From:   Lu Baolu <baolu.lu@linux.intel.com>
To:     iommu@lists.linux.dev, dmaengine@vger.kernel.org
Cc:     Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Kevin Tian <kevin.tian@intel.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Vinod Koul <vkoul@kernel.org>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        linux-kernel@vger.kernel.org, Lu Baolu <baolu.lu@linux.intel.com>
Subject: [PATCH v2 2/5] iommu/vt-d: Allow SVA with device-specific IOPF
Date:   Thu,  9 Mar 2023 10:56:36 +0800
Message-Id: <20230309025639.26109-3-baolu.lu@linux.intel.com>
In-Reply-To: <20230309025639.26109-1-baolu.lu@linux.intel.com>
References: <20230309025639.26109-1-baolu.lu@linux.intel.com>
MIME-Version: 1.0
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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