Re: Adjusting the default ROM option for SEV guests

[Gerd Hoffmann]

On Wed, Jul 06, 2022 at 04:57:40PM +0200, Claudio Fontana wrote:
> Hello all
> 
> any comment on this one? It seems it would make sense to disable option roms 
> for SEV by default in QEMU, any feedback anyone?
> 
> Thanks,
> 
> Claudio
> 
> On 5/11/22 13:30, Vasily Ulyanov wrote:
> > Hello QEMU devs,
> > 
> > Currently to launch an SEV guest there are certain requirements for the VM
> > configuration. One such is that ROM option needs to be disabled for 
> > virtio-net
> > devices [1].

Should be easy to fix on the firmware side.  TDX has the same
requirement and the code is already there, so this should be a
one-liner in OvmfPkg/IncompatiblePciDeviceSupportDxe

Independent from that we might consider switching virtio to
pxe-virtio.rom (i.e. bios-only instead of bios+uefi) for everyone
because the uefi firmware comes with a virtio-net driver included.

take care,
  Gerd