Re: [Qemu-devel] [PATCH] allocate pci id for mdpy

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Apr 26, 2018 at 11:00:28AM -0600, Alex Williamson wrote:
> On Thu, 26 Apr 2018 18:40:40 +0300
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
> 
> > On Thu, Apr 26, 2018 at 05:31:48PM +0200, Gerd Hoffmann wrote:
> > > On Thu, Apr 26, 2018 at 06:10:48PM +0300, Michael S. Tsirkin wrote:  
> > > > On Tue, Apr 24, 2018 at 08:38:57AM +0200, Gerd Hoffmann wrote:  
> > > > > mdpy is a sample pci device for vfio-mdev.  Not (yet) merged upstream,
> > > > > patch available here:
> > > > > 
> > > > > https://www.kraxel.org/cgit/linux/commit/?h=vfio-sample-display&id=6fd86cff3d7df38ab89625b16fdd6434b1c18749
> > > > > 
> > > > > Cc: Alex Williamson <alex.williamson@redhat.com>
> > > > > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>  
> > > > 
> > > > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > > > 
> > > > I presume this should be merged together with the
> > > > device implementation in qemu, or do you want this
> > > > in tree sooner?  
> > > 
> > > There isn't a device implementation in qemu.  It's a mdev device
> > > provided by the kernel.  Can be used with qemu using vfio. 
> > 
> > Why do we need a define in pci.h then?
> 
> Because we want to allocate the device ID rather than squat on an
> unused one and risk that it later conflicts with an another device.  Do
> we track device ID allocations from the RH vendor ID other than here in
> QEMU?  Thanks,
> 
> Alex

We have pci-ids.txt, yes. Unused macros just might get pruned down
the line. If you like, add a comment in pci.h saying 0xf is reserved for
mdpy.

-- 
MST