[PATCH 18/19] iommu/vt-d: Report SVA feature with generic flag

[Lu Baolu <baolu.lu@linux.intel.com>]

From: Jacob Pan <jacob.jun.pan@linux.intel.com>

Query Shared Virtual Address/Memory capability is a generic feature.
SVA feature check is the required first step before calling
iommu_sva_bind_device().

VT-d checks SVA feature enabling at per IOMMU level during this step,
SVA bind device will check and enable PCI ATS, PRS, and PASID capabilities
at device level.

This patch reports Intel SVM as SVA feature such that generic code
(e.g. Uacce [1]) can use it.

[1] https://lkml.org/lkml/2020/1/15/604

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/intel-iommu.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 3c82fcb50ee7..c79e68ae42a8 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5956,6 +5956,14 @@ intel_iommu_dev_has_feat(struct device *dev, enum iommu_dev_features feat)
 		return !!siov_find_pci_dvsec(to_pci_dev(dev));
 	}
 
+	if (feat == IOMMU_DEV_FEAT_SVA) {
+		struct device_domain_info *info = get_domain_info(dev);
+
+		return info && (info->iommu->flags & VTD_FLAG_SVM_CAPABLE) &&
+			info->pasid_supported && info->pri_supported &&
+			info->ats_supported;
+	}
+
 	return false;
 }
 
@@ -5965,6 +5973,16 @@ intel_iommu_dev_enable_feat(struct device *dev, enum iommu_dev_features feat)
 	if (feat == IOMMU_DEV_FEAT_AUX)
 		return intel_iommu_enable_auxd(dev);
 
+	if (feat == IOMMU_DEV_FEAT_SVA) {
+		struct device_domain_info *info = get_domain_info(dev);
+
+		if (!info)
+			return -EINVAL;
+
+		if (info->iommu->flags & VTD_FLAG_SVM_CAPABLE)
+			return 0;
+	}
+
 	return -ENODEV;
 }
 
-- 
2.17.1

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