Re: PCI passthrough on arm Design Session MoM

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Thu, Jul 09, 2020 at 10:29:52AM +0000, Bertrand Marquis wrote:
> 
> 
> > On 8 Jul 2020, at 14:32, Roger Pau Monné <roger.pau@xxxxxxxxxx> wrote:
> > 
> > On Wed, Jul 08, 2020 at 12:55:36PM +0000, Bertrand Marquis wrote:
> >> Hi,
> >> 
> >> Here are the notes we took during the design session around PCI devices 
> >> passthrough on Arm.
> >> Feel free to comment or add anything :-)
> >> 
> >> Bertrand
> >> 
> >> PCI devices passthrough on Arm Design Session
> >> ======================================
> >> 
> >> Date: 7/7/2020
> >> 
> >> - X86 VPCI support  is for the PVH guest .
> > 
> > Current vPCI is only for PVH dom0. We need to decide what to do for
> > PVH domUs, whether we want to use vPCI or xenpt from Paul:
> > 
> > http://xenbits.xen.org/gitweb/?p=people/pauldu/xenpt.git;a=summary
> > 
> > Or something else. I think this decision also needs to take into
> > account Arm.
> 
> We are currently using vpci for guests.
> But we could also look into xenpt but from a quick check it does require a 
> Dom0 which would defeat the Dom0less use case.

Right, you need a hardware domain in order to use xenpt. Note that
AFAICT you would also need a hardware domain in order to do the
placement of BARs for example if the firmware is not doing it for you.

Likely better to discuss all this against a design document instead of
raising specific issues here I guess :).

Roger.