1 What: /sys/kernel/debug/iommu/intel/
2 Date: December 2023
3 Contact: Jingqi Liu <Jingqi.liu@intel.co
4 Description:
5 This file dumps all the regist
6
7 Example in Kabylake:
8
9 ::
10
11 $ sudo cat /sys/kernel/debug/
12
13 IOMMU: dmar0 Register Base Ad
14
15 Name Offse
16 VER 0x00
17 GCMD 0x18
18 GSTS 0x1c
19 FSTS 0x34
20 FECTL 0x38
21
22 [...]
23
24 IOMMU: dmar1 Register Base Ad
25
26 Name Offse
27 VER 0x00
28 GCMD 0x18
29 GSTS 0x1c
30 FSTS 0x34
31 FECTL 0x38
32
33 [...]
34
35 IOMMU: dmar2 Register Base Ad
36
37 Name Offse
38 VER 0x00
39 GCMD 0x18
40 GSTS 0x1c
41 FSTS 0x34
42 FECTL 0x38
43
44 [...]
45
46 What: /sys/kernel/debug/iommu/intel/
47 Date: December 2023
48 Contact: Jingqi Liu <Jingqi.liu@intel.co
49 Description:
50 This file dumps the table entr
51 remapping and Interrupt postin
52
53 Example in Kabylake:
54
55 ::
56
57 $ sudo cat /sys/kernel/debug/
58
59 Remapped Interrupt supported
60 IR table address:100900000
61
62 Entry SrcID DstID Vct IR
63 0 00:0a.0 00000080 24 00
64 1 00:0a.0 00000001 ef 00
65
66 Remapped Interrupt supported
67 IR table address:100300000
68 Entry SrcID DstID Vct IR
69 0 00:02.0 00000002 26 00
70
71 [...]
72
73 ****
74
75 Posted Interrupt supported on
76 IR table address:100900000
77 Entry SrcID PDA_high PDA_lo
78
79 What: /sys/kernel/debug/iommu/intel/
80 Date: December 2023
81 Contact: Jingqi Liu <Jingqi.liu@intel.co
82 Description:
83 This file dumps Intel IOMMU DM
84 as root table, context table,
85 table entries in debugfs. For
86 support PASID, and hence PASID
87 '-1' and other PASID related f
88
89 Example in Kabylake:
90
91 ::
92
93 $ sudo cat /sys/kernel/debug/
94
95 IOMMU dmar1: Root Table Addre
96 B.D.F Root_entry
97 00:02.0 0x0000000000000000:0x
98
99 Context_entry
100 0x0000000000000102:0x00000001
101
102 PASID PASID_table_entry
103 -1 0x0000000000000000:0x
104
105 IOMMU dmar0: Root Table Addre
106 B.D.F Root_entry
107 00:0a.0 0x0000000000000000:0x
108
109 Context_entry
110 0x0000000000000000:0x00000001
111
112 PASID PASID_table_entry
113 0 0x0000000000000000:0x
114
115 [...]
116
117 What: /sys/kernel/debug/iommu/intel/
118 Date: December 2023
119 Contact: Jingqi Liu <Jingqi.liu@intel.co
120 Description:
121 This file exports invalidation
122 IOMMU device.
123
124 Example in Kabylake:
125
126 ::
127
128 $ sudo cat /sys/kernel/debug/
129
130 Invalidation queue on IOMMU:
131 Base: 0x10022e000 Head:
132 Index qw0
133 0 0000000000000014
134 1 0000000200000025
135 2 0000000000000014
136
137 qw3
138 0000000000000000
139 0000000000000000
140 0000000000000000
141
142 [...]
143
144 Invalidation queue on IOMMU:
145 Base: 0x10026e000 Head:
146 Index qw0
147 0 0000000000000004
148 1 0000000200000025
149 2 0000000000000011
150
151 [...]
152
153 What: /sys/kernel/debug/iommu/intel/
154 Date: December 2023
155 Contact: Jingqi Liu <Jingqi.liu@intel.co
156 Description:
157 This file is used to control a
158 execution time ranges for vari
159
160 Firstly, write a value to
161 /sys/kernel/debug/iommu/intel/
162 to enable sampling.
163
164 The possible values are as fol
165
166 * 0 - disable sampling all lat
167
168 * 1 - enable sampling IOTLB in
169
170 * 2 - enable sampling devTLB i
171
172 * 3 - enable sampling intr ent
173
174 Next, read /sys/kernel/debug/i
175 a snapshot of sampling result
176
177 Examples in Kabylake:
178
179 ::
180
181 1) Disable sampling all laten
182
183 $ sudo echo 0 > /sys/kernel/d
184
185 2) Enable sampling IOTLB inva
186
187 $ sudo echo 1 > /sys/kernel/d
188
189 $ sudo cat /sys/kernel/debug/
190
191 IOMMU: dmar0 Register Base Ad
192 <0.1us 0.1u
193 inv_iotlb 0
194
195 1ms-10ms
196 inv_iotlb 0
197
198 [...]
199
200 IOMMU: dmar2 Register Base Ad
201 <0.1us 0.1u
202 inv_iotlb 0
203
204 1ms-10ms
205 inv_iotlb 0
206
207 3) Enable sampling devTLB inv
208
209 $ sudo echo 2 > /sys/kernel/d
210
211 $ sudo cat /sys/kernel/debug/
212
213 IOMMU: dmar0 Register Base Ad
214 <0.1us 0.1u
215 inv_devtlb 0
216
217 >=10ms mi
218 inv_devtlb 0
219
220 [...]
221
222 What: /sys/kernel/debug/iommu/intel/
223 Date: December 2023
224 Contact: Jingqi Liu <Jingqi.liu@intel.co
225 Description:
226 This file dumps a specified pa
227 in legacy mode or scalable mod
228
229 For a device that only support
230 page table by the debugfs file
231 directory. e.g.
232 /sys/kernel/debug/iommu/intel/
233
234 For a device that supports sca
235 page table of specified pasid
236 the debugfs pasid directory. e
237 /sys/kernel/debug/iommu/intel/
238
239 Examples in Kabylake:
240
241 ::
242
243 1) Dump the page table of dev
244
245 $ sudo cat /sys/kernel/debug/
246
247 Device 0000:00:02.0 @0x1017f8
248 IOVA_PFN PML5E
249 0x000000008d800 | 0x000
250 0x000000008d801 | 0x000
251 0x000000008d802 | 0x000
252
253 PDPE PDE
254 0x00000001017fa003 0x000
255 0x00000001017fa003 0x000
256 0x00000001017fa003 0x000
257
258 [...]
259
260 2) Dump the page table of dev
261 supports scalable mode.
262
263 $ sudo cat /sys/kernel/debug/
264
265 Device 0000:00:0a.0 with pasi
266 IOVA_PFN PML5E
267 0x0000000000000 | 0x000
268 0x0000000000001 | 0x000
269 0x0000000000002 | 0x000
270
271 PDPE PDE
272 0x0000000106ae6003 0x000
273 0x0000000106ae6003 0x000
274 0x0000000106ae6003 0x000
275
276 [...]
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