RE: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and allocation APIs

Liu, Yi L
2021-03-31T08:38:38Z

> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Tuesday, March 30, 2021 9:43 PM
[..]
> No, the mdev device driver must enforce this directly. It is the one
> that programms the physical shared HW, it is the one that needs a list
> of PASID's it is allowed to program *for each mdev*
>
> ioasid_set doesn't seem to help at all, certainly not as a concept
> tied to /dev/ioasid.
>

As replied in another thread. We introduced ioasid_set based on the
motivation to have per-VM ioasid track, which is required when user
space tries to bind an ioasid with a device. Should ensure the ioasid
it is using was allocated to it. otherwise, we may suffer inter-VM ioasid
problem. It may not necessaty to be ioasid_set but a per-VM ioasid track
is necessary.

Regards,
Yi Liu