linux-kernel - [PATCH v2 3/3] iommu/vt-d: Fix ineffective devTLB invalidation for subdevices

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Message-Id: <20201223062720.29364-4-yi.l.liu@intel.com>
Date:   Wed, 23 Dec 2020 14:27:20 +0800
From:   Liu Yi L <yi.l.liu@...el.com>
To:     baolu.lu@...ux.intel.com, joro@...tes.org, will@...nel.org,
        jacob.jun.pan@...ux.intel.com
Cc:     kevin.tian@...el.com, ashok.raj@...el.com, yi.l.liu@...el.com,
        jun.j.tian@...el.com, yi.y.sun@...el.com,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 3/3] iommu/vt-d: Fix ineffective devTLB invalidation for subdevices

iommu_flush_dev_iotlb() is called to invalidate caches on device. It only
loops the devices which are full-attached to the domain. For sub-devices,
this is ineffective. This results in invalid caching entries left on the
device. Fix it by adding loop for subdevices as well. Also, the domain->
has_iotlb_device needs to be updated when attaching to subdevices.

Fixes: 67b8e02b5e761 ("iommu/vt-d: Aux-domain specific domain attach/detach")
Signed-off-by: Liu Yi L <yi.l.liu@...el.com>
---
 drivers/iommu/intel/iommu.c | 63 +++++++++++++++++++++++++++----------
 1 file changed, 47 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index acfe0a5b955e..e97c5ac1d7fc 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -726,6 +726,8 @@ static int domain_update_device_node(struct dmar_domain *domain)
 	return nid;
 }
 
+static void domain_update_iotlb(struct dmar_domain *domain);
+
 /* Some capabilities may be different across iommus */
 static void domain_update_iommu_cap(struct dmar_domain *domain)
 {
@@ -739,6 +741,8 @@ static void domain_update_iommu_cap(struct dmar_domain *domain)
 	 */
 	if (domain->nid == NUMA_NO_NODE)
 		domain->nid = domain_update_device_node(domain);
+
+	domain_update_iotlb(domain);
 }
 
 struct context_entry *iommu_context_addr(struct intel_iommu *iommu, u8 bus,
@@ -1459,6 +1463,18 @@ iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu,
 	return NULL;
 }
 
+static bool dev_iotlb_enabled(struct device_domain_info *info)
+{
+	struct pci_dev *pdev;
+
+	if (!info->dev || !dev_is_pci(info->dev))
+		return false;
+
+	pdev = to_pci_dev(info->dev);
+
+	return !!pdev->ats_enabled;
+}
+
 static void domain_update_iotlb(struct dmar_domain *domain)
 {
 	struct device_domain_info *info;
@@ -1466,17 +1482,20 @@ static void domain_update_iotlb(struct dmar_domain *domain)
 
 	assert_spin_locked(&device_domain_lock);
 
-	list_for_each_entry(info, &domain->devices, link) {
-		struct pci_dev *pdev;
-
-		if (!info->dev || !dev_is_pci(info->dev))
-			continue;
-
-		pdev = to_pci_dev(info->dev);
-		if (pdev->ats_enabled) {
+	list_for_each_entry(info, &domain->devices, link)
+		if (dev_iotlb_enabled(info)) {
 			has_iotlb_device = true;
 			break;
 		}
+
+	if (!has_iotlb_device) {
+		struct subdev_domain_info *sinfo;
+
+		list_for_each_entry(sinfo, &domain->subdevices, link_domain)
+			if (dev_iotlb_enabled(get_domain_info(sinfo->pdev))) {
+				has_iotlb_device = true;
+				break;
+			}
 	}
 
 	domain->has_iotlb_device = has_iotlb_device;
@@ -1557,25 +1576,37 @@ static void iommu_disable_dev_iotlb(struct device_domain_info *info)
 #endif
 }
 
+static void __iommu_flush_dev_iotlb(struct device_domain_info *info,
+				    u64 addr, unsigned int mask)
+{
+	u16 sid, qdep;
+
+	if (!info || !info->ats_enabled)
+		return;
+
+	sid = info->bus << 8 | info->devfn;
+	qdep = info->ats_qdep;
+	qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
+			   qdep, addr, mask);
+}
+
 static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
 				  u64 addr, unsigned mask)
 {
-	u16 sid, qdep;
 	unsigned long flags;
 	struct device_domain_info *info;
+	struct subdev_domain_info *sinfo;
 
 	if (!domain->has_iotlb_device)
 		return;
 
 	spin_lock_irqsave(&device_domain_lock, flags);
-	list_for_each_entry(info, &domain->devices, link) {
-		if (!info->ats_enabled)
-			continue;
+	list_for_each_entry(info, &domain->devices, link)
+		__iommu_flush_dev_iotlb(info, addr, mask);
 
-		sid = info->bus << 8 | info->devfn;
-		qdep = info->ats_qdep;
-		qi_flush_dev_iotlb(info->iommu, sid, info->pfsid,
-				qdep, addr, mask);
+	list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
+		__iommu_flush_dev_iotlb(get_domain_info(sinfo->pdev),
+					addr, mask);
 	}
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 }
-- 
2.25.1