Re: [PATCH v6 15/18] drm/virtio: rework virtio_gpu_transfer_to_host_ioctl fencing

From: Gerd Hoffmann
Date: Fri Jul 05 2019 - 10:07:54 EST


> > > ... 3d case passes the objs list to virtio_gpu_cmd_transfer_to_host_3d,
> > > so it gets added to the vbuf and released when the command is finished.
> > Why doesn't this apply to virtio_gpu_cmd_transfer_to_host_2d?
>
> Hmm, yes, makes sense to handle both the same way.
>
> With virgl=off qemu processes the commands from the guest
> synchronously, so it'll work fine as-is. So you can't hit
> the theoretical race window in practice. But depending
> on that host-side implementation detail isn't a good idea
> indeed.

Branch with incremental fixes:
https://git.kraxel.org/cgit/linux/log/?h=drm-virtio-kill-ttm

I'll be offline three weeks now, will resume this when I'm back.

cheers,
Gerd