Re: [XEN PATCH v6 0/7] FF-A notifications

[Julien Grall <julien@xxxxxxx>]

Hi Bertrand,

On 10/06/2024 16:54, Bertrand Marquis wrote:
> Hi Jens,
>
> > On 10 Jun 2024, at 08:53, Jens Wiklander <jens.wiklander@xxxxxxxxxx> wrote:
> >
> > Hi,
> >
> > This patch set adds support for FF-A notifications. We only support
> > global notifications, per vCPU notifications remain unsupported.
> >
> > The first three patches are further cleanup and can be merged before the
> > rest if desired.
> >
> > A physical SGI is used to make Xen aware of pending FF-A notifications. The
> > physical SGI is selected by the SPMC in the secure world. Since it must not
> > already be used by Xen the SPMC is in practice forced to donate one of the
> > secure SGIs, but that's normally not a problem. The SGI handling in Xen is
> > updated to support registration of handlers for SGIs that aren't statically
> > assigned, that is, SGI IDs above GIC_SGI_MAX.
> >
> > The patch "xen/arm: add and call init_tee_secondary()" provides a hook for
> > register the needed per-cpu interrupt handler in "xen/arm: ffa: support
> > notification".
> >
> > The patch "xen/arm: add and call tee_free_domain_ctx()" provides a hook for
> > later freeing of the TEE context. This hook is used in "xen/arm: ffa:
> > support notification" and avoids the problem with TEE context being freed
> > while we need to access it when handling a Schedule Receiver interrupt. It
> > was suggested as an alternative in [1] that the TEE context could be freed
> > from complete_domain_destroy().
> >
> > [1] 
> > https://lore.kernel.org/all/CAHUa44H4YpoxYT7e6WNH5XJFpitZQjqP9Ng4SmTy4eWhyN+F+w@xxxxxxxxxxxxxx/
> >
> > Thanks,
> > Jens
> All patches are now reviewed and/or acked so I think they can get in for the 
> release.
This would need a release-ack from Oleksii (I can't seem to find already 
one).
As we discussed last week, I am fine with the idea to merge the FFA 
patches as the feature is tech-preview. But there are some changes in 
the arm generic code. Do you (or Jens) have an assessment of the risk of 
the changes?
Cheers,

--
Julien Grall