Re: [RFC v2 PATCH 01/13] mm/shmem: Introduce F_SEAL_GUEST

From: Jason Gunthorpe
Date: Mon Nov 22 2021 - 08:31:51 EST

On Mon, Nov 22, 2021 at 10:26:12AM +0100, David Hildenbrand wrote:

> I do wonder if we want to support sharing such memfds between processes
> in all cases ... we most certainly don't want to be able to share
> encrypted memory between VMs (I heard that the kernel has to forbid
> that). It would make sense in the use case you describe, though.

If there is a F_SEAL_XX that blocks every kind of new access, who
cares if userspace passes the FD around or not?