[Qemu-devel] [PATCH v4 0/7] vfio: add display support

[Zhang, Tina]

> -----Original Message-----
> From: Zhenyu Wang [mailto:zhenyuw at linux.intel.com]
> Sent: Friday, February 23, 2018 10:43 AM
> To: Gerd Hoffmann <kraxel at redhat.com>
> Cc: Alex Williamson <alex.williamson at redhat.com>; Kirti Wankhede
> <kwankhede at nvidia.com>; intel-gvt-dev at lists.freedesktop.org; qemu-
> devel at nongnu.org; Zhang, Tina <tina.zhang at intel.com>
> Subject: Re: [Qemu-devel] [PATCH v4 0/7] vfio: add display support
> 
> On 2018.02.22 10:30:55 +0100, Gerd Hoffmann wrote:
> >   Hi,
> >
> > > Nice! Seems to be the last missing gap for local spice with cursor
> > > dmabuf support, we'll do more testing on that for sure. Btw, another
> > > method might be to add direct cursor dmabuf passing for spice as gl
> > > output, is that correct way?
> >
> > Passing on the cursor sprite needs the hotspot information, so spice
> > client can position the cursor correctly.  I didn't got hotspot
> > information in my testing yet, but maybe the guest kernel was too old.
> > Is that supported meanwhile?  If so, which kernel version is needed?
> >
> 
> Current gvt dmabuf doesn't support true hotspot info yet which requires some
> pv info update as we can't get it from hw state. Tina is pursuing that.
Indeed. Guest OS needs to use pv info to deliver the hotspot info to host. And so far, only Windows igfx driver can support it.
With the following patch, host userspace can get the valid hotspot info if it is supported by guest driver (e.g. Windows), or invalid hotspot info when unsupported.
https://lists.freedesktop.org/archives/intel-gvt-dev/2018-February/003169.html

BR,
Tina
> 
> > Spice already has support for setting pointers, we can simply use
> > that, at least initially.  Doesn't use dma-bufs.  If it turns out to
> > be a performance issue we can add support for using dma-bufs instead,
> > but that needs spice server changes.
> >
> > > And really like to see dmabuf support could be in upstream soon. Do
> > > you have any predict for which qemu version?
> >
> > I want have this in 2.12, at least the current, initial version.
> > Improved cursor support might take a little longer.
> >
> 
> Good to know. Thanks!
> 
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