Re: [PATCH v2 4/5] iommu/vt-d: Move pfsid and ats_qdep calculation to device probe path

Jacob Pan
2023-03-20T16:20:06Z

Hi BaoLu,

On Thu, 9 Mar 2023 10:56:38 +0800, Lu Baolu <baolu.lu@linux.intel.com>
wrote:

> They should be part of the per-device iommu private data initialization.
>
Reviewed-by: Jacob Pan <jacob.jun.pan@linux.intel.com>

> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
> drivers/iommu/intel/iommu.c | 26 +++++++++++---------------
> 1 file changed, 11 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 9ada12bf38dd..fb64ab8358a9 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -1406,20 +1406,6 @@ static void iommu_enable_pci_caps(struct
> device_domain_info *info) return;
>
> pdev = to_pci_dev(info->dev);
> - /* For IOMMU that supports device IOTLB throttling (DIT), we
> assign
> - * PFSID to the invalidation desc of a VF such that IOMMU HW can
> gauge
> - * queue depth at PF level. If DIT is not set, PFSID will be
> treated as
> - * reserved, which should be set to 0.
> - */
> - if (!ecap_dit(info->iommu->ecap))
> - info->pfsid = 0;
> - else {
> - struct pci_dev *pf_pdev;
> -
> - /* pdev will be returned if device is not a vf */
> - pf_pdev = pci_physfn(pdev);
> - info->pfsid = pci_dev_id(pf_pdev);
> - }
>
> /* The PCIe spec, in its wisdom, declares that the behaviour of
> the device if you enable PASID support after ATS support is
> @@ -1438,7 +1424,6 @@ static void iommu_enable_pci_caps(struct
> device_domain_info *info) !pci_enable_ats(pdev, VTD_PAGE_SHIFT)) {
> info->ats_enabled = 1;
> domain_update_iotlb(info->domain);
> - info->ats_qdep = pci_ats_queue_depth(pdev);
> }
> }
>
> @@ -4521,6 +4506,17 @@ static struct iommu_device
> *intel_iommu_probe_device(struct device *dev) dmar_ats_supported(pdev,
> iommu)) { info->ats_supported = 1;
> info->dtlb_extra_inval =
> dev_needs_extra_dtlb_flush(pdev); +
> + /*
> + * For IOMMU that supports device IOTLB
> throttling
> + * (DIT), we assign PFSID to the invalidation
> desc
> + * of a VF such that IOMMU HW can gauge queue
> depth
> + * at PF level. If DIT is not set, PFSID will be
> + * treated as reserved, which should be set to 0.
> + */
> + if (ecap_dit(iommu->ecap))
> + info->pfsid =
> pci_dev_id(pci_physfn(pdev));
> + info->ats_qdep = pci_ats_queue_depth(pdev);
> }
> if (sm_supported(iommu)) {
> if (pasid_supported(iommu)) {

Thanks,

Jacob