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From: Eric Auger <eric.auger@redhat.com>
To: eric.auger.pro@gmail.com, eric.auger@redhat.com,
	iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
	joro@8bytes.org, alex.williamson@redhat.com,
	jacob.jun.pan@linux.intel.com, yi.l.liu@intel.com,
	jean-philippe.brucker@arm.com, will.deacon@arm.com,
	robin.murphy@arm.com
Cc: kevin.tian@intel.com, ashok.raj@intel.com, marc.zyngier@arm.com,
	peter.maydell@linaro.org, vincent.stehle@arm.com,
	zhangfei.gao@gmail.com
Subject: [PATCH v9 11/14] iommu/smmuv3: Nested mode single MSI doorbell per domain enforcement
Date: Thu, 11 Jul 2019 13:49:56 +0200	[thread overview]
Message-ID: <20190711114959.15675-12-eric.auger@redhat.com> (raw)
In-Reply-To: <20190711114959.15675-1-eric.auger@redhat.com>

In nested mode we enforce the rule that all devices belonging
to the same iommu_domain share the same msi_domain.

Indeed if there were several physical MSI doorbells being used
within a single iommu_domain, it becomes really difficult to
resolve the nested stage mapping translating into the correct
physical doorbell. So let's forbid this situation.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
---
 drivers/iommu/arm-smmu-v3.c | 41 +++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 9b4654e2f25c..d0f66807674e 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2059,6 +2059,37 @@ static void arm_smmu_detach_dev(struct arm_smmu_master *master)
 	arm_smmu_disable_ats(master);
 }
 
+static bool arm_smmu_share_msi_domain(struct iommu_domain *domain,
+				      struct device *dev)
+{
+	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+	struct irq_domain *irqd = dev_get_msi_domain(dev);
+	struct arm_smmu_master *master;
+	unsigned long flags;
+	bool share = false;
+
+	if (!irqd)
+		return true;
+
+	spin_lock_irqsave(&smmu_domain->devices_lock, flags);
+	list_for_each_entry(master, &smmu_domain->devices, domain_head) {
+		struct irq_domain *d = dev_get_msi_domain(master->dev);
+
+		if (!d)
+			continue;
+		if (irqd != d) {
+			dev_info(dev, "Nested mode forbids to attach devices "
+				 "using different physical MSI doorbells "
+				 "to the same iommu_domain");
+			goto unlock;
+		}
+	}
+	share = true;
+unlock:
+	spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
+	return share;
+}
+
 static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 {
 	int ret = 0;
@@ -2093,6 +2124,16 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		ret = -ENXIO;
 		goto out_unlock;
 	}
+	/*
+	 * In nested mode we must check all devices belonging to the
+	 * domain share the same physical MSI doorbell. Otherwise nested
+	 * stage MSI binding is not supported.
+	 */
+	if (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED &&
+		!arm_smmu_share_msi_domain(domain, dev)) {
+		ret = -EINVAL;
+		goto out_unlock;
+	}
 
 	master->domain = smmu_domain;
 
-- 
2.20.1


  parent reply	other threads:[~2019-07-11 11:51 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-11 11:49 [PATCH v9 00/14] SMMUv3 Nested Stage Setup (IOMMU part) Eric Auger
2019-07-11 11:49 ` [PATCH v9 01/14] iommu: Introduce attach/detach_pasid_table API Eric Auger
2019-07-11 11:49 ` [PATCH v9 02/14] iommu: Introduce cache_invalidate API Eric Auger
2019-07-11 11:49 ` [PATCH v9 03/14] iommu: Introduce bind/unbind_guest_msi Eric Auger
2019-07-11 11:49 ` [PATCH v9 04/14] iommu/arm-smmu-v3: Maintain a SID->device structure Eric Auger
2019-07-11 11:49 ` [PATCH v9 05/14] iommu/smmuv3: Dynamically allocate s1_cfg and s2_cfg Eric Auger
2019-07-11 11:49 ` [PATCH v9 06/14] iommu/smmuv3: Get prepared for nested stage support Eric Auger
2019-07-11 11:49 ` [PATCH v9 07/14] iommu/smmuv3: Implement attach/detach_pasid_table Eric Auger
2019-07-11 11:49 ` [PATCH v9 08/14] iommu/smmuv3: Introduce __arm_smmu_tlb_inv_asid/s1_range_nosync Eric Auger
2019-07-11 11:49 ` [PATCH v9 09/14] iommu/smmuv3: Implement cache_invalidate Eric Auger
2019-07-11 11:49 ` [PATCH v9 10/14] dma-iommu: Implement NESTED_MSI cookie Eric Auger
2019-07-11 11:49 ` Eric Auger [this message]
2019-07-11 11:49 ` [PATCH v9 12/14] iommu/smmuv3: Enforce incompatibility between nested mode and HW MSI regions Eric Auger
2019-07-11 11:49 ` [PATCH v9 13/14] iommu/smmuv3: Implement bind/unbind_guest_msi Eric Auger
2019-07-11 11:49 ` [PATCH v9 14/14] iommu/smmuv3: Report non recoverable faults Eric Auger

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