3 files changed, 125 insertions, 2 deletions

diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
index 0ddb77115be7..247d0f2d5fdf 100644
--- a/drivers/iommu/intel/Kconfig
+++ b/drivers/iommu/intel/Kconfig
@@ -6,6 +6,9 @@ config DMAR_TABLE
 config DMAR_PERF
 	bool
 
+config DMAR_DEBUG
+	bool
+
 config INTEL_IOMMU
 	bool "Support for Intel IOMMU using DMA Remapping Devices"
 	depends on PCI_MSI && ACPI && (X86 || IA64)
@@ -31,6 +34,7 @@ config INTEL_IOMMU_DEBUGFS
 	bool "Export Intel IOMMU internals in Debugfs"
 	depends on IOMMU_DEBUGFS
 	select DMAR_PERF
+	select DMAR_DEBUG
 	help
 	  !!!WARNING!!!
 
diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index b7708b93f3fa..915bff76fe96 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -1941,12 +1941,16 @@ static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
 
 	reason = dmar_get_fault_reason(fault_reason, &fault_type);
 
-	if (fault_type == INTR_REMAP)
+	if (fault_type == INTR_REMAP) {
 		pr_err("[INTR-REMAP] Request device [%02x:%02x.%d] fault index 0x%llx [fault reason 0x%02x] %s\n",
 		       source_id >> 8, PCI_SLOT(source_id & 0xFF),
 		       PCI_FUNC(source_id & 0xFF), addr >> 48,
 		       fault_reason, reason);
-	else if (pasid == INVALID_IOASID)
+
+		return 0;
+	}
+
+	if (pasid == INVALID_IOASID)
 		pr_err("[%s NO_PASID] Request device [%02x:%02x.%d] fault addr 0x%llx [fault reason 0x%02x] %s\n",
 		       type ? "DMA Read" : "DMA Write",
 		       source_id >> 8, PCI_SLOT(source_id & 0xFF),
@@ -1959,6 +1963,8 @@ static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
 		       PCI_FUNC(source_id & 0xFF), addr,
 		       fault_reason, reason);
 
+	dmar_fault_dump_ptes(iommu, source_id, addr, pasid);
+
 	return 0;
 }
 
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 9a356075d345..abb2599998b1 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -156,6 +156,8 @@ static struct intel_iommu **g_iommus;
 
 static void __init check_tylersburg_isoch(void);
 static int rwbf_quirk;
+static inline struct device_domain_info *
+dmar_search_domain_by_dev_info(int segment, int bus, int devfn);
 
 /*
  * set to 1 to panic kernel if can't successfully enable VT-d
@@ -996,6 +998,117 @@ out:
 	spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
+#ifdef CONFIG_DMAR_DEBUG
+static void pgtable_walk(struct intel_iommu *iommu, unsigned long pfn, u8 bus, u8 devfn)
+{
+	struct device_domain_info *info;
+	struct dma_pte *parent, *pte;
+	struct dmar_domain *domain;
+	int offset, level;
+
+	info = dmar_search_domain_by_dev_info(iommu->segment, bus, devfn);
+	if (!info || !info->domain) {
+		pr_info("device [%02x:%02x.%d] not probed\n",
+			bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
+		return;
+	}
+
+	domain = info->domain;
+	level = agaw_to_level(domain->agaw);
+	parent = domain->pgd;
+	if (!parent) {
+		pr_info("no page table setup\n");
+		return;
+	}
+
+	while (1) {
+		offset = pfn_level_offset(pfn, level);
+		pte = &parent[offset];
+		if (!pte || (dma_pte_superpage(pte) || !dma_pte_present(pte))) {
+			pr_info("PTE not present at level %d\n", level);
+			break;
+		}
+
+		pr_info("pte level: %d, pte value: 0x%016llx\n", level, pte->val);
+
+		if (level == 1)
+			break;
+
+		parent = phys_to_virt(dma_pte_addr(pte));
+		level--;
+	}
+}
+
+void dmar_fault_dump_ptes(struct intel_iommu *iommu, u16 source_id,
+			  unsigned long long addr, u32 pasid)
+{
+	struct pasid_dir_entry *dir, *pde;
+	struct pasid_entry *entries, *pte;
+	struct context_entry *ctx_entry;
+	struct root_entry *rt_entry;
+	u8 devfn = source_id & 0xff;
+	u8 bus = source_id >> 8;
+	int i, dir_index, index;
+
+	pr_info("Dump %s table entries for IOVA 0x%llx\n", iommu->name, addr);
+
+	/* root entry dump */
+	rt_entry = &iommu->root_entry[bus];
+	if (!rt_entry) {
+		pr_info("root table entry is not present\n");
+		return;
+	}
+
+	if (sm_supported(iommu))
+		pr_info("scalable mode root entry: hi 0x%016llx, low 0x%016llx\n",
+			rt_entry->hi, rt_entry->lo);
+	else
+		pr_info("root entry: 0x%016llx", rt_entry->lo);
+
+	/* context entry dump */
+	ctx_entry = iommu_context_addr(iommu, bus, devfn, 0);
+	if (!ctx_entry) {
+		pr_info("context table entry is not present\n");
+		return;
+	}
+
+	pr_info("context entry: hi 0x%016llx, low 0x%016llx\n",
+		ctx_entry->hi, ctx_entry->lo);
+
+	/* legacy mode does not require PASID entries */
+	if (!sm_supported(iommu))
+		goto pgtable_walk;
+
+	/* get the pointer to pasid directory entry */
+	dir = phys_to_virt(ctx_entry->lo & VTD_PAGE_MASK);
+	if (!dir) {
+		pr_info("pasid directory entry is not present\n");
+		return;
+	}
+	/* For request-without-pasid, get the pasid from context entry */
+	if (intel_iommu_sm && pasid == INVALID_IOASID)
+		pasid = PASID_RID2PASID;
+
+	dir_index = pasid >> PASID_PDE_SHIFT;
+	pde = &dir[dir_index];
+	pr_info("pasid dir entry: 0x%016llx\n", pde->val);
+
+	/* get the pointer to the pasid table entry */
+	entries = get_pasid_table_from_pde(pde);
+	if (!entries) {
+		pr_info("pasid table entry is not present\n");
+		return;
+	}
+	index = pasid & PASID_PTE_MASK;
+	pte = &entries[index];
+	for (i = 0; i < ARRAY_SIZE(pte->val); i++)
+		pr_info("pasid table entry[%d]: 0x%016llx\n", i, pte->val[i]);
+
+pgtable_walk:
+	pgtable_walk(iommu, addr >> VTD_PAGE_SHIFT, bus, devfn);
+}
+#endif
+
 static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
 				      unsigned long pfn, int *target_level)
 {