Re: [PATCH 2/2] iommu: arm-smmu-v3: Report domain nesting info reuqired for stage1

[Vivek Gautam]

Hi Eric,

On Fri, Feb 12, 2021 at 11:44 PM Auger Eric <eric.auger@xxxxxxxxxx> wrote:
>
> Hi Vivek,
>
> On 2/12/21 11:58 AM, Vivek Gautam wrote:
> > Update nested domain information required for stage1 page table.
>
> s/reuqired/required in the commit title

Oh! my bad.

> >
> > Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxx>
> > ---
> >  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 16 ++++++++++++++--
> >  1 file changed, 14 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> > index c11dd3940583..728018921fae 100644
> > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> > @@ -2555,6 +2555,7 @@ static int arm_smmu_domain_nesting_info(struct arm_smmu_domain *smmu_domain,
> >                                       void *data)
> >  {
> >       struct iommu_nesting_info *info = (struct iommu_nesting_info *)data;
> > +     struct arm_smmu_device *smmu = smmu_domain->smmu;
> >       unsigned int size;
> >
> >       if (!info || smmu_domain->stage != ARM_SMMU_DOMAIN_NESTED)
> > @@ -2571,9 +2572,20 @@ static int arm_smmu_domain_nesting_info(struct arm_smmu_domain *smmu_domain,
> >               return 0;
> >       }
> >
> > -     /* report an empty iommu_nesting_info for now */
> > -     memset(info, 0x0, size);
> > +     /* Update the nesting info as required for stage1 page tables */
> > +     info->addr_width = smmu->ias;
> > +     info->format = IOMMU_PASID_FORMAT_ARM_SMMU_V3;
> > +     info->features = IOMMU_NESTING_FEAT_BIND_PGTBL |
> I understood IOMMU_NESTING_FEAT_BIND_PGTBL advertises the requirement to
> bind tables per PASID, ie. passing iommu_gpasid_bind_data.
> In ARM case I guess you plan to use attach/detach_pasid_table API with
> iommu_pasid_table_config struct. So I understood we should add a new
> feature here.

Right, the idea is to let vfio know that we support pasid table binding, and
I thought we could use the same flag. But clearly that's not the case.
Will add a new feature.

> > +                      IOMMU_NESTING_FEAT_PAGE_RESP |
> > +                      IOMMU_NESTING_FEAT_CACHE_INVLD;
> > +     info->pasid_bits = smmu->ssid_bits;
> > +     info->vendor.smmuv3.asid_bits = smmu->asid_bits;
> > +     info->vendor.smmuv3.pgtbl_fmt = ARM_64_LPAE_S1;
> > +     memset(&info->padding, 0x0, 12);
> > +     memset(&info->vendor.smmuv3.padding, 0x0, 9);
> > +
> >       info->argsz = size;
> > +
> spurious new line

Sure, will remove it.

Best regards
Vivek

> >       return 0;
> >  }
> >
> >
>
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