[PATCH 5/6] iommu/vt-d: Add debugfs extension to show Pasid table contents

From: Sohil Mehta
Date: Thu Oct 12 2017 - 20:04:28 EST


From: Gayatri Kammela <gayatri.kammela@xxxxxxxxx>

Debugfs extension to dump the internals such as pasid table entries for
each IOMMU to the userspace.

Example of such dump in Kabylake:

root@OTC-KBLH-01:~# cat /sys/kernel/debug/intel_iommu/intel_iommu_ctx

IOMMU dmar0: Extended Root Table Addr:4310c4800
Extended Root tbl entries:
Bus 0 L: 3ff5a8001 H: 0
Lower Context table entries for Bus: 0
[entry] DID :B :D .F Low High
[80] 0000:00:0a.00 3ff5a9a05 102
Higher Context tbl entries for Bus: 0
[80] 0000:00:0a.00 40160000c 725140000000
Pasid Table Addr : ffff8db2c1600000
Pasid table entries for domain: 0000
[Entry] Contents
[0] 26a609801

Cc: Sohil Mehta <sohil.mehta@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Cc: Ashok Raj <ashok.raj@xxxxxxxxx>
Signed-off-by: Gayatri Kammela <gayatri.kammela@xxxxxxxxx>
---
drivers/iommu/intel-iommu-debug.c | 33 +++++++++++++++++++++++++++++++++
drivers/iommu/intel-svm.c | 8 --------
include/linux/intel-svm.h | 8 ++++++++
3 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/intel-iommu-debug.c b/drivers/iommu/intel-iommu-debug.c
index 295cadc..2de4f1b 100644
--- a/drivers/iommu/intel-iommu-debug.c
+++ b/drivers/iommu/intel-iommu-debug.c
@@ -34,6 +34,32 @@
#define TOTAL_BUS_NR (256) /* full bus range 256 */

#ifdef CONFIG_INTEL_IOMMU_SVM
+static void pasid_tbl_entry_show(struct seq_file *m, void *unused,
+ struct intel_iommu *iommu)
+{
+ int pasid_size = 0, i;
+
+ if (ecap_pasid(iommu->ecap)) {
+ pasid_size = intel_iommu_get_pts(iommu);
+ seq_printf(m, "Pasid Table Addr : %llx\n", (unsigned long long)
+ iommu->pasid_table);
+
+ if (iommu->pasid_table) {
+ seq_printf(m, "Pasid table entries for domain %d:\n",
+ iommu->segment);
+ seq_printf(m, "%2s\t\t%4s\n", "[Entry]", "Contents");
+
+ /* Publish the pasid table entries here */
+ for (i = 0; i < pasid_size; i++) {
+ if (!iommu->pasid_table[i].val)
+ continue;
+ seq_printf(m, "[%d]\t%04llx\n", i,
+ iommu->pasid_table[i].val);
+ }
+ }
+ }
+}
+
static void ext_ctx_tbl_entry_show(struct seq_file *m, void *unused,
struct intel_iommu *iommu, int bus, int ctx,
struct context_entry *context, bool new_ext)
@@ -57,6 +83,12 @@ static void ext_ctx_tbl_entry_show(struct seq_file *m, void *unused,
}
}
#else /* CONFIG_INTEL_IOMMU_SVM */
+static void pasid_tbl_entry_show(struct seq_file *m, void *unused,
+ struct intel_iommu *iommu)
+{
+ return;
+}
+
static void ext_ctx_tbl_entry_show(struct seq_file *m, void *unused,
struct intel_iommu *iommu, int bus, int ctx,
struct context_entry *context, bool new_ext)
@@ -93,6 +125,7 @@ static void ctx_tbl_entry_show(struct seq_file *m, void *unused,
context, new_ext);
}
}
+ pasid_tbl_entry_show(m, unused, iommu);
out:
spin_unlock_irqrestore(&iommu->lock, flags);
}
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index f6697e5..2003f23 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -28,14 +28,6 @@

static irqreturn_t prq_event_thread(int irq, void *d);

-struct pasid_entry {
- u64 val;
-};
-
-struct pasid_state_entry {
- u64 val;
-};
-
int intel_svm_alloc_pasid_tables(struct intel_iommu *iommu)
{
struct page *pages;
diff --git a/include/linux/intel-svm.h b/include/linux/intel-svm.h
index 733eaf9..a8abad6 100644
--- a/include/linux/intel-svm.h
+++ b/include/linux/intel-svm.h
@@ -18,6 +18,14 @@

struct device;

+struct pasid_entry {
+ u64 val;
+};
+
+struct pasid_state_entry {
+ u64 val;
+};
+
struct svm_dev_ops {
void (*fault_cb)(struct device *dev, int pasid, u64 address,
u32 private, int rwxp, int response);
--
2.7.4