Re: [PATCH v6 5/5] iommu/vt-d: Add debugfs support for Interrupt remapping

[Andy Shevchenko]

On Tue, 2018-01-09 at 19:48 -0800, Sohil Mehta wrote:
> 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 raw values for entries with the present bit set, in the format
> shown.
> 
> Remapped Interrupt supported on IOMMU: dmar5
>  IR table address:93e09d54c310
> ---
>  Index  SID  Dest_ID  Vct Raw_value_high   Raw_value_low
>  1  3a00 0600 2c  00043a00 062c0009
>  1114301 0900 a2  00044301 09a20009
> 
> Posted Interrupt supported on IOMMU: dmar5
>  IR table address:93e09d54c310
> 
>  Index  SID  PDA_high PDA_low  Vct Raw_value_high   Raw_value_low
>  4  4300 0010 40c7c880 41  00144300 40c7c88000418001
>  5  4300 0010 40c7c880 51  00144300 40c7c88000518001
> 
> 

> + seq_printf(m, "Remapped Interrupt supported on IOMMU:
> %s\n"
> +" IR table address:%p\n", iommu->name,
> +iommu->ir_table);

A nit: If you indent second part of string literal to follow the
indentation of first one, it would be slightly better for my opinion.

> + seq_printf(m, "Posted Interrupt supported on IOMMU:
> %s\n"
> +" IR table address:%p\n", iommu->name,
> +iommu->ir_table);

Ditto.

-- 
Andy Shevchenko 
Intel Finland Oy
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[PATCH v6 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 raw values for entries with the present bit set, in the format
shown.

Remapped Interrupt supported on IOMMU: dmar5
 IR table address:93e09d54c310
---
 Index  SID  Dest_ID  Vct Raw_value_high   Raw_value_low
 1  3a00 0600 2c  00043a00 062c0009
 1114301 0900 a2  00044301 09a20009

Posted Interrupt supported on IOMMU: dmar5
 IR table address:93e09d54c310

 Index  SID  PDA_high PDA_low  Vct Raw_value_high   Raw_value_low
 4  4300 0010 40c7c880 41  00144300 40c7c88000418001
 5  4300 0010 40c7c880 51  00144300 40c7c88000518001

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

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 | 98 +++
 1 file changed, 98 insertions(+)

diff --git a/drivers/iommu/intel-iommu-debug.c 
b/drivers/iommu/intel-iommu-debug.c
index d25f7c99..b714c6f 100644
--- a/drivers/iommu/intel-iommu-debug.c
+++ b/drivers/iommu/intel-iommu-debug.c
@@ -4,6 +4,7 @@
  *
  * Authors: Gayatri Kammela 
  *  Jacob Pan 
+ *  Sohil Mehta 
  *
  */
 
@@ -231,6 +232,98 @@ 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)
+{
+   int idx;
+   struct irte *ri_entry;
+
+   /* Print the header only once */
+   seq_puts(m, " Index  SID  Dest_ID  Vct Raw_value_high   
Raw_value_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 %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)
+{
+   int idx;
+   struct irte *pi_entry;
+
+   /* Print the header only once */
+   seq_puts(m, " Index  SID  PDA_high PDA_low  Vct Raw_value_high   
Raw_value_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 %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;
+
+   rcu_read_lock();
+   for_each_active_iommu(iommu, drhd) {
+   if (!ecap_ir_support(iommu->ecap))
+   continue;
+
+   seq_printf(m, "Remapped Interrupt supported on IOMMU: %s\n"
+  " IR table address:%p\n", iommu->name,
+  iommu->ir_table);
+   seq_puts(m, 
"---\n");
+
+   if (iommu->ir_table)
+   ir_tbl_remap_entry_show(m, iommu);
+   else
+   seq_puts(m, "Interrupt Remapping is not enabled\n");
+   seq_putc(m, '\n');
+   }
+
+   seq_puts(m, "\t\t\t\t\t\t\t\n");
+
+