[virglrenderer-devel] coherent memory access for virgl

[Gerd Hoffmann]

> > > My understanding is that we'd require that the VMM allocates all the
> > > memory of the machine in a single memfd region.
> >
> > Can be multiple memfd regions.  Otherwise correct.
> 
> By default, it seems QEMU allocates anonymous pages
> (qemu_anon_ram_alloc).  Is the "object
> memory-backend-memfd,id=mem1,size=1G" option needed to make udmabuf
> work?

For virtio-gpu yes, because all ram can be used as guest-side
ressource storage.

Side note: I also have some experimental code for vga, in that case the
vga emulation can take care to allocate the vga pci memory bar backing
storage using memfd so no specific configuration is needed in that case.

cheers,
  Gerd