[PATCH v4 06/15] iommu/vt-d: Support setting ioasid set to domain

[Liu Yi L]

>From IOMMU p.o.v., PASIDs allocated and managed by external components
(e.g. VFIO) will be passed in for gpasid_bind/unbind operation. IOMMU
needs some knowledge to check the PASID ownership, hence add an interface
for those components to tell the PASID owner.

In latest kernel design, PASID ownership is managed by IOASID set where
the PASID is allocated from. This patch adds support for setting ioasid
set ID to the domains used for nesting/vSVA. Subsequent SVA operations
on the PASID will be checked against its IOASID set for proper ownership.

Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
CC: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
Cc: Eric Auger <eric.auger@xxxxxxxxxx>
Cc: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Liu Yi L <yi.l.liu@xxxxxxxxx>
Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
---
 drivers/iommu/intel/iommu.c | 16 ++++++++++++++++
 include/linux/intel-iommu.h |  4 ++++
 include/linux/iommu.h       |  1 +
 3 files changed, 21 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 62ebe01..89d708d 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1793,6 +1793,7 @@ static struct dmar_domain *alloc_domain(int flags)
 	if (first_level_by_default())
 		domain->flags |= DOMAIN_FLAG_USE_FIRST_LEVEL;
 	domain->has_iotlb_device = false;
+	domain->ioasid_sid = INVALID_IOASID_SET;
 	INIT_LIST_HEAD(&domain->devices);
 
 	return domain;
@@ -6039,6 +6040,21 @@ intel_iommu_domain_set_attr(struct iommu_domain *domain,
 		}
 		spin_unlock_irqrestore(&device_domain_lock, flags);
 		break;
+	case DOMAIN_ATTR_IOASID_SID:
+		if (!(dmar_domain->flags & DOMAIN_FLAG_NESTING_MODE)) {
+			ret = -ENODEV;
+			break;
+		}
+		if ((dmar_domain->ioasid_sid != INVALID_IOASID_SET) &&
+		    (dmar_domain->ioasid_sid != (*(int *) data))) {
+			pr_warn_ratelimited("multi ioasid_set (%d:%d) setting",
+					    dmar_domain->ioasid_sid,
+					    (*(int *) data));
+			ret = -EBUSY;
+			break;
+		}
+		dmar_domain->ioasid_sid = *(int *) data;
+		break;
 	default:
 		ret = -EINVAL;
 		break;
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 3f23c26..0d0ab32 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -549,6 +549,10 @@ struct dmar_domain {
 					   2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
 	u64		max_addr;	/* maximum mapped address */
 
+	int		ioasid_sid;	/*
+					 * the ioasid set which tracks all
+					 * PASIDs used by the domain.
+					 */
 	int		default_pasid;	/*
 					 * The default pasid used for non-SVM
 					 * traffic on mediated devices.
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 2567c33..21d32be 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -124,6 +124,7 @@ enum iommu_attr {
 	DOMAIN_ATTR_FSL_PAMUV1,
 	DOMAIN_ATTR_NESTING,	/* two stages of translation */
 	DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
+	DOMAIN_ATTR_IOASID_SID,
 	DOMAIN_ATTR_MAX,
 };
 
-- 
2.7.4