Re: [PATCH v5 4/7] iommu: Decouple iommu_domain_alloc() from bus ops

[Jerry Snitselaar]

On Wed, Oct 11, 2023 at 07:14:51PM +0100, Robin Murphy wrote:
> As the final remaining piece of bus-dependent API, iommu_domain_alloc()
> can now take responsibility for the "one iommu_ops per bus" rule for
> itself. It turns out we can't safely make the internal allocation call
> any more group-based or device-based yet - that will have to wait until
> the external callers can pass the right thing - but we can at least get
> as far as deriving "bus ops" based on which driver is actually managing
> devices on the given bus, rather than whichever driver won the race to
> register first.
> 
> This will then leave us able to convert the last of the core internals
> over to the IOMMU-instance model, allow multiple drivers to register and
> actually coexist (modulo the above limitation for unmanaged domain users
> in the short term), and start trying to solve the long-standing
> iommu_probe_device() mess.
> 
> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
> 
> ---
> 
> v5: Rewrite, de-scoping to just retrieve ops under the same assumptions
>     as the existing code.
> ---

Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>