Re: [PATCH v9 12/25] iommu/arm-smmu-v3-kvm: Probe SMMU HW

[Nicolin Chen]

On Thu, Oct 15, 2026 at 08:08:43PM +0000, Mostafa Saleh wrote:
> Probe the SMMU features from the IDR registers with the functions shared
> with the kernel driver. SubstreamID bits and queue sizes are not needed
> here: CDs are not shadowed and the command queue is set up later.
> 
> The hypervisor requires two things the kernel driver does not:
> - Coherent table walks, reported by both firmware and IDR0.COHACC, as
>   it does no cache maintenance on its tables.
> - Nested translation, as the host keeps stage-1 and the hypervisor adds
>   stage-2.
> 
> Signed-off-by: Mostafa Saleh <smostafa@xxxxxxxxxx>
 
Reviewed-by: Nicolin Chen <nicolinc@xxxxxxxxxx>