| What: /sys/kernel/debug/iommu/intel/iommu_regset |
| Date: December 2023 |
| Contact: Jingqi Liu <Jingqi.liu@intel.com> |
| Description: |
| This file dumps all the register contents for each IOMMU device. |
| |
| Example in Kabylake: |
| |
| :: |
| |
| $ sudo cat /sys/kernel/debug/iommu/intel/iommu_regset |
| |
| IOMMU: dmar0 Register Base Address: 26be37000 |
| |
| Name Offset Contents |
| VER 0x00 0x0000000000000010 |
| GCMD 0x18 0x0000000000000000 |
| GSTS 0x1c 0x00000000c7000000 |
| FSTS 0x34 0x0000000000000000 |
| FECTL 0x38 0x0000000000000000 |
| |
| [...] |
| |
| IOMMU: dmar1 Register Base Address: fed90000 |
| |
| Name Offset Contents |
| VER 0x00 0x0000000000000010 |
| GCMD 0x18 0x0000000000000000 |
| GSTS 0x1c 0x00000000c7000000 |
| FSTS 0x34 0x0000000000000000 |
| FECTL 0x38 0x0000000000000000 |
| |
| [...] |
| |
| IOMMU: dmar2 Register Base Address: fed91000 |
| |
| Name Offset Contents |
| VER 0x00 0x0000000000000010 |
| GCMD 0x18 0x0000000000000000 |
| GSTS 0x1c 0x00000000c7000000 |
| FSTS 0x34 0x0000000000000000 |
| FECTL 0x38 0x0000000000000000 |
| |
| [...] |
| |
| What: /sys/kernel/debug/iommu/intel/ir_translation_struct |
| Date: December 2023 |
| Contact: Jingqi Liu <Jingqi.liu@intel.com> |
| Description: |
| This file dumps the table entries for Interrupt |
| remapping and Interrupt posting. |
| |
| Example in Kabylake: |
| |
| :: |
| |
| $ sudo cat /sys/kernel/debug/iommu/intel/ir_translation_struct |
| |
| Remapped Interrupt supported on IOMMU: dmar0 |
| IR table address:100900000 |
| |
| Entry SrcID DstID Vct IRTE_high IRTE_low |
| 0 00:0a.0 00000080 24 0000000000040050 000000800024000d |
| 1 00:0a.0 00000001 ef 0000000000040050 0000000100ef000d |
| |
| Remapped Interrupt supported on IOMMU: dmar1 |
| IR table address:100300000 |
| Entry SrcID DstID Vct IRTE_high IRTE_low |
| 0 00:02.0 00000002 26 0000000000040010 000000020026000d |
| |
| [...] |
| |
| **** |
| |
| Posted Interrupt supported on IOMMU: dmar0 |
| IR table address:100900000 |
| Entry SrcID PDA_high PDA_low Vct IRTE_high IRTE_low |
| |
| What: /sys/kernel/debug/iommu/intel/dmar_translation_struct |
| Date: December 2023 |
| Contact: Jingqi Liu <Jingqi.liu@intel.com> |
| Description: |
| This file dumps Intel IOMMU DMA remapping tables, such |
| as root table, context table, PASID directory and PASID |
| table entries in debugfs. For legacy mode, it doesn't |
| support PASID, and hence PASID field is defaulted to |
| '-1' and other PASID related fields are invalid. |
| |
| Example in Kabylake: |
| |
| :: |
| |
| $ sudo cat /sys/kernel/debug/iommu/intel/dmar_translation_struct |
| |
| IOMMU dmar1: Root Table Address: 0x103027000 |
| B.D.F Root_entry |
| 00:02.0 0x0000000000000000:0x000000010303e001 |
| |
| Context_entry |
| 0x0000000000000102:0x000000010303f005 |
| |
| PASID PASID_table_entry |
| -1 0x0000000000000000:0x0000000000000000:0x0000000000000000 |
| |
| IOMMU dmar0: Root Table Address: 0x103028000 |
| B.D.F Root_entry |
| 00:0a.0 0x0000000000000000:0x00000001038a7001 |
| |
| Context_entry |
| 0x0000000000000000:0x0000000103220e7d |
| |
| PASID PASID_table_entry |
| 0 0x0000000000000000:0x0000000000800002:0x00000001038a5089 |
| |
| [...] |
| |
| What: /sys/kernel/debug/iommu/intel/invalidation_queue |
| Date: December 2023 |
| Contact: Jingqi Liu <Jingqi.liu@intel.com> |
| Description: |
| This file exports invalidation queue internals of each |
| IOMMU device. |
| |
| Example in Kabylake: |
| |
| :: |
| |
| $ sudo cat /sys/kernel/debug/iommu/intel/invalidation_queue |
| |
| Invalidation queue on IOMMU: dmar0 |
| Base: 0x10022e000 Head: 20 Tail: 20 |
| Index qw0 qw1 qw2 |
| 0 0000000000000014 0000000000000000 0000000000000000 |
| 1 0000000200000025 0000000100059c04 0000000000000000 |
| 2 0000000000000014 0000000000000000 0000000000000000 |
| |
| qw3 status |
| 0000000000000000 0000000000000000 |
| 0000000000000000 0000000000000000 |
| 0000000000000000 0000000000000000 |
| |
| [...] |
| |
| Invalidation queue on IOMMU: dmar1 |
| Base: 0x10026e000 Head: 32 Tail: 32 |
| Index qw0 qw1 status |
| 0 0000000000000004 0000000000000000 0000000000000000 |
| 1 0000000200000025 0000000100059804 0000000000000000 |
| 2 0000000000000011 0000000000000000 0000000000000000 |
| |
| [...] |
| |
| What: /sys/kernel/debug/iommu/intel/dmar_perf_latency |
| Date: December 2023 |
| Contact: Jingqi Liu <Jingqi.liu@intel.com> |
| Description: |
| This file is used to control and show counts of |
| execution time ranges for various types per DMAR. |
| |
| Firstly, write a value to |
| /sys/kernel/debug/iommu/intel/dmar_perf_latency |
| to enable sampling. |
| |
| The possible values are as follows: |
| |
| * 0 - disable sampling all latency data |
| |
| * 1 - enable sampling IOTLB invalidation latency data |
| |
| * 2 - enable sampling devTLB invalidation latency data |
| |
| * 3 - enable sampling intr entry cache invalidation latency data |
| |
| Next, read /sys/kernel/debug/iommu/intel/dmar_perf_latency gives |
| a snapshot of sampling result of all enabled monitors. |
| |
| Examples in Kabylake: |
| |
| :: |
| |
| 1) Disable sampling all latency data: |
| |
| $ sudo echo 0 > /sys/kernel/debug/iommu/intel/dmar_perf_latency |
| |
| 2) Enable sampling IOTLB invalidation latency data |
| |
| $ sudo echo 1 > /sys/kernel/debug/iommu/intel/dmar_perf_latency |
| |
| $ sudo cat /sys/kernel/debug/iommu/intel/dmar_perf_latency |
| |
| IOMMU: dmar0 Register Base Address: 26be37000 |
| <0.1us 0.1us-1us 1us-10us 10us-100us 100us-1ms |
| inv_iotlb 0 0 0 0 0 |
| |
| 1ms-10ms >=10ms min(us) max(us) average(us) |
| inv_iotlb 0 0 0 0 0 |
| |
| [...] |
| |
| IOMMU: dmar2 Register Base Address: fed91000 |
| <0.1us 0.1us-1us 1us-10us 10us-100us 100us-1ms |
| inv_iotlb 0 0 18 0 0 |
| |
| 1ms-10ms >=10ms min(us) max(us) average(us) |
| inv_iotlb 0 0 2 2 2 |
| |
| 3) Enable sampling devTLB invalidation latency data |
| |
| $ sudo echo 2 > /sys/kernel/debug/iommu/intel/dmar_perf_latency |
| |
| $ sudo cat /sys/kernel/debug/iommu/intel/dmar_perf_latency |
| |
| IOMMU: dmar0 Register Base Address: 26be37000 |
| <0.1us 0.1us-1us 1us-10us 10us-100us 100us-1ms |
| inv_devtlb 0 0 0 0 0 |
| |
| >=10ms min(us) max(us) average(us) |
| inv_devtlb 0 0 0 0 |
| |
| [...] |
| |
| What: /sys/kernel/debug/iommu/intel/<bdf>/domain_translation_struct |
| Date: December 2023 |
| Contact: Jingqi Liu <Jingqi.liu@intel.com> |
| Description: |
| This file dumps a specified page table of Intel IOMMU |
| in legacy mode or scalable mode. |
| |
| For a device that only supports legacy mode, dump its |
| page table by the debugfs file in the debugfs device |
| directory. e.g. |
| /sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct. |
| |
| For a device that supports scalable mode, dump the |
| page table of specified pasid by the debugfs file in |
| the debugfs pasid directory. e.g. |
| /sys/kernel/debug/iommu/intel/0000:00:02.0/1/domain_translation_struct. |
| |
| Examples in Kabylake: |
| |
| :: |
| |
| 1) Dump the page table of device "0000:00:02.0" that only supports legacy mode. |
| |
| $ sudo cat /sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct |
| |
| Device 0000:00:02.0 @0x1017f8000 |
| IOVA_PFN PML5E PML4E |
| 0x000000008d800 | 0x0000000000000000 0x00000001017f9003 |
| 0x000000008d801 | 0x0000000000000000 0x00000001017f9003 |
| 0x000000008d802 | 0x0000000000000000 0x00000001017f9003 |
| |
| PDPE PDE PTE |
| 0x00000001017fa003 0x00000001017fb003 0x000000008d800003 |
| 0x00000001017fa003 0x00000001017fb003 0x000000008d801003 |
| 0x00000001017fa003 0x00000001017fb003 0x000000008d802003 |
| |
| [...] |
| |
| 2) Dump the page table of device "0000:00:0a.0" with PASID "1" that |
| supports scalable mode. |
| |
| $ sudo cat /sys/kernel/debug/iommu/intel/0000:00:0a.0/1/domain_translation_struct |
| |
| Device 0000:00:0a.0 with pasid 1 @0x10c112000 |
| IOVA_PFN PML5E PML4E |
| 0x0000000000000 | 0x0000000000000000 0x000000010df93003 |
| 0x0000000000001 | 0x0000000000000000 0x000000010df93003 |
| 0x0000000000002 | 0x0000000000000000 0x000000010df93003 |
| |
| PDPE PDE PTE |
| 0x0000000106ae6003 0x0000000104b38003 0x0000000147c00803 |
| 0x0000000106ae6003 0x0000000104b38003 0x0000000147c01803 |
| 0x0000000106ae6003 0x0000000104b38003 0x0000000147c02803 |
| |
| [...] |
