Re: [PATCH v3 07/16] iommu/vt-d: assign PFSID in device TLB invalidation

Lu Baolu
2017-12-05T05:45:03Z

Hi,

On 11/18/2017 02:55 AM, Jacob Pan wrote:
> When SRIOV VF device IOTLB is invalidated, we need to provide
> the PF source SID such that IOMMU hardware can gauge the depth
> of invalidation queue which is shared among VFs. This is needed
> when device invalidation throttle (DIT) capability is supported.
>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
> drivers/iommu/intel-iommu.c | 13 +++++++++++++
> include/linux/intel-iommu.h | 3 +++
> 2 files changed, 16 insertions(+)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index 000b2b3..e1bd219 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -1459,6 +1459,19 @@ static void iommu_enable_dev_iotlb(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 if (pdev && pdev->is_virtfn) {
> + if (ecap_dit(info->iommu->ecap))

Isn't this condition always true when it comes here?

Best regards,
Lu Baolu

> + dev_warn(&pdev->dev, "SRIOV VF device IOTLB enabled without flow control\n");
> + info->pfsid = PCI_DEVID(pdev->physfn->bus->number, pdev->physfn->devfn);
> + } else
> + info->pfsid = PCI_DEVID(info->bus, info->devfn);
>
> #ifdef CONFIG_INTEL_IOMMU_SVM
> /* The PCIe spec, in its wisdom, declares that the behaviour of
> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
> index 7f05e36..6956a4e 100644
> --- a/include/linux/intel-iommu.h
> +++ b/include/linux/intel-iommu.h
> @@ -112,6 +112,7 @@
> * Extended Capability Register
> */
>
> +#define ecap_dit(e) ((e >> 41) & 0x1)
> #define ecap_pasid(e) ((e >> 40) & 0x1)
> #define ecap_pss(e) ((e >> 35) & 0x1f)
> #define ecap_eafs(e) ((e >> 34) & 0x1)
> @@ -285,6 +286,7 @@ enum {
> #define QI_DEV_IOTLB_SID(sid) ((u64)((sid) & 0xffff) << 32)
> #define QI_DEV_IOTLB_QDEP(qdep) (((qdep) & 0x1f) << 16)
> #define QI_DEV_IOTLB_ADDR(addr) ((u64)(addr) & VTD_PAGE_MASK)
> +#define QI_DEV_IOTLB_PFSID(pfsid) (((u64)(pfsid & 0xf) << 12) | ((u64)(pfsid & 0xff0) << 48))
> #define QI_DEV_IOTLB_SIZE 1
> #define QI_DEV_IOTLB_MAX_INVS 32
>
> @@ -475,6 +477,7 @@ struct device_domain_info {
> struct list_head global; /* link to global list */
> u8 bus; /* PCI bus number */
> u8 devfn; /* PCI devfn number */
> + u16 pfsid; /* SRIOV physical function source ID */
> u8 pasid_supported:3;
> u8 pasid_enabled:1;
> u8 pri_supported:1;