> From: Nicolin Chen <nicolinc@xxxxxxxxxx> > Sent: Sunday, December 17, 2023 2:49 AM > > On Fri, Dec 15, 2023 at 12:01:19PM +0800, Yi Liu wrote: > > On 2023/12/15 11:32, Nicolin Chen wrote: > > > On Fri, Dec 15, 2023 at 03:04:44AM +0000, Tian, Kevin wrote: > > > > > From: Nicolin Chen <nicolinc@xxxxxxxxxx> > > > > > Sent: Friday, December 15, 2023 10:28 AM > > > > > On Fri, Dec 15, 2023 at 01:50:07AM +0000, Tian, Kevin wrote: > > > > > > > From: Liu, Yi L <yi.l.liu@xxxxxxxxx> > > > > > > > Sent: Thursday, December 14, 2023 7:27 PM > > > > > > > > > > > > > > On 2023/11/17 21:18, Yi Liu wrote: > > > > > > and for this error reporting case what we actually require is the > > > > > > reverse map i.e. pRID->vRID. Not sure whether we can leverage the > > > > > > same RID mapping uAPI as for ARM/AMD but ignore viommu_id > > > > > > and then store vRID under device_domain_info. a bit tricky on > > > > > > life cycle management and also incompatible with SIOV... > > > > > > > > > > One thing that I am not very clear here: since both vRID and dev_id > > > > > are given by the VMM, shouldn't it already know the mapping if the > > > > > point is to translate (pRID->)dev_id->vRID? > > > > > > > > > > > > > it's true for current Qemu. > > > > > > > > but there is plan to support Qemu accepting a fd passed by Libvirt. > > > > In that case Qemu even doesn't see the sysfs path hence is not > > > > aware of pRID. otherwise yes we could leave the translation to > > > > VMM instead. > > > > > > I think I misread Yi's narrative: dev_id is a working approach > > > for VMM to convert to a vRID, while he is asking for a better > > > alternative :) > > > > In concept, dev_id works, but in reality we have problem to get a dev_id > > for a given device in intel iommu driver, hence I'm asking for help here. :) > > Yea, I got that. > > Would it be possible for us to postpone this error report in the > vtd driver? > that is the plan. We'll still report error code but no dev_id error data. this is allowed by vtd spec.
