On 3/15/22 10:38 AM, Jason Gunthorpe wrote:
On Tue, Mar 15, 2022 at 09:49:01AM -0400, Matthew Rosato wrote:
The rationale for splitting steps 1 and 2 are that VFIO_SET_IOMMU doesn't
have a mechanism for specifying more than the type as an arg, no? Otherwise
yes, you could specify a kvm fd at this point and it would have some other
advantages (e.g. skip notifier). But we still can't use the IOMMU for
mapping until step 3.
Stuff like this is why I'd be much happier if this could join our
iommfd project so we can have clean modeling of the multiple iommu_domains.
I'd certainly be willing to collaborate so feel free to loop me in on
the discussions; but I got the impression that iommufd is not close to
ready (maybe I'm wrong?) -- if so I really don't want to completely
delay this zPCI support behind it as it has a significant benefit for
kvm guests on s390x :(
