[PATCH 1/1] iommu/vt-d: Report more information about invalidation errors

From: Lu Baolu
Date: Wed Mar 17 2021 - 21:03:52 EST


When the invalidation queue errors are encountered, dump the information
logged by the VT-d hardware together with the pending queue invalidation
descriptors.

Signed-off-by: Ashok Raj <ashok.raj@xxxxxxxxx>
Tested-by: Guo Kaijie <Kaijie.Guo@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel/dmar.c | 68 ++++++++++++++++++++++++++++++++++---
include/linux/intel-iommu.h | 6 ++++
2 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/intel/dmar.c b/drivers/iommu/intel/dmar.c
index d5c51b5c20af..6971397805f3 100644
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -1205,6 +1205,63 @@ static inline void reclaim_free_desc(struct q_inval *qi)
}
}

+static const char *qi_type_string(u8 type)
+{
+ switch (type) {
+ case QI_CC_TYPE:
+ return "Context-cache Invalidation";
+ case QI_IOTLB_TYPE:
+ return "IOTLB Invalidation";
+ case QI_DIOTLB_TYPE:
+ return "Device-TLB Invalidation";
+ case QI_IEC_TYPE:
+ return "Interrupt Entry Cache Invalidation";
+ case QI_IWD_TYPE:
+ return "Invalidation Wait";
+ case QI_EIOTLB_TYPE:
+ return "PASID-based IOTLB Invalidation";
+ case QI_PC_TYPE:
+ return "PASID-cache Invalidation";
+ case QI_DEIOTLB_TYPE:
+ return "PASID-based Device-TLB Invalidation";
+ case QI_PGRP_RESP_TYPE:
+ return "Page Group Response";
+ default:
+ return "UNKNOWN";
+ }
+}
+
+static void qi_dump_fault(struct intel_iommu *iommu, u32 fault)
+{
+ unsigned int head = dmar_readl(iommu->reg + DMAR_IQH_REG);
+ u64 iqe_err = dmar_readq(iommu->reg + DMAR_IQER_REG);
+ struct qi_desc *desc = iommu->qi->desc + head;
+
+ if (fault & DMA_FSTS_IQE)
+ pr_err("VT-d detected Invalidation Queue Error: Reason %llx",
+ DMAR_IQER_REG_IQEI(iqe_err));
+ if (fault & DMA_FSTS_ITE)
+ pr_err("VT-d detected Invalidation Time-out Error: SID %llx",
+ DMAR_IQER_REG_ITESID(iqe_err));
+ if (fault & DMA_FSTS_ICE)
+ pr_err("VT-d detected Invalidation Completion Error: SID %llx",
+ DMAR_IQER_REG_ICESID(iqe_err));
+
+ pr_err("QI HEAD: %s qw0 = 0x%llx, qw1 = 0x%llx\n",
+ qi_type_string(desc->qw0 & 0xf),
+ (unsigned long long)desc->qw0,
+ (unsigned long long)desc->qw1);
+
+ head = ((head >> qi_shift(iommu)) + QI_LENGTH - 1) % QI_LENGTH;
+ head <<= qi_shift(iommu);
+ desc = iommu->qi->desc + head;
+
+ pr_err("QI PRIOR: %s qw0 = 0x%llx, qw1 = 0x%llx\n",
+ qi_type_string(desc->qw0 & 0xf),
+ (unsigned long long)desc->qw0,
+ (unsigned long long)desc->qw1);
+}
+
static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index)
{
u32 fault;
@@ -1216,6 +1273,8 @@ static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index)
return -EAGAIN;

fault = readl(iommu->reg + DMAR_FSTS_REG);
+ if (fault & (DMA_FSTS_IQE | DMA_FSTS_ITE | DMA_FSTS_ICE))
+ qi_dump_fault(iommu, fault);

/*
* If IQE happens, the head points to the descriptor associated
@@ -1232,12 +1291,10 @@ static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index)
* used by software as private data. We won't print
* out these two qw's for security consideration.
*/
- pr_err("VT-d detected invalid descriptor: qw0 = %llx, qw1 = %llx\n",
- (unsigned long long)desc->qw0,
- (unsigned long long)desc->qw1);
memcpy(desc, qi->desc + (wait_index << shift),
1 << shift);
writel(DMA_FSTS_IQE, iommu->reg + DMAR_FSTS_REG);
+ pr_info("Invalidation Queue Error (IQE) cleared\n");
return -EINVAL;
}
}
@@ -1254,6 +1311,7 @@ static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index)
tail = ((tail >> shift) - 1 + QI_LENGTH) % QI_LENGTH;

writel(DMA_FSTS_ITE, iommu->reg + DMAR_FSTS_REG);
+ pr_info("Invalidation Time-out Error (ITE) cleared\n");

do {
if (qi->desc_status[head] == QI_IN_USE)
@@ -1265,8 +1323,10 @@ static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index)
return -EAGAIN;
}

- if (fault & DMA_FSTS_ICE)
+ if (fault & DMA_FSTS_ICE) {
writel(DMA_FSTS_ICE, iommu->reg + DMAR_FSTS_REG);
+ pr_info("Invalidation Completion Error (ICE) cleared\n");
+ }

return 0;
}
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index d1f32b33415a..76f974da8ca4 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -20,6 +20,7 @@
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/dmar.h>
#include <linux/ioasid.h>
+#include <linux/bitfield.h>

#include <asm/cacheflush.h>
#include <asm/iommu.h>
@@ -80,6 +81,7 @@
#define DMAR_IQ_SHIFT 4 /* Invalidation queue head/tail shift */
#define DMAR_IQA_REG 0x90 /* Invalidation queue addr register */
#define DMAR_ICS_REG 0x9c /* Invalidation complete status register */
+#define DMAR_IQER_REG 0xb0 /* Invalidation queue error record register */
#define DMAR_IRTA_REG 0xb8 /* Interrupt remapping table addr register */
#define DMAR_PQH_REG 0xc0 /* Page request queue head register */
#define DMAR_PQT_REG 0xc8 /* Page request queue tail register */
@@ -126,6 +128,10 @@
#define DMAR_VCMD_REG 0xe10 /* Virtual command register */
#define DMAR_VCRSP_REG 0xe20 /* Virtual command response register */

+#define DMAR_IQER_REG_IQEI(reg) FIELD_GET(GENMASK_ULL(3, 0), reg)
+#define DMAR_IQER_REG_ITESID(reg) FIELD_GET(GENMASK_ULL(47, 32), reg)
+#define DMAR_IQER_REG_ICESID(reg) FIELD_GET(GENMASK_ULL(63, 48), reg)
+
#define OFFSET_STRIDE (9)

#define dmar_readq(a) readq(a)
--
2.25.1