[PATCH v7 5/5] iommu/vt-d: Add debugfs support for Interrupt remapping

[Sohil Mehta]

Debugfs extension for Intel IOMMU to dump Interrupt remapping table
entries for Interrupt remapping and Interrupt posting.

The file /sys/kernel/debug/intel_iommu/ir_translation_struct provides
detailed information, such as Index, Source Id, Destination Id, Vector
and the IRTE values for entries with the present bit set, in the format
shown.

Remapped Interrupt supported on IOMMU: dmar7
 IR table address:85e50
 Index  SrcID DstIDVct IRTE_highIRTE_low
 1  f0f8  0100 30  0004f0f8 013d
 7  f0f8  0400 22  0004f0f8 0422000d

Posted Interrupt supported on IOMMU: dmar5
 IR table address:85ec0
 Index  SrcID PDA_high PDA_low  Vct IRTE_high   IRTE_low
 4  4300  000f ff765980 41  000f00044300ff76598000418001
 5  4300  000f ff765980 51  000f00044300ff76598000518001

Cc: Jacob Pan 
Cc: Fenghua Yu 
Cc: Ashok Raj 
Co-Developed-by: Gayatri Kammela 
Signed-off-by: Gayatri Kammela 
Signed-off-by: Sohil Mehta 
---

v7: Print the IR table physical base address
Simplify IR table formatting

v6: Change a couple of seq_puts to seq_putc

v5: Fix seq_puts formatting and remove leading '\n's

v4: Remove the unused function parameter
Fix checkpatch.pl warnings
Remove error reporting for debugfs_create_file function
Remove redundant IOMMU null check under for_each_active_iommu

v3: Use a macro for seq file operations 
Change the intel_iommu_interrupt_remap file name to ir_translation_struct

v2: Handle the case when IR is not enabled. Fix seq_printf formatting

 drivers/iommu/intel-iommu-debug.c | 94 +++
 1 file changed, 94 insertions(+)

diff --git a/drivers/iommu/intel-iommu-debug.c 
b/drivers/iommu/intel-iommu-debug.c
index a9a99aa..b66a073 100644
--- a/drivers/iommu/intel-iommu-debug.c
+++ b/drivers/iommu/intel-iommu-debug.c
@@ -229,6 +229,96 @@ static int iommu_regset_show(struct seq_file *m, void 
*unused)
 }
 DEFINE_SHOW_ATTRIBUTE(iommu_regset);
 
+#ifdef CONFIG_IRQ_REMAP
+static void ir_tbl_remap_entry_show(struct seq_file *m,
+   struct intel_iommu *iommu)
+{
+   struct irte *ri_entry;
+   int idx;
+
+   seq_puts(m, " Index  SrcID DstIDVct IRTE_high\t\tIRTE_low\n");
+
+   for (idx = 0; idx < INTR_REMAP_TABLE_ENTRIES; idx++) {
+   ri_entry = >ir_table->base[idx];
+   if (!ri_entry->present || ri_entry->p_pst)
+   continue;
+
+   seq_printf(m, " %d\t%04x  %08x %02x  %016llx\t%016llx\n", idx,
+  ri_entry->sid, ri_entry->dest_id, ri_entry->vector,
+  ri_entry->high, ri_entry->low);
+   }
+}
+
+static void ir_tbl_posted_entry_show(struct seq_file *m,
+struct intel_iommu *iommu)
+{
+   struct irte *pi_entry;
+   int idx;
+
+   seq_puts(m, " Index  SrcID PDA_high PDA_low  Vct 
IRTE_high\t\tIRTE_low\n");
+
+   for (idx = 0; idx < INTR_REMAP_TABLE_ENTRIES; idx++) {
+   pi_entry = >ir_table->base[idx];
+   if (!pi_entry->present || !pi_entry->p_pst)
+   continue;
+
+   seq_printf(m, " %d\t%04x  %08x %08x %02x  %016llx\t%016llx\n",
+  idx, pi_entry->sid, pi_entry->pda_h,
+  pi_entry->pda_l << 6, pi_entry->vector,
+  pi_entry->high, pi_entry->low);
+   }
+}
+
+/*
+ * For active IOMMUs go through the Interrupt remapping
+ * table and print valid entries in a table format for
+ * Remapped and Posted Interrupts.
+ */
+static int ir_translation_struct_show(struct seq_file *m, void *unused)
+{
+   struct dmar_drhd_unit *drhd;
+   struct intel_iommu *iommu;
+   u64 irta;
+
+   rcu_read_lock();
+   for_each_active_iommu(iommu, drhd) {
+   if (!ecap_ir_support(iommu->ecap))
+   continue;
+
+   irta = dmar_readq(iommu->reg + DMAR_IRTA_REG) & VTD_PAGE_MASK;
+   seq_printf(m, "Remapped Interrupt supported on IOMMU: %s\n"
+ " IR table address:%llx\n", iommu->name, irta);
+
+   if (iommu->ir_table && irta)
+   ir_tbl_remap_entry_show(m, iommu);
+   else
+   seq_puts(m, "Interrupt Remapping is not enabled\n");
+   seq_putc(m, '\n');
+   }
+
+   seq_puts(m, "\n\n");
+
+   for_each_active_iommu(iommu, drhd) {
+   if (!cap_pi_support(iommu->cap))
+   continue;
+
+   irta = dmar_readq(iommu->reg + DMAR_IRTA_REG) & VTD_PAGE_MASK;
+   seq_printf(m, "Posted Interrupt supported on IOMMU: %s\n"
+ " IR table 

[PATCH v7 5/5] iommu/vt-d: Add debugfs support for Interrupt remapping

[Sohil Mehta]

Debugfs extension for Intel IOMMU to dump Interrupt remapping table
entries for Interrupt remapping and Interrupt posting.

The file /sys/kernel/debug/intel_iommu/ir_translation_struct provides
detailed information, such as Index, Source Id, Destination Id, Vector
and the IRTE values for entries with the present bit set, in the format
shown.

Remapped Interrupt supported on IOMMU: dmar7
 IR table address:85e50
 Index  SrcID DstIDVct IRTE_highIRTE_low
 1  f0f8  0100 30  0004f0f8 013d
 7  f0f8  0400 22  0004f0f8 0422000d

Posted Interrupt supported on IOMMU: dmar5
 IR table address:85ec0
 Index  SrcID PDA_high PDA_low  Vct IRTE_high   IRTE_low
 4  4300  000f ff765980 41  000f00044300ff76598000418001
 5  4300  000f ff765980 51  000f00044300ff76598000518001

Cc: Jacob Pan 
Cc: Fenghua Yu 
Cc: Ashok Raj 
Co-Developed-by: Gayatri Kammela 
Signed-off-by: Gayatri Kammela 
Signed-off-by: Sohil Mehta 
---

v7: Print the IR table physical base address
Simplify IR table formatting

v6: Change a couple of seq_puts to seq_putc

v5: Fix seq_puts formatting and remove leading '\n's

v4: Remove the unused function parameter
Fix checkpatch.pl warnings
Remove error reporting for debugfs_create_file function
Remove redundant IOMMU null check under for_each_active_iommu

v3: Use a macro for seq file operations 
Change the intel_iommu_interrupt_remap file name to ir_translation_struct

v2: Handle the case when IR is not enabled. Fix seq_printf formatting

 drivers/iommu/intel-iommu-debug.c | 94 +++
 1 file changed, 94 insertions(+)

diff --git a/drivers/iommu/intel-iommu-debug.c 
b/drivers/iommu/intel-iommu-debug.c
index a9a99aa..b66a073 100644
--- a/drivers/iommu/intel-iommu-debug.c
+++ b/drivers/iommu/intel-iommu-debug.c
@@ -229,6 +229,96 @@ static int iommu_regset_show(struct seq_file *m, void 
*unused)
 }
 DEFINE_SHOW_ATTRIBUTE(iommu_regset);
 
+#ifdef CONFIG_IRQ_REMAP
+static void ir_tbl_remap_entry_show(struct seq_file *m,
+   struct intel_iommu *iommu)
+{
+   struct irte *ri_entry;
+   int idx;
+
+   seq_puts(m, " Index  SrcID DstIDVct IRTE_high\t\tIRTE_low\n");
+
+   for (idx = 0; idx < INTR_REMAP_TABLE_ENTRIES; idx++) {
+   ri_entry = >ir_table->base[idx];
+   if (!ri_entry->present || ri_entry->p_pst)
+   continue;
+
+   seq_printf(m, " %d\t%04x  %08x %02x  %016llx\t%016llx\n", idx,
+  ri_entry->sid, ri_entry->dest_id, ri_entry->vector,
+  ri_entry->high, ri_entry->low);
+   }
+}
+
+static void ir_tbl_posted_entry_show(struct seq_file *m,
+struct intel_iommu *iommu)
+{
+   struct irte *pi_entry;
+   int idx;
+
+   seq_puts(m, " Index  SrcID PDA_high PDA_low  Vct 
IRTE_high\t\tIRTE_low\n");
+
+   for (idx = 0; idx < INTR_REMAP_TABLE_ENTRIES; idx++) {
+   pi_entry = >ir_table->base[idx];
+   if (!pi_entry->present || !pi_entry->p_pst)
+   continue;
+
+   seq_printf(m, " %d\t%04x  %08x %08x %02x  %016llx\t%016llx\n",
+  idx, pi_entry->sid, pi_entry->pda_h,
+  pi_entry->pda_l << 6, pi_entry->vector,
+  pi_entry->high, pi_entry->low);
+   }
+}
+
+/*
+ * For active IOMMUs go through the Interrupt remapping
+ * table and print valid entries in a table format for
+ * Remapped and Posted Interrupts.
+ */
+static int ir_translation_struct_show(struct seq_file *m, void *unused)
+{
+   struct dmar_drhd_unit *drhd;
+   struct intel_iommu *iommu;
+   u64 irta;
+
+   rcu_read_lock();
+   for_each_active_iommu(iommu, drhd) {
+   if (!ecap_ir_support(iommu->ecap))
+   continue;
+
+   irta = dmar_readq(iommu->reg + DMAR_IRTA_REG) & VTD_PAGE_MASK;
+   seq_printf(m, "Remapped Interrupt supported on IOMMU: %s\n"
+ " IR table address:%llx\n", iommu->name, irta);
+
+   if (iommu->ir_table && irta)
+   ir_tbl_remap_entry_show(m, iommu);
+   else
+   seq_puts(m, "Interrupt Remapping is not enabled\n");
+   seq_putc(m, '\n');
+   }
+
+   seq_puts(m, "\n\n");
+
+   for_each_active_iommu(iommu, drhd) {
+   if (!cap_pi_support(iommu->cap))
+   continue;
+
+   irta = dmar_readq(iommu->reg + DMAR_IRTA_REG) & VTD_PAGE_MASK;
+   seq_printf(m, "Posted Interrupt supported on IOMMU: %s\n"
+ " IR table address:%llx\n", iommu->name, irta);
+
+   if (iommu->ir_table && irta)
+   ir_tbl_posted_entry_show(m, iommu);
+   else