[RFC PATCH 39/45] iommu/arm-smmu-v3-kvm: Initialize page table configuration

[Jean-Philippe Brucker]

Hi Mostafa,

On Wed, Mar 22, 2023 at 10:23:50AM +0000, Mostafa Saleh wrote:
> > +	/*
> > +	 * Stage-1 should be easy to support, though we do need to allocate a
> > +	 * context descriptor table.
> > +	 */
> > +	cfg = (struct io_pgtable_cfg) {
> > +		.fmt = ARM_64_LPAE_S2,
> > +		.pgsize_bitmap = smmu->pgsize_bitmap,
> > +		.ias = smmu->ias,
> > +		.oas = smmu->oas,
> > +		.coherent_walk = smmu->features & ARM_SMMU_FEAT_COHERENCY,
> > +	};
> > +
> > +	/*
> > +	 * Choose the page and address size. Compute the PGD size and number of
> > +	 * levels as well, so we know how much memory to pre-allocate.

(I also need to fix that comment, we're not getting the number of levels anymore)

> > +	 */
> > +	ret = io_pgtable_configure(&cfg, &size);
> size variable is overwritten here with pgd size, while used later on
> the assumption it still contains the SMMU MMIO size.
> This looks like it is not intended?

No it's a bug, thanks for spotting it. I'll try to update the pkvm/smmu
branch today with the other issues you reported

Thanks,
Jean