Re: [Qemu-devel] [virtio-dev] [PATCH 2/2] virtio-gpu/2d: add docs/specs/virtio-gpu.txt

[Dave Airlie]

>> Can the host refuse due to lack of resources?
>
> Yes.  virtgpu_ctrl_hdr.type in the response will be set to
> VIRTGPU_RESP_ERR_* then.  Current implementation does that only on
> malloc() failure, there is no accounting (yet) to limit the amout of
> memory the guest is allowed to allocate.

We do probably need to work out some sort of accounting system, it can
probably reliably only be a total value of resources, since we've no
idea if the host driver will store them in VRAM or main memory. Quite
how to fail gracefully is a question, probably need to report to the
guest what context did the allocation and see if we can destroy it.

>> > +
>> > +VIRTGPU_CMD_RESOURCE_INVAL_BACKING:
>> > +  Command: struct virtgpu_resource_inval_backing
>>
>> Why is it called INVAL_BACKING instead of DETACH_BACKING?  "Detach" is
>> logical since there is also an "attach" command.
>
> No particular reason I think.  Dave?
>

Not reason I can remember, I think I was thinking of having separate
inval and detach at one point, but it didn't really make any sense, so
renaming to detach is fine with me.

Dave.