Documentation/ABI/testing/debugfs-intel-iommu

   1 What:           /sys/kernel/debug/iommu/intel/iommu_regset
   2 Date:           December 2023
   3 Contact:        Jingqi Liu <Jingqi.liu@intel.com>
   4 Description:
   5                 This file dumps all the register contents for each IOMMU device.
   6
   7                 Example in Kabylake:
   8
   9                 ::
  10
  11                  $ sudo cat /sys/kernel/debug/iommu/intel/iommu_regset
  12
  13                  IOMMU: dmar0 Register Base Address: 26be37000
  14
  15                  Name                    Offset          Contents
  16                  VER                     0x00            0x0000000000000010
  17                  GCMD                    0x18            0x0000000000000000
  18                  GSTS                    0x1c            0x00000000c7000000
  19                  FSTS                    0x34            0x0000000000000000
  20                  FECTL                   0x38            0x0000000000000000
  21
  22                  [...]
  23
  24                  IOMMU: dmar1 Register Base Address: fed90000
  25
  26                  Name                    Offset          Contents
  27                  VER                     0x00            0x0000000000000010
  28                  GCMD                    0x18            0x0000000000000000
  29                  GSTS                    0x1c            0x00000000c7000000
  30                  FSTS                    0x34            0x0000000000000000
  31                  FECTL                   0x38            0x0000000000000000
  32
  33                  [...]
  34
  35                  IOMMU: dmar2 Register Base Address: fed91000
  36
  37                  Name                    Offset          Contents
  38                  VER                     0x00            0x0000000000000010
  39                  GCMD                    0x18            0x0000000000000000
  40                  GSTS                    0x1c            0x00000000c7000000
  41                  FSTS                    0x34            0x0000000000000000
  42                  FECTL                   0x38            0x0000000000000000
  43
  44                  [...]
  45
  46 What:           /sys/kernel/debug/iommu/intel/ir_translation_struct
  47 Date:           December 2023
  48 Contact:        Jingqi Liu <Jingqi.liu@intel.com>
  49 Description:
  50                 This file dumps the table entries for Interrupt
  51                 remapping and Interrupt posting.
  52
  53                 Example in Kabylake:
  54
  55                 ::
  56
  57                  $ sudo cat /sys/kernel/debug/iommu/intel/ir_translation_struct
  58
  59                  Remapped Interrupt supported on IOMMU: dmar0
  60                  IR table address:100900000
  61
  62                  Entry SrcID   DstID    Vct IRTE_high           IRTE_low
  63                  0     00:0a.0 00000080 24  0000000000040050    000000800024000d
  64                  1     00:0a.0 00000001 ef  0000000000040050    0000000100ef000d
  65
  66                  Remapped Interrupt supported on IOMMU: dmar1
  67                  IR table address:100300000
  68                  Entry SrcID   DstID    Vct IRTE_high           IRTE_low
  69                  0     00:02.0 00000002 26  0000000000040010    000000020026000d
  70
  71                  [...]
  72
  73                  ****
  74
  75                  Posted Interrupt supported on IOMMU: dmar0
  76                  IR table address:100900000
  77                  Entry SrcID   PDA_high PDA_low  Vct IRTE_high          IRTE_low
  78
  79 What:           /sys/kernel/debug/iommu/intel/dmar_translation_struct
  80 Date:           December 2023
  81 Contact:        Jingqi Liu <Jingqi.liu@intel.com>
  82 Description:
  83                 This file dumps Intel IOMMU DMA remapping tables, such
  84                 as root table, context table, PASID directory and PASID
  85                 table entries in debugfs. For legacy mode, it doesn't
  86                 support PASID, and hence PASID field is defaulted to
  87                 '-1' and other PASID related fields are invalid.
  88
  89                 Example in Kabylake:
  90
  91                 ::
  92
  93                  $ sudo cat /sys/kernel/debug/iommu/intel/dmar_translation_struct
  94
  95                  IOMMU dmar1: Root Table Address: 0x103027000
  96                  B.D.F   Root_entry
  97                  00:02.0 0x0000000000000000:0x000000010303e001
  98
  99                  Context_entry
 100                  0x0000000000000102:0x000000010303f005
 101
 102                  PASID   PASID_table_entry
 103                  -1      0x0000000000000000:0x0000000000000000:0x0000000000000000
 104
 105                  IOMMU dmar0: Root Table Address: 0x103028000
 106                  B.D.F   Root_entry
 107                  00:0a.0 0x0000000000000000:0x00000001038a7001
 108
 109                  Context_entry
 110                  0x0000000000000000:0x0000000103220e7d
 111
 112                  PASID   PASID_table_entry
 113                  0       0x0000000000000000:0x0000000000800002:0x00000001038a5089
 114
 115                  [...]
 116
 117 What:           /sys/kernel/debug/iommu/intel/invalidation_queue
 118 Date:           December 2023
 119 Contact:        Jingqi Liu <Jingqi.liu@intel.com>
 120 Description:
 121                 This file exports invalidation queue internals of each
 122                 IOMMU device.
 123
 124                 Example in Kabylake:
 125
 126                 ::
 127
 128                  $ sudo cat /sys/kernel/debug/iommu/intel/invalidation_queue
 129
 130                  Invalidation queue on IOMMU: dmar0
 131                  Base: 0x10022e000      Head: 20        Tail: 20
 132                  Index          qw0                    qw1                     qw2
 133                      0   0000000000000014        0000000000000000        0000000000000000
 134                      1   0000000200000025        0000000100059c04        0000000000000000
 135                      2   0000000000000014        0000000000000000        0000000000000000
 136
 137                                 qw3                  status
 138                          0000000000000000        0000000000000000
 139                          0000000000000000        0000000000000000
 140                          0000000000000000        0000000000000000
 141
 142                  [...]
 143
 144                  Invalidation queue on IOMMU: dmar1
 145                  Base: 0x10026e000      Head: 32        Tail: 32
 146                  Index           qw0                     qw1                   status
 147                      0   0000000000000004        0000000000000000         0000000000000000
 148                      1   0000000200000025        0000000100059804         0000000000000000
 149                      2   0000000000000011        0000000000000000         0000000000000000
 150
 151                  [...]
 152
 153 What:           /sys/kernel/debug/iommu/intel/dmar_perf_latency
 154 Date:           December 2023
 155 Contact:        Jingqi Liu <Jingqi.liu@intel.com>
 156 Description:
 157                 This file is used to control and show counts of
 158                 execution time ranges for various types per DMAR.
 159
 160                 Firstly, write a value to
 161                 /sys/kernel/debug/iommu/intel/dmar_perf_latency
 162                 to enable sampling.
 163
 164                 The possible values are as follows:
 165
 166                 * 0 - disable sampling all latency data
 167
 168                 * 1 - enable sampling IOTLB invalidation latency data
 169
 170                 * 2 - enable sampling devTLB invalidation latency data
 171
 172                 * 3 - enable sampling intr entry cache invalidation latency data
 173
 174                 Next, read /sys/kernel/debug/iommu/intel/dmar_perf_latency gives
 175                 a snapshot of sampling result of all enabled monitors.
 176
 177                 Examples in Kabylake:
 178
 179                 ::
 180
 181                  1) Disable sampling all latency data:
 182
 183                  $ sudo echo 0 > /sys/kernel/debug/iommu/intel/dmar_perf_latency
 184
 185                  2) Enable sampling IOTLB invalidation latency data
 186
 187                  $ sudo echo 1 > /sys/kernel/debug/iommu/intel/dmar_perf_latency
 188
 189                  $ sudo cat /sys/kernel/debug/iommu/intel/dmar_perf_latency
 190
 191                  IOMMU: dmar0 Register Base Address: 26be37000
 192                                  <0.1us   0.1us-1us    1us-10us  10us-100us   100us-1ms
 193                  inv_iotlb           0           0           0           0           0
 194
 195                                  1ms-10ms      >=10ms     min(us)     max(us) average(us)
 196                  inv_iotlb           0           0           0           0           0
 197
 198                  [...]
 199
 200                  IOMMU: dmar2 Register Base Address: fed91000
 201                                  <0.1us   0.1us-1us    1us-10us  10us-100us   100us-1ms
 202                  inv_iotlb           0           0          18           0           0
 203
 204                                  1ms-10ms      >=10ms     min(us)     max(us) average(us)
 205                  inv_iotlb           0           0           2           2           2
 206
 207                  3) Enable sampling devTLB invalidation latency data
 208
 209                  $ sudo echo 2 > /sys/kernel/debug/iommu/intel/dmar_perf_latency
 210
 211                  $ sudo cat /sys/kernel/debug/iommu/intel/dmar_perf_latency
 212
 213                  IOMMU: dmar0 Register Base Address: 26be37000
 214                                  <0.1us   0.1us-1us    1us-10us  10us-100us   100us-1ms
 215                  inv_devtlb           0           0           0           0           0
 216
 217                                  >=10ms     min(us)     max(us) average(us)
 218                  inv_devtlb           0           0           0           0
 219
 220                  [...]
 221
 222 What:           /sys/kernel/debug/iommu/intel/<bdf>/domain_translation_struct
 223 Date:           December 2023
 224 Contact:        Jingqi Liu <Jingqi.liu@intel.com>
 225 Description:
 226                 This file dumps a specified page table of Intel IOMMU
 227                 in legacy mode or scalable mode.
 228
 229                 For a device that only supports legacy mode, dump its
 230                 page table by the debugfs file in the debugfs device
 231                 directory. e.g.
 232                 /sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct.
 233
 234                 For a device that supports scalable mode, dump the
 235                 page table of specified pasid by the debugfs file in
 236                 the debugfs pasid directory. e.g.
 237                 /sys/kernel/debug/iommu/intel/0000:00:02.0/1/domain_translation_struct.
 238
 239                 Examples in Kabylake:
 240
 241                 ::
 242
 243                  1) Dump the page table of device "0000:00:02.0" that only supports legacy mode.
 244
 245                  $ sudo cat /sys/kernel/debug/iommu/intel/0000:00:02.0/domain_translation_struct
 246
 247                  Device 0000:00:02.0 @0x1017f8000
 248                  IOVA_PFN                PML5E                   PML4E
 249                  0x000000008d800 |       0x0000000000000000      0x00000001017f9003
 250                  0x000000008d801 |       0x0000000000000000      0x00000001017f9003
 251                  0x000000008d802 |       0x0000000000000000      0x00000001017f9003
 252
 253                  PDPE                    PDE                     PTE
 254                  0x00000001017fa003      0x00000001017fb003      0x000000008d800003
 255                  0x00000001017fa003      0x00000001017fb003      0x000000008d801003
 256                  0x00000001017fa003      0x00000001017fb003      0x000000008d802003
 257
 258                  [...]
 259
 260                  2) Dump the page table of device "0000:00:0a.0" with PASID "1" that
 261                  supports scalable mode.
 262
 263                  $ sudo cat /sys/kernel/debug/iommu/intel/0000:00:0a.0/1/domain_translation_struct
 264
 265                  Device 0000:00:0a.0 with pasid 1 @0x10c112000
 266                  IOVA_PFN                PML5E                   PML4E
 267                  0x0000000000000 |       0x0000000000000000      0x000000010df93003
 268                  0x0000000000001 |       0x0000000000000000      0x000000010df93003
 269                  0x0000000000002 |       0x0000000000000000      0x000000010df93003
 270
 271                  PDPE                    PDE                     PTE
 272                  0x0000000106ae6003      0x0000000104b38003      0x0000000147c00803
 273                  0x0000000106ae6003      0x0000000104b38003      0x0000000147c01803
 274                  0x0000000106ae6003      0x0000000104b38003      0x0000000147c02803
 275
 276                  [...]