1 files changed, 31 insertions, 12 deletions

diff --git a/drivers/iommu/intel/debugfs.c b/drivers/iommu/intel/debugfs.c
index d927ef10641b..6e1a3f88abc8 100644
--- a/drivers/iommu/intel/debugfs.c
+++ b/drivers/iommu/intel/debugfs.c
@@ -342,13 +342,13 @@ static void pgtable_walk_level(struct seq_file *m, struct dma_pte *pde,
 	}
 }
 
-static int show_device_domain_translation(struct device *dev, void *data)
+static int __show_device_domain_translation(struct device *dev, void *data)
 {
-	struct device_domain_info *info = dev_iommu_priv_get(dev);
-	struct dmar_domain *domain = info->domain;
+	struct dmar_domain *domain;
 	struct seq_file *m = data;
 	u64 path[6] = { 0 };
 
+	domain = to_dmar_domain(iommu_get_domain_for_dev(dev));
 	if (!domain)
 		return 0;
 
@@ -359,20 +359,39 @@ static int show_device_domain_translation(struct device *dev, void *data)
 	pgtable_walk_level(m, domain->pgd, domain->agaw + 2, 0, path);
 	seq_putc(m, '\n');
 
-	return 0;
+	/* Don't iterate */
+	return 1;
 }
 
-static int domain_translation_struct_show(struct seq_file *m, void *unused)
+static int show_device_domain_translation(struct device *dev, void *data)
 {
-	unsigned long flags;
-	int ret;
+	struct iommu_group *group;
 
-	spin_lock_irqsave(&device_domain_lock, flags);
-	ret = bus_for_each_dev(&pci_bus_type, NULL, m,
-			       show_device_domain_translation);
-	spin_unlock_irqrestore(&device_domain_lock, flags);
+	group = iommu_group_get(dev);
+	if (group) {
+		/*
+		 * The group->mutex is held across the callback, which will
+		 * block calls to iommu_attach/detach_group/device. Hence,
+		 * the domain of the device will not change during traversal.
+		 *
+		 * All devices in an iommu group share a single domain, hence
+		 * we only dump the domain of the first device. Even though,
+		 * this code still possibly races with the iommu_unmap()
+		 * interface. This could be solved by RCU-freeing the page
+		 * table pages in the iommu_unmap() path.
+		 */
+		iommu_group_for_each_dev(group, data,
+					 __show_device_domain_translation);
+		iommu_group_put(group);
+	}
 
-	return ret;
+	return 0;
+}
+
+static int domain_translation_struct_show(struct seq_file *m, void *unused)
+{
+	return bus_for_each_dev(&pci_bus_type, NULL, m,
+				show_device_domain_translation);
 }
 DEFINE_SHOW_ATTRIBUTE(domain_translation_struct);