Re: [PATCH] iommu/vt-d: Set SSADE when attaching to a parent with dirty tracking

[Baolu Lu <baolu.lu@linux.intel.com>]

On 2024/2/8 17:14, Yi Liu wrote:
> Should set the SSADE (Second Stage Access/Dirty bit Enable) bit of the
> pasid entry when attaching a device to a nested domain if its parent
> has already enabled dirty tracking.
> 
> Fixes: 111bf85c68f6 ("iommu/vt-d: Add helper to setup pasid nested translation")
> Signed-off-by: Yi Liu <yi.l.liu@intel.com>
> ---
> base commit: 547ab8fc4cb04a1a6b34377dd8fad34cd2c8a8e3
> ---
>   drivers/iommu/intel/pasid.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
> index 3239cefa4c33..9be24bb762cf 100644
> --- a/drivers/iommu/intel/pasid.c
> +++ b/drivers/iommu/intel/pasid.c
> @@ -658,6 +658,8 @@ int intel_pasid_setup_nested(struct intel_iommu *iommu, struct device *dev,
>   	pasid_set_domain_id(pte, did);
>   	pasid_set_address_width(pte, s2_domain->agaw);
>   	pasid_set_page_snoop(pte, !!ecap_smpwc(iommu->ecap));
> +	if (s2_domain->dirty_tracking)
> +		pasid_set_ssade(pte);
>   	pasid_set_translation_type(pte, PASID_ENTRY_PGTT_NESTED);
>   	pasid_set_present(pte);
>   	spin_unlock(&iommu->lock);

The same fix should also be applied to the intel_pasid_setup_second()
path. Specifically, if a second-stage domain with dirty tracking enabled
attaches to a device, the corresponding entry in the pasid table should
also have the SSADE bit set.

Best regards,
baolu