[PATCH v2 1/1] iommu/vt-d: Tweak the description of a DMA fault

Lu Baolu
2021-05-17T06:55:31Z

The Intel IOMMU driver reports the DMA fault reason in a decimal number
while the VT-d specification uses a hexadecimal one. It's inconvenient
that users need to covert them everytime before consulting the spec.
Let's use hexadecimal number for a DMA fault reason.

The fault message uses 0xffffffff as PASID for DMA requests w/o PASID.
This is confusing. Tweak this by adding "NO_PASID" explicitly.

Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel/dmar.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)

Change log:
v1->v2:
- Add "0x" prefix to all hex numbers

diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index 1757ac1e1623..1e31e6799d5c 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -1911,16 +1911,23 @@ 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)
- pr_err("[INTR-REMAP] Request device [%02x:%02x.%d] fault index %llx [fault reason %02d] %s\n",
- source_id >> 8, PCI_SLOT(source_id & 0xFF),
- PCI_FUNC(source_id & 0xFF), addr >> 48,
- fault_reason, reason);
- else
- pr_err("[%s] Request device [%02x:%02x.%d] PASID %x fault addr %llx [fault reason %02d] %s\n",
+ pr_err("[INTR-REMAP] Request device [0x%02x:0x%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)
+ pr_err("[%s NO_PASID] Request device [0x%02x:0x%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),
- PCI_FUNC(source_id & 0xFF), pasid, addr,
+ PCI_FUNC(source_id & 0xFF), addr,
fault_reason, reason);
+ else
+ pr_err("[%s PASID 0x%x] Request device [0x%02x:0x%02x.%d] fault addr 0x%llx [fault reason 0x%02x] %s\n",
+ type ? "DMA Read" : "DMA Write", pasid,
+ source_id >> 8, PCI_SLOT(source_id & 0xFF),
+ PCI_FUNC(source_id & 0xFF), addr,
+ fault_reason, reason);
+
return 0;
}

@@ -1987,7 +1994,7 @@ irqreturn_t dmar_fault(int irq, void *dev_id)
if (!ratelimited)
/* Using pasid -1 if pasid is not present */
dmar_fault_do_one(iommu, type, fault_reason,
- pasid_present ? pasid : -1,
+ pasid_present ? pasid : INVALID_IOASID,
source_id, guest_addr);

fault_index++;
--
2.25.1