1QEMU-CPU-MODELS(7)                   QEMU                   QEMU-CPU-MODELS(7)
2
3
4

NAME

6       qemu-cpu-models - QEMU CPU Models
7

SYNOPSIS

9       QEMU CPU Modelling Infrastructure manual
10

DESCRIPTION

12   Recommendations for KVM CPU model configuration on x86 hosts
13       The  information  that follows provides recommendations for configuring
14       CPU models on x86 hosts. The goals are to maximise  performance,  while
15       protecting  guest OS against various CPU hardware flaws, and optionally
16       enabling live migration between hosts with heterogeneous CPU models.
17
18   Two ways to configure CPU models with QEMU / KVM
19       1. Host passthrough
20
21          This passes the host CPU model features, model, stepping, exactly to
22          the guest. Note that KVM may filter out some host CPU model features
23          if they cannot be supported with virtualization. Live  migration  is
24          unsafe  when  this mode is used as libvirt / QEMU cannot guarantee a
25          stable CPU is exposed to the guest across hosts. This is the  recom‐
26          mended CPU to use, provided live migration is not required.
27
28       2. Named model
29
30          QEMU  comes with a number of predefined named CPU models, that typi‐
31          cally refer to specific generations of hardware  released  by  Intel
32          and  AMD.   These  allow the guest VMs to have a degree of isolation
33          from the host CPU, allowing greater flexibility  in  live  migrating
34          between hosts with differing hardware.  @end table
35
36       In  both  cases,  it is possible to optionally add or remove individual
37       CPU features, to alter what is presented to the guest by default.
38
39       Libvirt supports a third way to configure CPU  models  known  as  "Host
40       model".   This uses the QEMU "Named model" feature, automatically pick‐
41       ing a CPU model that is similar the host CPU,  and  then  adding  extra
42       features  to  approximate  the  host model as closely as possible. This
43       does not guarantee the CPU family, stepping, etc will  precisely  match
44       the  host CPU, as they would with "Host passthrough", but gives much of
45       the benefit of passthrough, while making live migration safe.
46
47   ABI compatibility levels for CPU models
48       The x86_64 architecture has a number of ABI  compatibility  levels  de‐
49       fined.  Traditionally  most operating systems and toolchains would only
50       target the original baseline ABI. It is expected that in future OS  and
51       toolchains  are likely to target newer ABIs. The table that follows il‐
52       lustrates which ABI compatibility levels can be satisfied by  the  QEMU
53       CPU  models.  Note  that  the table only lists the long term stable CPU
54       model versions (eg Haswell-v4).  In addition to what is  listed,  there
55       are  also many CPU model aliases which resolve to a different CPU model
56       version, depending on the machine type is in use.
57
58   x86-64 ABI compatibility levels
59                     ┌───────────────┬──────────┬────┬────┬────┐
60                     │Model          │ baseline │ v2 │ v3 │ v4 │
61                     ├───────────────┼──────────┼────┼────┼────┤
62                     │486-v1         │          │    │    │    │
63                     ├───────────────┼──────────┼────┼────┼────┤
64                     │Broadwell-v1   │ ✅       │ ✅ │ ✅ │    │
65                     └───────────────┴──────────┴────┴────┴────┘
66
67                     │Broadwell-v2   │ ✅       │ ✅ │ ✅ │    │
68                     ├───────────────┼──────────┼────┼────┼────┤
69                     │Broadwell-v3   │ ✅       │ ✅ │ ✅ │    │
70                     ├───────────────┼──────────┼────┼────┼────┤
71                     │Broadwell-v4   │ ✅       │ ✅ │ ✅ │    │
72                     ├───────────────┼──────────┼────┼────┼────┤
73                     │Cascade‐       │ ✅       │ ✅ │ ✅ │ ✅ │
74                     │lake-Server-v1 │          │    │    │    │
75                     ├───────────────┼──────────┼────┼────┼────┤
76                     │Cascade‐       │ ✅       │ ✅ │ ✅ │ ✅ │
77                     │lake-Server-v2 │          │    │    │    │
78                     ├───────────────┼──────────┼────┼────┼────┤
79                     │Cascade‐       │ ✅       │ ✅ │ ✅ │ ✅ │
80                     │lake-Server-v3 │          │    │    │    │
81                     ├───────────────┼──────────┼────┼────┼────┤
82                     │Cascade‐       │ ✅       │ ✅ │ ✅ │ ✅ │
83                     │lake-Server-v4 │          │    │    │    │
84                     ├───────────────┼──────────┼────┼────┼────┤
85                     │Conroe-v1      │ ✅       │    │    │    │
86                     ├───────────────┼──────────┼────┼────┼────┤
87                     │Cooperlake-v1  │ ✅       │ ✅ │ ✅ │ ✅ │
88                     ├───────────────┼──────────┼────┼────┼────┤
89                     │Denverton-v1   │ ✅       │ ✅ │    │    │
90                     ├───────────────┼──────────┼────┼────┼────┤
91                     │Denverton-v2   │ ✅       │ ✅ │    │    │
92                     ├───────────────┼──────────┼────┼────┼────┤
93                     │Dhyana-v1      │ ✅       │ ✅ │ ✅ │    │
94                     ├───────────────┼──────────┼────┼────┼────┤
95                     │EPYC-Milan-v1  │ ✅       │ ✅ │ ✅ │    │
96                     ├───────────────┼──────────┼────┼────┼────┤
97                     │EPYC-Rome-v1   │ ✅       │ ✅ │ ✅ │    │
98                     ├───────────────┼──────────┼────┼────┼────┤
99                     │EPYC-Rome-v2   │ ✅       │ ✅ │ ✅ │    │
100                     ├───────────────┼──────────┼────┼────┼────┤
101                     │EPYC-v1        │ ✅       │ ✅ │ ✅ │    │
102                     ├───────────────┼──────────┼────┼────┼────┤
103                     │EPYC-v2        │ ✅       │ ✅ │ ✅ │    │
104                     ├───────────────┼──────────┼────┼────┼────┤
105                     │EPYC-v3        │ ✅       │ ✅ │ ✅ │    │
106                     ├───────────────┼──────────┼────┼────┼────┤
107                     │Haswell-v1     │ ✅       │ ✅ │ ✅ │    │
108                     ├───────────────┼──────────┼────┼────┼────┤
109                     │Haswell-v2     │ ✅       │ ✅ │ ✅ │    │
110                     ├───────────────┼──────────┼────┼────┼────┤
111                     │Haswell-v3     │ ✅       │ ✅ │ ✅ │    │
112                     ├───────────────┼──────────┼────┼────┼────┤
113                     │Haswell-v4     │ ✅       │ ✅ │ ✅ │    │
114                     ├───────────────┼──────────┼────┼────┼────┤
115                     │Ice‐           │ ✅       │ ✅ │ ✅ │    │
116                     │lake-Client-v1 │          │    │    │    │
117                     ├───────────────┼──────────┼────┼────┼────┤
118                     │Ice‐           │ ✅       │ ✅ │ ✅ │    │
119                     │lake-Client-v2 │          │    │    │    │
120                     ├───────────────┼──────────┼────┼────┼────┤
121                     │Ice‐           │ ✅       │ ✅ │ ✅ │ ✅ │
122                     │lake-Server-v1 │          │    │    │    │
123                     ├───────────────┼──────────┼────┼────┼────┤
124                     │Ice‐           │ ✅       │ ✅ │ ✅ │ ✅ │
125                     │lake-Server-v2 │          │    │    │    │
126                     ├───────────────┼──────────┼────┼────┼────┤
127                     │Ice‐           │ ✅       │ ✅ │ ✅ │ ✅ │
128                     │lake-Server-v3 │          │    │    │    │
129                     └───────────────┴──────────┴────┴────┴────┘
130
131
132
133                     │Ice‐           │ ✅       │ ✅ │ ✅ │ ✅ │
134                     │lake-Server-v4 │          │    │    │    │
135                     ├───────────────┼──────────┼────┼────┼────┤
136                     │IvyBridge-v1   │ ✅       │ ✅ │    │    │
137                     ├───────────────┼──────────┼────┼────┼────┤
138                     │IvyBridge-v2   │ ✅       │ ✅ │    │    │
139                     ├───────────────┼──────────┼────┼────┼────┤
140                     │KnightsMill-v1 │ ✅       │ ✅ │ ✅ │    │
141                     ├───────────────┼──────────┼────┼────┼────┤
142                     │Nehalem-v1     │ ✅       │ ✅ │    │    │
143                     ├───────────────┼──────────┼────┼────┼────┤
144                     │Nehalem-v2     │ ✅       │ ✅ │    │    │
145                     ├───────────────┼──────────┼────┼────┼────┤
146                     │Opteron_G1-v1  │ ✅       │    │    │    │
147                     ├───────────────┼──────────┼────┼────┼────┤
148                     │Opteron_G2-v1  │ ✅       │    │    │    │
149                     ├───────────────┼──────────┼────┼────┼────┤
150                     │Opteron_G3-v1  │ ✅       │    │    │    │
151                     ├───────────────┼──────────┼────┼────┼────┤
152                     │Opteron_G4-v1  │ ✅       │ ✅ │    │    │
153                     ├───────────────┼──────────┼────┼────┼────┤
154                     │Opteron_G5-v1  │ ✅       │ ✅ │    │    │
155                     ├───────────────┼──────────┼────┼────┼────┤
156                     │Penryn-v1      │ ✅       │    │    │    │
157                     ├───────────────┼──────────┼────┼────┼────┤
158                     │SandyBridge-v1 │ ✅       │ ✅ │    │    │
159                     ├───────────────┼──────────┼────┼────┼────┤
160                     │SandyBridge-v2 │ ✅       │ ✅ │    │    │
161                     ├───────────────┼──────────┼────┼────┼────┤
162                     │Sky‐           │ ✅       │ ✅ │ ✅ │    │
163                     │lake-Client-v1 │          │    │    │    │
164                     ├───────────────┼──────────┼────┼────┼────┤
165                     │Sky‐           │ ✅       │ ✅ │ ✅ │    │
166                     │lake-Client-v2 │          │    │    │    │
167                     ├───────────────┼──────────┼────┼────┼────┤
168                     │Sky‐           │ ✅       │ ✅ │ ✅ │    │
169                     │lake-Client-v3 │          │    │    │    │
170                     ├───────────────┼──────────┼────┼────┼────┤
171                     │Sky‐           │ ✅       │ ✅ │ ✅ │ ✅ │
172                     │lake-Server-v1 │          │    │    │    │
173                     ├───────────────┼──────────┼────┼────┼────┤
174                     │Sky‐           │ ✅       │ ✅ │ ✅ │ ✅ │
175                     │lake-Server-v2 │          │    │    │    │
176                     ├───────────────┼──────────┼────┼────┼────┤
177                     │Sky‐           │ ✅       │ ✅ │ ✅ │ ✅ │
178                     │lake-Server-v3 │          │    │    │    │
179                     ├───────────────┼──────────┼────┼────┼────┤
180                     │Sky‐           │ ✅       │ ✅ │ ✅ │ ✅ │
181                     │lake-Server-v4 │          │    │    │    │
182                     ├───────────────┼──────────┼────┼────┼────┤
183                     │Snowridge-v1   │ ✅       │ ✅ │    │    │
184                     ├───────────────┼──────────┼────┼────┼────┤
185                     │Snowridge-v2   │ ✅       │ ✅ │    │    │
186                     ├───────────────┼──────────┼────┼────┼────┤
187                     │Westmere-v1    │ ✅       │ ✅ │    │    │
188                     ├───────────────┼──────────┼────┼────┼────┤
189                     │Westmere-v2    │ ✅       │ ✅ │    │    │
190                     ├───────────────┼──────────┼────┼────┼────┤
191                     │athlon-v1      │          │    │    │    │
192                     ├───────────────┼──────────┼────┼────┼────┤
193                     │core2duo-v1    │ ✅       │    │    │    │
194                     ├───────────────┼──────────┼────┼────┼────┤
195                     │coreduo-v1     │          │    │    │    │
196                     └───────────────┴──────────┴────┴────┴────┘
197
198
199                     │kvm32-v1       │          │    │    │    │
200                     ├───────────────┼──────────┼────┼────┼────┤
201                     │kvm64-v1       │ ✅       │    │    │    │
202                     ├───────────────┼──────────┼────┼────┼────┤
203                     │n270-v1        │          │    │    │    │
204                     ├───────────────┼──────────┼────┼────┼────┤
205                     │pentium-v1     │          │    │    │    │
206                     ├───────────────┼──────────┼────┼────┼────┤
207                     │pentium2-v1    │          │    │    │    │
208                     ├───────────────┼──────────┼────┼────┼────┤
209                     │pentium3-v1    │          │    │    │    │
210                     ├───────────────┼──────────┼────┼────┼────┤
211                     │phenom-v1      │ ✅       │    │    │    │
212                     ├───────────────┼──────────┼────┼────┼────┤
213                     │qemu32-v1      │          │    │    │    │
214                     ├───────────────┼──────────┼────┼────┼────┤
215                     │qemu64-v1      │ ✅       │    │    │    │
216                     └───────────────┴──────────┴────┴────┴────┘
217
218   Preferred CPU models for Intel x86 hosts
219       The following CPU models are preferred for use on Intel hosts.   Admin‐
220       istrators  /  applications  are  recommended  to use the CPU model that
221       matches the generation of the host CPUs in use. In a deployment with  a
222       mixture of host CPU models between machines, if live migration compati‐
223       bility is required, use the newest CPU model that is compatible  across
224       all desired hosts.
225
226       Cascadelake-Server, Cascadelake-Server-noTSX
227              Intel  Xeon Processor (Cascade Lake, 2019), with "stepping" lev‐
228              els 6 or 7 only.  (The Cascade Lake Xeon processor with stepping
229              5 is vulnerable to MDS variants.)
230
231       Skylake-Server, Skylake-Server-IBRS, Skylake-Server-IBRS-noTSX
232              Intel Xeon Processor (Skylake, 2016)
233
234       Skylake-Client, Skylake-Client-IBRS, Skylake-Client-noTSX-IBRS}
235              Intel Core Processor (Skylake, 2015)
236
237       Broadwell, Broadwell-IBRS, Broadwell-noTSX, Broadwell-noTSX-IBRS
238              Intel Core Processor (Broadwell, 2014)
239
240       Haswell, Haswell-IBRS, Haswell-noTSX, Haswell-noTSX-IBRS
241              Intel Core Processor (Haswell, 2013)
242
243       IvyBridge, IvyBridge-IBR
244              Intel Xeon E3-12xx v2 (Ivy Bridge, 2012)
245
246       SandyBridge, SandyBridge-IBRS
247              Intel Xeon E312xx (Sandy Bridge, 2011)
248
249       Westmere, Westmere-IBRS
250              Westmere E56xx/L56xx/X56xx (Nehalem-C, 2010)
251
252       Nehalem, Nehalem-IBRS
253              Intel Core i7 9xx (Nehalem Class Core i7, 2008)
254
255       Penryn Intel Core 2 Duo P9xxx (Penryn Class Core 2, 2007)
256
257       Conroe Intel Celeron_4x0 (Conroe/Merom Class Core 2, 2006)
258
259   Important CPU features for Intel x86 hosts
260       The  following  are important CPU features that should be used on Intel
261       x86 hosts, when available in the host CPU. Some  of  them  require  ex‐
262       plicit  configuration to enable, as they are not included by default in
263       some, or all, of the named CPU models listed above. In general  all  of
264       these  features  are  included  if  using  "Host  passthrough" or "Host
265       model".
266
267       pcid   Recommended to mitigate the cost of the Meltdown (CVE-2017-5754)
268              fix.
269
270              Included  by  default  in Haswell, Broadwell & Skylake Intel CPU
271              models.
272
273              Should be explicitly turned on for  Westmere,  SandyBridge,  and
274              IvyBridge  Intel CPU models. Note that some desktop/mobile West‐
275              mere CPUs cannot support this feature.
276
277       spec-ctrl
278              Required to enable the Spectre v2 (CVE-2017-5715) fix.
279
280              Included by default in Intel CPU models with -IBRS suffix.
281
282              Must be explicitly turned on for Intel CPU models without  -IBRS
283              suffix.
284
285              Requires  the  host CPU microcode to support this feature before
286              it can be used for guest CPUs.
287
288       stibp  Required to enable stronger Spectre v2 (CVE-2017-5715) fixes  in
289              some operating systems.
290
291              Must be explicitly turned on for all Intel CPU models.
292
293              Requires  the  host CPU microcode to support this feature before
294              it can be used for guest CPUs.
295
296       ssbd   Required to enable the CVE-2018-3639 fix.
297
298              Not included by default in any Intel CPU model.
299
300              Must be explicitly turned on for all Intel CPU models.
301
302              Requires the host CPU microcode to support this  feature  before
303              it can be used for guest CPUs.
304
305       pdpe1gb
306              Recommended to allow guest OS to use 1GB size pages.
307
308              Not included by default in any Intel CPU model.
309
310              Should be explicitly turned on for all Intel CPU models.
311
312              Note that not all CPU hardware will support this feature.
313
314       md-clear
315              Required  to  confirm  the  MDS (CVE-2018-12126, CVE-2018-12127,
316              CVE-2018-12130, CVE-2019-11091) fixes.
317
318              Not included by default in any Intel CPU model.
319
320              Must be explicitly turned on for all Intel CPU models.
321
322              Requires the host CPU microcode to support this  feature  before
323              it can be used for guest CPUs.
324
325       mds-no Recommended to inform the guest OS that the host is not vulnera‐
326              ble to any of the MDS variants ([MFBDS] CVE-2018-12130,  [MLPDS]
327              CVE-2018-12127, [MSBDS] CVE-2018-12126).
328
329              This  is  an MSR (Model-Specific Register) feature rather than a
330              CPUID feature, so it will not appear in the Linux  /proc/cpuinfo
331              in the host or guest.  Instead, the host kernel uses it to popu‐
332              late the MDS vulnerability file in sysfs.
333
334              So it should only  be  enabled  for  VMs  if  the  host  reports
335              @code{Not  affected} in the /sys/devices/system/cpu/vulnerabili‐
336              ties/mds file.
337
338       taa-no Recommended to inform that the guest that the host is  not  vul‐
339              nerable to CVE-2019-11135, TSX Asynchronous Abort (TAA).
340
341              This  too is an MSR feature, so it does not show up in the Linux
342              /proc/cpuinfo in the host or guest.
343
344              It should only be enabled for VMs if the host  reports  Not  af‐
345              fected      in      the     /sys/devices/system/cpu/vulnerabili‐
346              ties/tsx_async_abort file.
347
348       tsx-ctrl
349              Recommended to inform the guest that it can  disable  the  Intel
350              TSX  (Transactional  Synchronization Extensions) feature; or, if
351              the processor is vulnerable, use the Intel VERW  instruction  (a
352              processor-level  instruction  that performs checks on memory ac‐
353              cess) as a mitigation for the TAA vulnerability.  (For  details,
354              refer to Intel's deep dive into MDS.)
355
356              Expose this to the guest OS if and only if: (a) the host has TSX
357              enabled; and (b) the guest has rtm CPU flag enabled.
358
359              By disabling TSX, KVM-based guests can avoid paying the price of
360              mitigating TSX-based attacks.
361
362              Note that tsx-ctrl too is an MSR feature, so it does not show up
363              in the Linux /proc/cpuinfo in the host or guest.
364
365              To validate that Intel TSX is indeed  disabled  for  the  guest,
366              there  are  two  ways:  (a)  check for the absence of rtm in the
367              guest's /proc/cpuinfo; or (b)  the  /sys/devices/system/cpu/vul‐
368              nerabilities/tsx_async_abort  file  in  the  guest should report
369              Mitigation: TSX disabled.
370
371   Preferred CPU models for AMD x86 hosts
372       The following CPU models are preferred for use on AMD hosts.   Adminis‐
373       trators  /  applications  are  recommended  to  use  the CPU model that
374       matches the generation of the host CPUs in use. In a deployment with  a
375       mixture of host CPU models between machines, if live migration compati‐
376       bility is required, use the newest CPU model that is compatible  across
377       all desired hosts.
378
379       EPYC, EPYC-IBPB
380              AMD EPYC Processor (2017)
381
382       Opteron_G5
383              AMD Opteron 63xx class CPU (2012)
384
385       Opteron_G4
386              AMD Opteron 62xx class CPU (2011)
387
388       Opteron_G3
389              AMD Opteron 23xx (Gen 3 Class Opteron, 2009)
390
391       Opteron_G2
392              AMD Opteron 22xx (Gen 2 Class Opteron, 2006)
393
394       Opteron_G1
395              AMD Opteron 240 (Gen 1 Class Opteron, 2004)
396
397   Important CPU features for AMD x86 hosts
398       The following are important CPU features that should be used on AMD x86
399       hosts, when available in the host CPU. Some of  them  require  explicit
400       configuration  to  enable, as they are not included by default in some,
401       or all, of the named CPU models listed above. In general all  of  these
402       features are included if using "Host passthrough" or "Host model".
403
404       ibpb   Required to enable the Spectre v2 (CVE-2017-5715) fix.
405
406              Included by default in AMD CPU models with -IBPB suffix.
407
408              Must  be  explicitly  turned on for AMD CPU models without -IBPB
409              suffix.
410
411              Requires the host CPU microcode to support this  feature  before
412              it can be used for guest CPUs.
413
414       stibp  Required  to enable stronger Spectre v2 (CVE-2017-5715) fixes in
415              some operating systems.
416
417              Must be explicitly turned on for all AMD CPU models.
418
419              Requires the host CPU microcode to support this  feature  before
420              it can be used for guest CPUs.
421
422       virt-ssbd
423              Required to enable the CVE-2018-3639 fix
424
425              Not included by default in any AMD CPU model.
426
427              Must be explicitly turned on for all AMD CPU models.
428
429              This should be provided to guests, even if amd-ssbd is also pro‐
430              vided, for maximum guest compatibility.
431
432              Note for some QEMU / libvirt versions, this must  be  force  en‐
433              abled  when  when  using "Host model", because this is a virtual
434              feature that doesn't exist in the physical host CPUs.
435
436       amd-ssbd
437              Required to enable the CVE-2018-3639 fix
438
439              Not included by default in any AMD CPU model.
440
441              Must be explicitly turned on for all AMD CPU models.
442
443              This provides higher performance than virt-ssbd so should be ex‐
444              posed to guests whenever available in the host. virt-ssbd should
445              none the less also be exposed for maximum guest compatibility as
446              some kernels only know about virt-ssbd.
447
448       amd-no-ssb
449              Recommended to indicate the host is not vulnerable CVE-2018-3639
450
451              Not included by default in any AMD CPU model.
452
453              Future  hardware  generations  of  CPU will not be vulnerable to
454              CVE-2018-3639, and thus the guest should be told not  to  enable
455              its mitigations, by exposing amd-no-ssb. This is mutually exclu‐
456              sive with virt-ssbd and amd-ssbd.
457
458       pdpe1gb
459              Recommended to allow guest OS to use 1GB size pages
460
461              Not included by default in any AMD CPU model.
462
463              Should be explicitly turned on for all AMD CPU models.
464
465              Note that not all CPU hardware will support this feature.
466
467   Default x86 CPU models
468       The default QEMU CPU models are designed such that they can run on  all
469       hosts.  If an application does not wish to do perform any host compati‐
470       bility checks before launching guests, the  default  is  guaranteed  to
471       work.
472
473       The  default CPU models will, however, leave the guest OS vulnerable to
474       various CPU hardware flaws, so their use is strongly discouraged.   Ap‐
475       plications  should  follow  the  earlier guidance to setup a better CPU
476       configuration, with host passthrough recommended if live  migration  is
477       not needed.
478
479       qemu32, qemu64
480              QEMU Virtual CPU version 2.5+ (32 & 64 bit variants)
481
482       qemu64  is  used  for x86_64 guests and qemu32 is used for i686 guests,
483       when no -cpu argument is given to QEMU, or no <cpu> is provided in lib‐
484       virt XML.
485
486   Other non-recommended x86 CPUs
487       The  following  CPUs  models are compatible with most AMD and Intel x86
488       hosts, but their usage is discouraged, as they expose  a  very  limited
489       featureset, which prevents guests having optimal performance.
490
491       kvm32, kvm64
492              Common KVM processor (32 & 64 bit variants).
493
494              Legacy  models  just  for  historical compatibility with ancient
495              QEMU versions.
496
497       486, athlon, phenom, coreduo, core2duo, n270, pentium,  pentium2,  pen‐
498       tium3
499              Various  very old x86 CPU models, mostly predating the introduc‐
500              tion of hardware assisted virtualization, that should  thus  not
501              be required for running virtual machines.
502
503   Syntax for configuring CPU models
504       The  examples  below illustrate the approach to configuring the various
505       CPU models / features in QEMU and libvirt.
506
507   QEMU command line
508       Host passthrough:
509
510          qemu-system-x86_64 -cpu host
511
512       Host passthrough with feature customization:
513
514          qemu-system-x86_64 -cpu host,vmx=off,...
515
516       Named CPU models:
517
518          qemu-system-x86_64 -cpu Westmere
519
520       Named CPU models with feature customization:
521
522          qemu-system-x86_64 -cpu Westmere,pcid=on,...
523
524   Libvirt guest XML
525       Host passthrough:
526
527          <cpu mode='host-passthrough'/>
528
529       Host passthrough with feature customization:
530
531          <cpu mode='host-passthrough'>
532              <feature name="vmx" policy="disable"/>
533              ...
534          </cpu>
535
536       Host model:
537
538          <cpu mode='host-model'/>
539
540       Host model with feature customization:
541
542          <cpu mode='host-model'>
543              <feature name="vmx" policy="disable"/>
544              ...
545          </cpu>
546
547       Named model:
548
549          <cpu mode='custom'>
550              <model name="Westmere"/>
551          </cpu>
552
553       Named model with feature customization:
554
555          <cpu mode='custom'>
556              <model name="Westmere"/>
557              <feature name="pcid" policy="require"/>
558              ...
559          </cpu>
560
561   Supported CPU model configurations on MIPS hosts
562       QEMU supports variety of MIPS CPU models:
563
564   Supported CPU models for MIPS32 hosts
565       The following CPU models are supported for use on MIPS32 hosts.  Admin‐
566       istrators  /  applications  are  recommended  to use the CPU model that
567       matches the generation of the host CPUs in use. In a deployment with  a
568       mixture of host CPU models between machines, if live migration compati‐
569       bility is required, use the newest CPU model that is compatible  across
570       all desired hosts.
571
572       mips32r6-generic
573              MIPS32 Processor (Release 6, 2015)
574
575       P5600  MIPS32 Processor (P5600, 2014)
576
577       M14K, M14Kc
578              MIPS32 Processor (M14K, 2009)
579
580       74Kf   MIPS32 Processor (74K, 2007)
581
582       34Kf   MIPS32 Processor (34K, 2006)
583
584       24Kc, 24KEc, 24Kf
585              MIPS32 Processor (24K, 2003)
586
587       4Kc, 4Km, 4KEcR1, 4KEmR1, 4KEc, 4KEm
588              MIPS32 Processor (4K, 1999)
589
590   Supported CPU models for MIPS64 hosts
591       The following CPU models are supported for use on MIPS64 hosts.  Admin‐
592       istrators / applications are recommended to  use  the  CPU  model  that
593       matches  the generation of the host CPUs in use. In a deployment with a
594       mixture of host CPU models between machines, if live migration compati‐
595       bility  is required, use the newest CPU model that is compatible across
596       all desired hosts.
597
598       I6400  MIPS64 Processor (Release 6, 2014)
599
600       Loongson-2E
601              MIPS64 Processor (Loongson 2, 2006)
602
603       Loongson-2F
604              MIPS64 Processor (Loongson 2, 2008)
605
606       Loongson-3A1000
607              MIPS64 Processor (Loongson 3, 2010)
608
609       Loongson-3A4000
610              MIPS64 Processor (Loongson 3, 2018)
611
612       mips64dspr2
613              MIPS64 Processor (Release 2, 2006)
614
615       MIPS64R2-generic, 5KEc, 5KEf
616              MIPS64 Processor (Release 2, 2002)
617
618       20Kc   MIPS64 Processor (20K, 2000
619
620       5Kc, 5Kf
621              MIPS64 Processor (5K, 1999)
622
623       VR5432 MIPS64 Processor (VR, 1998)
624
625       R4000  MIPS64 Processor (MIPS III, 1991)
626
627   Supported CPU models for nanoMIPS hosts
628       The following CPU models are supported for use on nanoMIPS hosts.   Ad‐
629       ministrators  /  applications are recommended to use the CPU model that
630       matches the generation of the host CPUs in use. In a deployment with  a
631       mixture of host CPU models between machines, if live migration compati‐
632       bility is required, use the newest CPU model that is compatible  across
633       all desired hosts.
634
635       I7200  MIPS I7200 (nanoMIPS, 2018)
636
637   Preferred CPU models for MIPS hosts
638       The following CPU models are preferred for use on different MIPS hosts:
639
640       MIPS III
641              R4000
642
643       MIPS32R2
644              34Kf
645
646       MIPS64R6
647              I6400
648
649       nanoMIPS
650              I7200
651

SEE ALSO

653       The  HTML  documentation of QEMU for more precise information and Linux
654       user mode emulator invocation.
655

AUTHOR

657       The QEMU Project developers
658
660       2022, The QEMU Project Developers
661
662
663
664
6656.2.0                            Jun 11, 2022               QEMU-CPU-MODELS(7)
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