Re: [PATCH v1 0/1] s390: virtio-ccw: PV needs VIRTIO I/O device protection

From: Pierre Morel
Date: Fri Aug 07 2020 - 10:26:11 EST




On 2020-08-06 17:47, Cornelia Huck wrote:
On Thu, 6 Aug 2020 16:23:01 +0200
...
This does work, and I'm tempted to queue this patch, but I'm wondering
whether we need to give up on a cross-architecture solution already
(especially keeping in mind that ccw is the only transport that is
really architecture-specific).

I know that we've gone through a few rounds already, and I'm not sure
whether we've been there already, but:

Could virtio_finalize_features() call an optional
arch_has_restricted_memory_access() function and do the enforcing of
IOMMU_PLATFORM? That would catch all transports, and things should work
once an architecture opts in. That direction also shouldn't be a
problem if virtio is a module.

Yes thanks, I rework it in this direction.


--
Pierre Morel
IBM Lab Boeblingen