Re: [RFC v2] /dev/iommu uAPI proposal

From: Jason Gunthorpe
Date: Thu Jul 15 2021 - 08:48:20 EST

On Thu, Jul 15, 2021 at 06:49:54AM +0000, Tian, Kevin wrote:

> No. You are right on this case. I don't think there is a way to
> differentiate one mdev from the other if they come from the
> same parent and attached by the same guest process. In this
> case the fault could be reported on either mdev (e.g. the first
> matching one) to get it fixed in the guest.

If the IOMMU can't distinguish the two mdevs they are not isolated
and would have to share a group. Since group sharing is not supported
today this seems like a non-issue