RE: [PATCH RFCv1 04/14] iommufd: Add struct iommufd_viommu and iommufd_viommu_ops

Tian, Kevin
2024-05-24T02:37:03Z

> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Thursday, May 23, 2024 8:59 PM
>
> > > now. If someone needs them linked someday we can add a viommu_id to
> > > the create pri queue command.
> >
> > I'm more worried about the potential conflict between the vqueue
> > object here and the fault queue object in Baolu's series, if we want
> > to introduce vIOMMU concept to platforms which lack of the hw
> > support.
>
> I assume the vPPRLog will steal all the PRI before it reaches the
> kernel, so once this is turned on Lu's path won't see anything.
>
> I don't know if AMD can turn vPPRLog on individually or if it is a
> whole package once they switch on VIOMMU..
>

their spec says:
"
This feature is supported if MMIO Offset 0030h[vIommuSup]=1. When
enabled, DTE[vImuEn]=1 indicates the guest owning this device is a
vIOMMU enabled guest, and IOMMU should write event and peripheral
page requests associated with this device into the guest data structures.
"

so it's configured per device.