[PATCH] iommu/vt-d: Add Scalable Mode fault information

From: Kyung Min Park
Date: Fri Sep 06 2019 - 14:20:27 EST


Intel VT-d specification revision 3 added support for Scalable Mode
Translation for DMA remapping. Add the Scalable Mode fault reasons to
show detailed fault reasons when the translation fault happens.

Link: https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf

Reviewed-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>
Signed-off-by: Kyung Min Park <kyung.min.park@xxxxxxxxx>
---
drivers/iommu/dmar.c | 77 ++++++++++++++++++++++++++++++++++++++++++---
include/linux/intel-iommu.h | 2 ++
2 files changed, 75 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 1207e05..5cb63c5 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -1532,6 +1532,64 @@ static const char *dma_remap_fault_reasons[] =
"PCE for translation request specifies blocking",
};

+static const char * const dma_remap_sm_fault_reasons[] = {
+ "SM: Invalid Root Table Address",
+ "SM: TTM 0 for request with PASID",
+ "SM: TTM 0 for page group request",
+ "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x33-0x37 */
+ "SM: Error attempting to access Root Entry",
+ "SM: Present bit in Root Entry is clear",
+ "SM: Non-zero reserved field set in Root Entry",
+ "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x3B-0x3F */
+ "SM: Error attempting to access Context Entry",
+ "SM: Present bit in Context Entry is clear",
+ "SM: Non-zero reserved field set in the Context Entry",
+ "SM: Invalid Context Entry",
+ "SM: DTE field in Context Entry is clear",
+ "SM: PASID Enable field in Context Entry is clear",
+ "SM: PASID is larger than the max in Context Entry",
+ "SM: PRE field in Context-Entry is clear",
+ "SM: RID_PASID field error in Context-Entry",
+ "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x49-0x4F */
+ "SM: Error attempting to access the PASID Directory Entry",
+ "SM: Present bit in Directory Entry is clear",
+ "SM: Non-zero reserved field set in PASID Directory Entry",
+ "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x53-0x57 */
+ "SM: Error attempting to access PASID Table Entry",
+ "SM: Present bit in PASID Table Entry is clear",
+ "SM: Non-zero reserved field set in PASID Table Entry",
+ "SM: Invalid Scalable-Mode PASID Table Entry",
+ "SM: ERE field is clear in PASID Table Entry",
+ "SM: SRE field is clear in PASID Table Entry",
+ "Unknown", "Unknown",/* 0x5E-0x5F */
+ "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x60-0x67 */
+ "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x68-0x6F */
+ "SM: Error attempting to access first-level paging entry",
+ "SM: Present bit in first-level paging entry is clear",
+ "SM: Non-zero reserved field set in first-level paging entry",
+ "SM: Error attempting to access FL-PML4 entry",
+ "SM: First-level entry address beyond MGAW in Nested translation",
+ "SM: Read permission error in FL-PML4 entry in Nested translation",
+ "SM: Read permission error in first-level paging entry in Nested translation",
+ "SM: Write permission error in first-level paging entry in Nested translation",
+ "SM: Error attempting to access second-level paging entry",
+ "SM: Read/Write permission error in second-level paging entry",
+ "SM: Non-zero reserved field set in second-level paging entry",
+ "SM: Invalid second-level page table pointer",
+ "SM: A/D bit update needed in second-level entry when set up in no snoop",
+ "Unknown", "Unknown", "Unknown", /* 0x7D-0x7F */
+ "SM: Address in first-level translation is not canonical",
+ "SM: U/S set 0 for first-level translation with user privilege",
+ "SM: No execute permission for request with PASID and ER=1",
+ "SM: Address beyond the DMA hardware max",
+ "SM: Second-level entry address beyond the max",
+ "SM: No write permission for Write/AtomicOp request",
+ "SM: No read permission for Read/AtomicOp request",
+ "SM: Invalid address-interrupt address",
+ "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x88-0x8F */
+ "SM: A/D bit update needed in first-level entry when set up in no snoop",
+};
+
static const char *irq_remap_fault_reasons[] =
{
"Detected reserved fields in the decoded interrupt-remapped request",
@@ -1549,6 +1607,10 @@ static const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
ARRAY_SIZE(irq_remap_fault_reasons))) {
*fault_type = INTR_REMAP;
return irq_remap_fault_reasons[fault_reason - 0x20];
+ } else if (fault_reason >= 0x30 && (fault_reason - 0x30 <
+ ARRAY_SIZE(dma_remap_sm_fault_reasons))) {
+ *fault_type = DMA_REMAP;
+ return dma_remap_sm_fault_reasons[fault_reason - 0x30];
} else if (fault_reason < ARRAY_SIZE(dma_remap_fault_reasons)) {
*fault_type = DMA_REMAP;
return dma_remap_fault_reasons[fault_reason];
@@ -1624,7 +1686,8 @@ void dmar_msi_read(int irq, struct msi_msg *msg)
}

static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
- u8 fault_reason, u16 source_id, unsigned long long addr)
+ u8 fault_reason, int pasid, u16 source_id,
+ unsigned long long addr)
{
const char *reason;
int fault_type;
@@ -1637,10 +1700,11 @@ static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
PCI_FUNC(source_id & 0xFF), addr >> 48,
fault_reason, reason);
else
- pr_err("[%s] Request device [%02x:%02x.%d] fault addr %llx [fault reason %02d] %s\n",
+ pr_err("[%s] Request device [%02x:%02x.%d] PASID %x fault addr %llx [fault reason %02d] %s\n",
type ? "DMA Read" : "DMA Write",
source_id >> 8, PCI_SLOT(source_id & 0xFF),
- PCI_FUNC(source_id & 0xFF), addr, fault_reason, reason);
+ PCI_FUNC(source_id & 0xFF), pasid, addr,
+ fault_reason, reason);
return 0;
}

@@ -1672,8 +1736,9 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
u8 fault_reason;
u16 source_id;
u64 guest_addr;
- int type;
+ int type, pasid;
u32 data;
+ bool pasid_present;

/* highest 32 bits */
data = readl(iommu->reg + reg +
@@ -1685,10 +1750,12 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
fault_reason = dma_frcd_fault_reason(data);
type = dma_frcd_type(data);

+ pasid = dma_frcd_pasid_value(data);
data = readl(iommu->reg + reg +
fault_index * PRIMARY_FAULT_REG_LEN + 8);
source_id = dma_frcd_source_id(data);

+ pasid_present = dma_frcd_pasid_present(data);
guest_addr = dmar_readq(iommu->reg + reg +
fault_index * PRIMARY_FAULT_REG_LEN);
guest_addr = dma_frcd_page_addr(guest_addr);
@@ -1701,7 +1768,9 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
raw_spin_unlock_irqrestore(&iommu->register_lock, flag);

if (!ratelimited)
+ /* Using pasid -1 if pasid is not present */
dmar_fault_do_one(iommu, type, fault_reason,
+ pasid_present ? pasid : -1,
source_id, guest_addr);

fault_index++;
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 3c6327b..617f68f 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -265,6 +265,8 @@
#define dma_frcd_type(d) ((d >> 30) & 1)
#define dma_frcd_fault_reason(c) (c & 0xff)
#define dma_frcd_source_id(c) (c & 0xffff)
+#define dma_frcd_pasid_value(c) (((c) >> 8) & 0xfffff)
+#define dma_frcd_pasid_present(c) (((c) >> 31) & 1)
/* low 64 bit */
#define dma_frcd_page_addr(d) (d & (((u64)-1) << PAGE_SHIFT))

--
2.7.4