On Fri, Nov 19, 2021 at 07:18:00PM +0000, Sean Christopherson wrote:

On Fri, Nov 19, 2021, David Hildenbrand wrote:

quoted

On 19.11.21 16:19, Jason Gunthorpe wrote:

quoted

As designed the above looks useful to import a memfd to a VFIO
container but could you consider some more generic naming than calling
this 'guest' ?

+1 the guest terminology is somewhat sob-optimal.

For the F_SEAL part, maybe F_SEAL_UNMAPPABLE?

Perhaps INACCESSIBLE?

No ideas for the kernel API, but that's also less concerning since
it's not set in stone.  I'm also not sure that dedicated APIs for
each high-ish level use case would be a bad thing, as the semantics
are unlikely to be different to some extent.  E.g. for the KVM use
case, there can be at most one guest associated with the fd, but
there can be any number of VFIO devices attached to the fd.

Even the kvm thing is not a hard restriction when you take away
confidential compute.

Why can't we have multiple KVMs linked to the same FD if the memory
isn't encrypted? Sure it isn't actually useful but it should work
fine.

Supporting only one thing is just a way to avoid having a linked list
of clients to broadcast invalidations too - for instance by using a
standard notifier block...

Also, how does dirty tracking work on this memory?

Jason