On 3/21/23 12:00 AM, Jacob Pan wrote:
Hi BaoLu,
Hi Jacob,
On Thu, 9 Mar 2023 10:56:36 +0800, Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>
wrote:
Currently enabling SVA requires IOPF support from the IOMMU and device
PCI PRI. However, some devices can handle IOPF by itself without ever
sending PCI page requests nor advertising PRI capability.
Allow SVA support with IOPF handled either by IOMMU (PCI PRI) or device
driver (device-specific IOPF). As long as IOPF could be handled, SVA
should continue to work.
Signed-off-by: Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel/iommu.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 7c2f4bd33582..d2fcab9d8f61 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4650,7 +4650,18 @@ static int intel_iommu_enable_sva(struct device
*dev) if (!(iommu->flags & VTD_FLAG_SVM_CAPABLE))
return -ENODEV;
- if (!info->pasid_enabled || !info->pri_enabled ||
!info->ats_enabled)
+ if (!info->pasid_enabled)
+ return -EINVAL;
+
+ /*
+ * Devices having device-specific I/O fault handling should not
+ * support PCI/PRI.
+ */
+ if (!info->pri_supported)
+ return 0;
If you put this check at the very beginning, everything else should it be
the same, right?
Even for device specific IOPF, PASID/ATS are still required on the IOMMU
side.
Still feel a little weird that, SVA is tied to PRI for PCI PRI but not for
device specific IOPF.
PCI PRI and device specific IOPF *should* be equivalent. But the IOMMU
side has no means to check the capability of device-specific IOPF.
Therefore, IOMMU can only default that if the device driver enables SVA
on a non-PRI device, it will handle IOPF in its own way.
Best regards,
baolu
