Re: [XEN PATCH v5] xen/arm: ffa: reclaim shared memory on guest destroy

[Julien Grall <julien@xxxxxxx>]

Hi,

On 13/02/2024 11:13, Jens Wiklander wrote:
> When an FF-A enabled guest is destroyed it may leave behind memory
> shared with SPs. This memory must be reclaimed before it's reused or an
> SP may make changes to memory used by a new unrelated guest. So when the
> domain is teared down add FF-A requests to reclaim all remaining shared
> memory.
>
> SPs in the secure world are notified using VM_DESTROYED that a guest has
> been destroyed. An SP is supposed to relinquish all shared memory to allow
> reclaiming the memory. The relinquish operation may need to be delayed if
> the shared memory is for instance part of a DMA operation.
>
> The domain reference counter is increased when the first FF-A shared
> memory is registered and the counter is decreased again when the last
> shared memory is reclaimed. If FF-A shared memory registrations remain
> at the end of of ffa_domain_teardown() a timer is set to try to reclaim
> the shared memory every second until the memory is reclaimed.
>
> A few minor style fixes with a removed empty line here and an added new
> line there.
>
> Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
> Reviewed-by: Bertrand Marquis <bertrand.marquis@xxxxxxx>
This is now committed.

Cheers,

--
Julien Grall