org/~rusty/virtio-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.

The hypervisor and the guest can be changed independently.  The driver 
should be coded so that it doesn't depend on hypervisor implementation 
details.

-- 
error compiling committee.c: too many arguments to function