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From:   Jacob Pan <jacob.jun.pan@linux.intel.com>
To:     iommu@lists.linux-foundation.org,
        LKML <linux-kernel@vger.kernel.org>,
        "Lu Baolu" <baolu.lu@linux.intel.com>,
        Joerg Roedel <joro@8bytes.org>,
        David Woodhouse <dwmw2@infradead.org>
Cc:     "Yi Liu" <yi.l.liu@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>,
        Raj Ashok <ashok.raj@intel.com>,
        Jean-Philippe Brucker <jean-philippe@linaro.com>,
        Eric Auger <eric.auger@redhat.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH 1/2] iommu/vt-d: Report SVA feature with generic flag
Date:   Mon, 24 Feb 2020 15:26:36 -0800
Message-Id: <1582586797-61697-3-git-send-email-jacob.jun.pan@linux.intel.com>
In-Reply-To: <1582586797-61697-1-git-send-email-jacob.jun.pan@linux.intel.com>
References: <1582586797-61697-1-git-send-email-jacob.jun.pan@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
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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>
---
 drivers/iommu/intel-iommu.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 92c2f2e4197b..5eca6e10d2a4 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -6346,9 +6346,14 @@ intel_iommu_dev_has_feat(struct device *dev, enum iommu_dev_features feat)
 static int
 intel_iommu_dev_enable_feat(struct device *dev, enum iommu_dev_features feat)
 {
+	struct intel_iommu *intel_iommu = dev_to_intel_iommu(dev);
+
 	if (feat == IOMMU_DEV_FEAT_AUX)
 		return intel_iommu_enable_auxd(dev);
 
+	if (feat == IOMMU_DEV_FEAT_SVA)
+		return intel_iommu->flags & VTD_FLAG_SVM_CAPABLE;
+
 	return -ENODEV;
 }
 
-- 
2.7.4