[PATCH v2 2/5] iommu/vt-d: Allow SVA with device-specific IOPF

Lu Baolu
2023-03-09T02:57:55Z

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@linux.intel.com>
---
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;
+
+ /* Devices supporting ATS/PRI should have it enabled. */
+ if (!info->pri_enabled || !info->ats_enabled)
return -EINVAL;

ret = iopf_queue_add_device(iommu->iopf_queue, dev);
--
2.34.1