xref: /qemu/docs/about/removed-features.rst (revision 513823e7521a09ed7ad1e32e6454bac3b2cbf52d)
1
2Removed features
3================
4
5What follows is a record of recently removed, formerly deprecated
6features that serves as a record for users who have encountered
7trouble after a recent upgrade.
8
9System emulator command line arguments
10--------------------------------------
11
12``-hdachs`` (removed in 2.12)
13'''''''''''''''''''''''''''''
14
15The geometry defined by ``-hdachs c,h,s,t`` should now be specified via
16``-device ide-hd,drive=dr,cyls=c,heads=h,secs=s,bios-chs-trans=t``
17(together with ``-drive if=none,id=dr,...``).
18
19``-net channel`` (removed in 2.12)
20''''''''''''''''''''''''''''''''''
21
22This option has been replaced by ``-net user,guestfwd=...``.
23
24``-net dump`` (removed in 2.12)
25'''''''''''''''''''''''''''''''
26
27``-net dump[,vlan=n][,file=filename][,len=maxlen]`` has been replaced by
28``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=maxlen]``.
29Note that the new syntax works with netdev IDs instead of the old "vlan" hubs.
30
31``-no-kvm-pit`` (removed in 2.12)
32'''''''''''''''''''''''''''''''''
33
34This was just a dummy option that has been ignored, since the in-kernel PIT
35cannot be disabled separately from the irqchip anymore. A similar effect
36(which also disables the KVM IOAPIC) can be obtained with
37``-M kernel_irqchip=split``.
38
39``-tdf`` (removed in 2.12)
40''''''''''''''''''''''''''
41
42There is no replacement, the ``-tdf`` option has just been ignored since the
43behaviour that could be changed by this option in qemu-kvm is now the default
44when using the KVM PIT. It still can be requested explicitly using
45``-global kvm-pit.lost_tick_policy=delay``.
46
47``-drive secs=s``, ``-drive heads=h`` & ``-drive cyls=c`` (removed in 3.0)
48''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
49
50The drive geometry should now be specified via
51``-device ...,drive=dr,cyls=c,heads=h,secs=s`` (together with
52``-drive if=none,id=dr,...``).
53
54``-drive serial=``, ``-drive trans=`` & ``-drive addr=`` (removed in 3.0)
55'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
56
57Use ``-device ...,drive=dr,serial=r,bios-chs-trans=t,addr=a`` instead
58(together with ``-drive if=none,id=dr,...``).
59
60``-net ...,vlan=x`` (removed in 3.0)
61''''''''''''''''''''''''''''''''''''
62
63The term "vlan" was very confusing for most users in this context (it's about
64specifying a hub ID, not about IEEE 802.1Q or something similar), so this
65has been removed. To connect one NIC frontend with a network backend, either
66use ``-nic ...`` (e.g. for on-board NICs) or use ``-netdev ...,id=n`` together
67with ``-device ...,netdev=n`` (for full control over pluggable NICs). To
68connect multiple NICs or network backends via a hub device (which is what
69vlan did), use ``-nic hubport,hubid=x,...`` or
70``-netdev hubport,id=n,hubid=x,...`` (with ``-device ...,netdev=n``) instead.
71
72``-no-kvm-irqchip`` (removed in 3.0)
73''''''''''''''''''''''''''''''''''''
74
75Use ``-machine kernel_irqchip=off`` instead.
76
77``-no-kvm-pit-reinjection`` (removed in 3.0)
78''''''''''''''''''''''''''''''''''''''''''''
79
80Use ``-global kvm-pit.lost_tick_policy=discard`` instead.
81
82``-balloon`` (removed in 3.1)
83'''''''''''''''''''''''''''''
84
85The ``-balloon virtio`` option has been replaced by ``-device virtio-balloon``.
86The ``-balloon none`` option was a no-op and has no replacement.
87
88``-bootp`` (removed in 3.1)
89'''''''''''''''''''''''''''
90
91The ``-bootp /some/file`` argument is replaced by either
92``-netdev user,id=x,bootp=/some/file`` (for pluggable NICs, accompanied with
93``-device ...,netdev=x``), or ``-nic user,bootp=/some/file`` (for on-board NICs).
94The new syntax allows different settings to be provided per NIC.
95
96``-redir`` (removed in 3.1)
97'''''''''''''''''''''''''''
98
99The ``-redir [tcp|udp]:hostport:[guestaddr]:guestport`` option is replaced
100by either ``-netdev
101user,id=x,hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport``
102(for pluggable NICs, accompanied with ``-device ...,netdev=x``) or by the option
103``-nic user,hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport``
104(for on-board NICs). The new syntax allows different settings to be provided
105per NIC.
106
107``-smb`` (removed in 3.1)
108'''''''''''''''''''''''''
109
110The ``-smb /some/dir`` argument is replaced by either
111``-netdev user,id=x,smb=/some/dir`` (for pluggable NICs, accompanied with
112``-device ...,netdev=x``), or ``-nic user,smb=/some/dir`` (for on-board NICs).
113The new syntax allows different settings to be provided per NIC.
114
115``-tftp`` (removed in 3.1)
116''''''''''''''''''''''''''
117
118The ``-tftp /some/dir`` argument is replaced by either
119``-netdev user,id=x,tftp=/some/dir`` (for pluggable NICs, accompanied with
120``-device ...,netdev=x``), or ``-nic user,tftp=/some/dir`` (for embedded NICs).
121The new syntax allows different settings to be provided per NIC.
122
123``-localtime`` (removed in 3.1)
124'''''''''''''''''''''''''''''''
125
126Replaced by ``-rtc base=localtime``.
127
128``-nodefconfig`` (removed in 3.1)
129'''''''''''''''''''''''''''''''''
130
131Use ``-no-user-config`` instead.
132
133``-rtc-td-hack`` (removed in 3.1)
134'''''''''''''''''''''''''''''''''
135
136Use ``-rtc driftfix=slew`` instead.
137
138``-startdate`` (removed in 3.1)
139'''''''''''''''''''''''''''''''
140
141Replaced by ``-rtc base=date``.
142
143``-vnc ...,tls=...``, ``-vnc ...,x509=...`` & ``-vnc ...,x509verify=...`` (removed in 3.1)
144''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
145
146The "tls-creds" option should be used instead to point to a "tls-creds-x509"
147object created using "-object".
148
149``-mem-path`` fallback to RAM (removed in 5.0)
150''''''''''''''''''''''''''''''''''''''''''''''
151
152If guest RAM allocation from file pointed by ``mem-path`` failed,
153QEMU was falling back to allocating from RAM, which might have resulted
154in unpredictable behavior since the backing file specified by the user
155as ignored. Currently, users are responsible for making sure the backing storage
156specified with ``-mem-path`` can actually provide the guest RAM configured with
157``-m`` and QEMU fails to start up if RAM allocation is unsuccessful.
158
159``-net ...,name=...`` (removed in 5.1)
160''''''''''''''''''''''''''''''''''''''
161
162The ``name`` parameter of the ``-net`` option was a synonym
163for the ``id`` parameter, which should now be used instead.
164
165``-numa node,mem=...`` (removed in 5.1)
166'''''''''''''''''''''''''''''''''''''''
167
168The parameter ``mem`` of ``-numa node`` was used to assign a part of guest RAM
169to a NUMA node. But when using it, it's impossible to manage a specified RAM
170chunk on the host side (like bind it to a host node, setting bind policy, ...),
171so the guest ends up with the fake NUMA configuration with suboptiomal
172performance.
173However since 2014 there is an alternative way to assign RAM to a NUMA node
174using parameter ``memdev``, which does the same as ``mem`` and adds
175means to actually manage node RAM on the host side. Use parameter ``memdev``
176with *memory-backend-ram* backend as replacement for parameter ``mem``
177to achieve the same fake NUMA effect or a properly configured
178*memory-backend-file* backend to actually benefit from NUMA configuration.
179New machine versions (since 5.1) will not accept the option but it will still
180work with old machine types. User can check the QAPI schema to see if the legacy
181option is supported by looking at MachineInfo::numa-mem-supported property.
182
183``-numa`` node (without memory specified) (removed in 5.2)
184''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
185
186Splitting RAM by default between NUMA nodes had the same issues as ``mem``
187parameter with the difference that the role of the user plays QEMU using
188implicit generic or board specific splitting rule.
189Use ``memdev`` with *memory-backend-ram* backend or ``mem`` (if
190it's supported by used machine type) to define mapping explicitly instead.
191Users of existing VMs, wishing to preserve the same RAM distribution, should
192configure it explicitly using ``-numa node,memdev`` options. Current RAM
193distribution can be retrieved using HMP command ``info numa`` and if separate
194memory devices (pc|nv-dimm) are present use ``info memory-device`` and subtract
195device memory from output of ``info numa``.
196
197``-smp`` (invalid topologies) (removed in 5.2)
198''''''''''''''''''''''''''''''''''''''''''''''
199
200CPU topology properties should describe whole machine topology including
201possible CPUs.
202
203However, historically it was possible to start QEMU with an incorrect topology
204where *n* <= *sockets* * *cores* * *threads* < *maxcpus*,
205which could lead to an incorrect topology enumeration by the guest.
206Support for invalid topologies is removed, the user must ensure
207topologies described with -smp include all possible cpus, i.e.
208*sockets* * *cores* * *threads* = *maxcpus*.
209
210``-machine enforce-config-section=on|off`` (removed in 5.2)
211'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
212
213The ``enforce-config-section`` property was replaced by the
214``-global migration.send-configuration={on|off}`` option.
215
216``-no-kvm`` (removed in 5.2)
217''''''''''''''''''''''''''''
218
219The ``-no-kvm`` argument was a synonym for setting ``-machine accel=tcg``.
220
221``-realtime`` (removed in 6.0)
222''''''''''''''''''''''''''''''
223
224The ``-realtime mlock=on|off`` argument has been replaced by the
225``-overcommit mem-lock=on|off`` argument.
226
227``-show-cursor`` option (removed in 6.0)
228''''''''''''''''''''''''''''''''''''''''
229
230Use ``-display sdl,show-cursor=on``, ``-display gtk,show-cursor=on``
231or ``-display default,show-cursor=on`` instead.
232
233``-tb-size`` option (removed in 6.0)
234''''''''''''''''''''''''''''''''''''
235
236QEMU 5.0 introduced an alternative syntax to specify the size of the translation
237block cache, ``-accel tcg,tb-size=``.
238
239``-usbdevice audio`` (removed in 6.0)
240'''''''''''''''''''''''''''''''''''''
241
242This option lacked the possibility to specify an audio backend device.
243Use ``-device usb-audio`` now instead (and specify a corresponding USB
244host controller or ``-usb`` if necessary).
245
246``-vnc acl`` (removed in 6.0)
247'''''''''''''''''''''''''''''
248
249The ``acl`` option to the ``-vnc`` argument has been replaced
250by the ``tls-authz`` and ``sasl-authz`` options.
251
252``-mon ...,control=readline,pretty=on|off`` (removed in 6.0)
253''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
254
255The ``pretty=on|off`` switch has no effect for HMP monitors and
256its use is rejected.
257
258``-drive file=json:{...{'driver':'file'}}`` (removed in 6.0)
259''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
260
261The 'file' driver for drives is no longer appropriate for character or host
262devices and will only accept regular files (S_IFREG). The correct driver
263for these file types is 'host_cdrom' or 'host_device' as appropriate.
264
265Floppy controllers' drive properties (removed in 6.0)
266'''''''''''''''''''''''''''''''''''''''''''''''''''''
267
268Use ``-device floppy,...`` instead.  When configuring onboard floppy
269controllers
270::
271
272    -global isa-fdc.driveA=...
273    -global sysbus-fdc.driveA=...
274    -global SUNW,fdtwo.drive=...
275
276become
277::
278
279    -device floppy,unit=0,drive=...
280
281and
282::
283
284    -global isa-fdc.driveB=...
285    -global sysbus-fdc.driveB=...
286
287become
288::
289
290    -device floppy,unit=1,drive=...
291
292When plugging in a floppy controller
293::
294
295    -device isa-fdc,...,driveA=...
296
297becomes
298::
299
300    -device isa-fdc,...
301    -device floppy,unit=0,drive=...
302
303and
304::
305
306    -device isa-fdc,...,driveB=...
307
308becomes
309::
310
311    -device isa-fdc,...
312    -device floppy,unit=1,drive=...
313
314``-drive`` with bogus interface type (removed in 6.0)
315'''''''''''''''''''''''''''''''''''''''''''''''''''''
316
317Drives with interface types other than ``if=none`` are for onboard
318devices.  Drives the board doesn't pick up can no longer be used with
319-device.  Use ``if=none`` instead.
320
321``-usbdevice ccid`` (removed in 6.0)
322'''''''''''''''''''''''''''''''''''''
323
324This option was undocumented and not used in the field.
325Use ``-device usb-ccid`` instead.
326
327RISC-V firmware not booted by default (removed in 5.1)
328''''''''''''''''''''''''''''''''''''''''''''''''''''''
329
330QEMU 5.1 changes the default behaviour from ``-bios none`` to ``-bios default``
331for the RISC-V ``virt`` machine and ``sifive_u`` machine.
332
333``-no-quit`` (removed in 7.0)
334'''''''''''''''''''''''''''''
335
336The ``-no-quit`` was a synonym for ``-display ...,window-close=off`` which
337should be used instead.
338
339``--enable-fips`` (removed in 7.1)
340''''''''''''''''''''''''''''''''''
341
342This option restricted usage of certain cryptographic algorithms when
343the host is operating in FIPS mode.
344
345If FIPS compliance is required, QEMU should be built with the ``libgcrypt``
346or ``gnutls`` library enabled as a cryptography provider.
347
348Neither the ``nettle`` library, or the built-in cryptography provider are
349supported on FIPS enabled hosts.
350
351``-writeconfig`` (removed in 7.1)
352'''''''''''''''''''''''''''''''''
353
354The ``-writeconfig`` option was not able to serialize the entire contents
355of the QEMU command line.  It is thus considered a failed experiment
356and removed without a replacement.
357
358``loaded`` property of secret and TLS credential objects (removed in 9.2)
359'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
360
361The ``loaded=on`` option in the command line or QMP ``object-add`` either had
362no effect (if ``loaded`` was the last option) or caused options to be
363effectively ignored as if they were not given.  The property is therefore
364useless and has been removed.
365
366``opened`` property of ``rng-*`` objects (removed in 7.1)
367'''''''''''''''''''''''''''''''''''''''''''''''''''''''''
368
369The ``opened=on`` option in the command line or QMP ``object-add`` either had
370no effect (if ``opened`` was the last option) or caused errors.  The property
371is therefore useless and should simply be removed.
372
373``-display sdl,window_close=...`` (removed in 7.1)
374''''''''''''''''''''''''''''''''''''''''''''''''''
375
376Use ``-display sdl,window-close=...`` instead (i.e. with a minus instead of
377an underscore between "window" and "close").
378
379``-alt-grab`` and ``-display sdl,alt_grab=on`` (removed in 7.1)
380'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
381
382Use ``-display sdl,grab-mod=lshift-lctrl-lalt`` instead.
383
384``-ctrl-grab`` and ``-display sdl,ctrl_grab=on`` (removed in 7.1)
385'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
386
387Use ``-display sdl,grab-mod=rctrl`` instead.
388
389``-sdl`` (removed in 7.1)
390'''''''''''''''''''''''''
391
392Use ``-display sdl`` instead.
393
394``-curses`` (removed in 7.1)
395''''''''''''''''''''''''''''
396
397Use ``-display curses`` instead.
398
399Creating sound card devices using ``-soundhw`` (removed in 7.1)
400'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
401
402Sound card devices should be created using ``-device`` or ``-audio``.
403The exception is ``pcspk`` which can be activated using ``-machine
404pcspk-audiodev=<name>``.
405
406``-watchdog`` (removed in 7.2)
407''''''''''''''''''''''''''''''
408
409Use ``-device`` instead.
410
411Hexadecimal sizes with scaling multipliers (removed in 8.0)
412'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
413
414Input parameters that take a size value should only use a size suffix
415(such as 'k' or 'M') when the base is written in decimal, and not when
416the value is hexadecimal.  That is, '0x20M' should be written either as
417'32M' or as '0x2000000'.
418
419``-chardev`` backend aliases ``tty`` and ``parport`` (removed in 8.0)
420'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
421
422``tty`` and ``parport`` used to be aliases for ``serial`` and ``parallel``
423respectively. The actual backend names should be used instead.
424
425``-drive if=none`` for the sifive_u OTP device (removed in 8.0)
426'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
427
428Use ``-drive if=pflash`` to configure the OTP device of the sifive_u
429RISC-V machine instead.
430
431``-spice password=string`` (removed in 8.0)
432'''''''''''''''''''''''''''''''''''''''''''
433
434This option was insecure because the SPICE password remained visible in
435the process listing. This was replaced by the new ``password-secret``
436option which lets the password be securely provided on the command
437line using a ``secret`` object instance.
438
439``QEMU_AUDIO_`` environment variables and ``-audio-help`` (removed in 8.2)
440''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
441
442The ``-audiodev`` and ``-audio`` command line options are now the only
443way to specify audio backend settings.
444
445Using ``-audiodev`` to define the default audio backend (removed in 8.2)
446''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
447
448If no audiodev property is specified, previous versions would use the
449first ``-audiodev`` command line option as a fallback.  Starting with
450version 8.2, audio backends created with ``-audiodev`` will only be
451used by clients (sound cards, machines with embedded sound hardware, VNC)
452that refer to it in an ``audiodev=`` property.
453
454In order to configure a default audio backend, use the ``-audio``
455command line option without specifying a ``model``; while previous
456versions of QEMU required a model, starting with version 8.2
457QEMU does not require a model and will not create any sound card
458in this case.
459
460Note that the default audio backend must be configured on the command
461line if the ``-nodefaults`` options is used.
462
463``-no-hpet`` (removed in 9.0)
464'''''''''''''''''''''''''''''
465
466The HPET setting has been turned into a machine property.
467Use ``-machine hpet=off`` instead.
468
469``-no-acpi`` (removed in 9.0)
470'''''''''''''''''''''''''''''
471
472The ``-no-acpi`` setting has been turned into a machine property.
473Use ``-machine acpi=off`` instead.
474
475``-async-teardown`` (removed in 9.0)
476''''''''''''''''''''''''''''''''''''
477
478Use ``-run-with async-teardown=on`` instead.
479
480``-chroot`` (removed in 9.0)
481''''''''''''''''''''''''''''
482
483Use ``-run-with chroot=dir`` instead.
484
485``-singlestep`` (removed in 9.0)
486''''''''''''''''''''''''''''''''
487
488The ``-singlestep`` option has been turned into an accelerator property,
489and given a name that better reflects what it actually does.
490Use ``-accel tcg,one-insn-per-tb=on`` instead.
491
492``-smp`` ("parameter=0" SMP configurations) (removed in 9.0)
493''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
494
495Specified CPU topology parameters must be greater than zero.
496
497In the SMP configuration, users should either provide a CPU topology
498parameter with a reasonable value (greater than zero) or just omit it
499and QEMU will compute the missing value.
500
501However, historically it was implicitly allowed for users to provide
502a parameter with zero value, which is meaningless and could also possibly
503cause unexpected results in the -smp parsing. So support for this kind of
504configurations (e.g. -smp 8,sockets=0) is removed since 9.0, users have
505to ensure that all the topology members described with -smp are greater
506than zero.
507
508``-global migration.decompress-error-check`` (removed in 9.1)
509'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
510
511Removed along with the ``compression`` migration capability.
512
513``-device virtio-blk,scsi=on|off`` (removed in 9.1)
514'''''''''''''''''''''''''''''''''''''''''''''''''''
515
516The virtio-blk SCSI passthrough feature is a legacy VIRTIO feature.  VIRTIO 1.0
517and later do not support it because the virtio-scsi device was introduced for
518full SCSI support.  Use virtio-scsi instead when SCSI passthrough is required.
519
520``-fsdev proxy`` and ``-virtfs proxy`` (removed in 9.2)
521'''''''''''''''''''''''''''''''''''''''''''''''''''''''
522
523The 9p ``proxy`` filesystem backend driver was originally developed to
524enhance security by dispatching low level filesystem operations from 9p
525server (QEMU process) over to a separate process (the virtfs-proxy-helper
526binary). However the proxy backend was much slower than the local backend,
527didn't see any development in years, and showed to be less secure,
528especially due to the fact that its helper daemon must be run as root.
529
530Use ``local``, possibly mapping permissions et al by using its 'mapped'
531security model option, or switch to ``virtiofs``.   The virtiofs daemon
532``virtiofsd`` uses vhost to eliminate the high latency costs of the 9p
533``proxy`` backend.
534
535``-portrait`` and ``-rotate`` (removed in 9.2)
536''''''''''''''''''''''''''''''''''''''''''''''
537
538The ``-portrait`` and ``-rotate`` options were documented as only
539working with the PXA LCD device, and all the machine types using
540that display device were removed in 9.2, so these options also
541have been dropped.
542
543These options were intended to simulate a mobile device being
544rotated by the user, and had three effects:
545
546* the display output was rotated by 90, 180 or 270 degrees
547* the mouse/trackpad input was rotated the opposite way
548* the machine model would signal to the guest about its
549  orientation
550
551Of these three things, the input-rotation was coded without being
552restricted to boards which supported the full set of device-rotation
553handling, so in theory the options were usable on other machine models
554to produce an odd effect (rotating input but not display output). But
555this was never intended or documented behaviour, so we have dropped
556the options along with the machine models they were intended for.
557
558``-runas`` (removed in 10.0)
559''''''''''''''''''''''''''''
560
561Use ``-run-with user=..`` instead.
562
563
564User-mode emulator command line arguments
565-----------------------------------------
566
567``-singlestep`` (removed in 9.0)
568''''''''''''''''''''''''''''''''
569
570The ``-singlestep`` option has been given a name that better reflects
571what it actually does. For both linux-user and bsd-user, use the
572``-one-insn-per-tb`` option instead.
573
574
575QEMU Machine Protocol (QMP) commands
576------------------------------------
577
578``block-dirty-bitmap-add`` "autoload" parameter (removed in 4.2)
579''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
580
581The "autoload" parameter has been ignored since 2.12.0. All bitmaps
582are automatically loaded from qcow2 images.
583
584``cpu-add`` (removed in 5.2)
585''''''''''''''''''''''''''''
586
587Use ``device_add`` for hotplugging vCPUs instead of ``cpu-add``.  See
588documentation of ``query-hotpluggable-cpus`` for additional details.
589
590``change`` (removed in 6.0)
591'''''''''''''''''''''''''''
592
593Use ``blockdev-change-medium`` or ``change-vnc-password`` or
594``display-update`` instead.
595
596``query-events`` (removed in 6.0)
597'''''''''''''''''''''''''''''''''
598
599The ``query-events`` command has been superseded by the more powerful
600and accurate ``query-qmp-schema`` command.
601
602``migrate_set_cache_size`` and ``query-migrate-cache-size`` (removed in 6.0)
603''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
604
605Use ``migrate_set_parameter`` and ``info migrate_parameters`` instead.
606
607``migrate_set_downtime`` and ``migrate_set_speed`` (removed in 6.0)
608'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
609
610Use ``migrate_set_parameter`` instead.
611
612``query-cpus`` (removed in 6.0)
613'''''''''''''''''''''''''''''''
614
615The ``query-cpus`` command is replaced by the ``query-cpus-fast`` command.
616
617``query-cpus-fast`` ``arch`` output member (removed in 6.0)
618'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
619
620The ``arch`` output member of the ``query-cpus-fast`` command is
621replaced by the ``target`` output member.
622
623chardev client socket with ``wait`` option (removed in 6.0)
624'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
625
626Character devices creating sockets in client mode should not specify
627the 'wait' field, which is only applicable to sockets in server mode
628
629``query-named-block-nodes`` result ``encryption_key_missing`` (removed in 6.0)
630''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
631
632Removed with no replacement.
633
634``query-block`` result ``inserted.encryption_key_missing`` (removed in 6.0)
635'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
636
637Removed with no replacement.
638
639``query-named-block-nodes`` and ``query-block`` result dirty-bitmaps[i].status (removed in 6.0)
640'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
641
642The ``status`` field of the ``BlockDirtyInfo`` structure, returned by
643these commands is removed. Two new boolean fields, ``recording`` and
644``busy`` effectively replace it.
645
646``query-block`` result field ``dirty-bitmaps`` (removed in 6.0)
647'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
648
649The ``dirty-bitmaps`` field of the ``BlockInfo`` structure, returned by
650the query-block command is itself now removed. The ``dirty-bitmaps``
651field of the ``BlockDeviceInfo`` struct should be used instead, which is the
652type of the ``inserted`` field in query-block replies, as well as the
653type of array items in query-named-block-nodes.
654
655``object-add`` option ``props`` (removed in 6.0)
656''''''''''''''''''''''''''''''''''''''''''''''''
657
658Specify the properties for the object as top-level arguments instead.
659
660``query-sgx`` return value member ``section-size`` (removed in 8.0)
661'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
662
663Member ``section-size`` in the return value of ``query-sgx``
664was superseded by ``sections``.
665
666
667``query-sgx-capabilities`` return value member ``section-size`` (removed in 8.0)
668''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
669
670Member ``section-size`` in the return value of ``query-sgx-capabilities``
671was superseded by ``sections``.
672
673``query-migrate`` return value member ``skipped`` (removed in 9.1)
674''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
675
676Member ``skipped`` of the ``MigrationStats`` struct hasn't been used
677for more than 10 years. Removed with no replacement.
678
679``migrate`` command option ``inc`` (removed in 9.1)
680'''''''''''''''''''''''''''''''''''''''''''''''''''
681
682Use blockdev-mirror with NBD instead. See "QMP invocation for live
683storage migration with ``blockdev-mirror`` + NBD" in
684docs/interop/live-block-operations.rst for a detailed explanation.
685
686``migrate`` command option ``blk`` (removed in 9.1)
687'''''''''''''''''''''''''''''''''''''''''''''''''''
688
689Use blockdev-mirror with NBD instead. See "QMP invocation for live
690storage migration with ``blockdev-mirror`` + NBD" in
691docs/interop/live-block-operations.rst for a detailed explanation.
692
693``migrate-set-capabilities`` ``block`` option (removed in 9.1)
694''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
695
696Block migration has been removed. For a replacement, see "QMP
697invocation for live storage migration with ``blockdev-mirror`` + NBD"
698in docs/interop/live-block-operations.rst.
699
700``migrate-set-parameter`` ``compress-level`` option (removed in 9.1)
701''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
702
703Use ``multifd-zlib-level`` or ``multifd-zstd-level`` instead.
704
705``migrate-set-parameter`` ``compress-threads`` option (removed in 9.1)
706''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
707
708Use ``multifd-channels`` instead.
709
710``migrate-set-parameter`` ``compress-wait-thread`` option (removed in 9.1)
711''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
712
713Removed with no replacement.
714
715``migrate-set-parameter`` ``decompress-threads`` option (removed in 9.1)
716''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
717
718Use ``multifd-channels`` instead.
719
720``migrate-set-capability`` ``compress`` option (removed in 9.1)
721'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
722
723Use ``multifd-compression`` instead.
724
725QEMU Machine Protocol (QMP) events
726----------------------------------
727
728``MEM_UNPLUG_ERROR`` (removed in 9.1)
729'''''''''''''''''''''''''''''''''''''
730
731MEM_UNPLUG_ERROR has been replaced by the more generic ``DEVICE_UNPLUG_GUEST_ERROR`` event.
732
733``vcpu`` trace events (removed in 9.1)
734''''''''''''''''''''''''''''''''''''''
735
736The ability to instrument QEMU helper functions with vCPU-aware trace
737points was removed in 7.0.
738
739
740Human Monitor Protocol (HMP) commands
741-------------------------------------
742
743``usb_add`` and ``usb_remove`` (removed in 2.12)
744''''''''''''''''''''''''''''''''''''''''''''''''
745
746Replaced by ``device_add`` and ``device_del`` (use ``device_add help`` for a
747list of available devices).
748
749``host_net_add`` and ``host_net_remove`` (removed in 2.12)
750''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
751
752Replaced by ``netdev_add`` and ``netdev_del``.
753
754The ``hub_id`` parameter of ``hostfwd_add`` / ``hostfwd_remove`` (removed in 5.0)
755'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
756
757The ``[hub_id name]`` parameter tuple of the 'hostfwd_add' and
758'hostfwd_remove' HMP commands has been replaced by ``netdev_id``.
759
760``cpu-add`` (removed in 5.2)
761''''''''''''''''''''''''''''
762
763Use ``device_add`` for hotplugging vCPUs instead of ``cpu-add``.  See
764documentation of ``query-hotpluggable-cpus`` for additional details.
765
766``change vnc TARGET`` (removed in 6.0)
767''''''''''''''''''''''''''''''''''''''
768
769No replacement.  The ``change vnc password`` and ``change DEVICE MEDIUM``
770commands are not affected.
771
772``acl_show``, ``acl_reset``, ``acl_policy``, ``acl_add``, ``acl_remove`` (removed in 6.0)
773'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
774
775The ``acl_show``, ``acl_reset``, ``acl_policy``, ``acl_add``, and
776``acl_remove`` commands were removed with no replacement. Authorization
777for VNC should be performed using the pluggable QAuthZ objects.
778
779``migrate-set-cache-size`` and ``info migrate-cache-size`` (removed in 6.0)
780'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
781
782Use ``migrate-set-parameters`` and ``info migrate-parameters`` instead.
783
784``migrate_set_downtime`` and ``migrate_set_speed`` (removed in 6.0)
785'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
786
787Use ``migrate-set-parameters`` instead.
788
789``info cpustats`` (removed in 6.1)
790''''''''''''''''''''''''''''''''''
791
792This command didn't produce any output already. Removed with no replacement.
793
794``singlestep`` (removed in 9.0)
795'''''''''''''''''''''''''''''''
796
797The ``singlestep`` command has been replaced by the ``one-insn-per-tb``
798command, which has the same behaviour but a less misleading name.
799
800``migrate`` command ``-i`` option (removed in 9.1)
801''''''''''''''''''''''''''''''''''''''''''''''''''
802
803Use blockdev-mirror with NBD instead. See "QMP invocation for live
804storage migration with ``blockdev-mirror`` + NBD" in
805docs/interop/live-block-operations.rst for a detailed explanation.
806
807``migrate`` command ``-b`` option (removed in 9.1)
808''''''''''''''''''''''''''''''''''''''''''''''''''
809
810Use blockdev-mirror with NBD instead. See "QMP invocation for live
811storage migration with ``blockdev-mirror`` + NBD" in
812docs/interop/live-block-operations.rst for a detailed explanation.
813
814``migrate_set_capability`` ``block`` option (removed in 9.1)
815''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
816
817Block migration has been removed. For a replacement, see "QMP
818invocation for live storage migration with ``blockdev-mirror`` + NBD"
819in docs/interop/live-block-operations.rst.
820
821``migrate_set_parameter`` ``compress-level`` option (removed in 9.1)
822''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
823
824Use ``multifd-zlib-level`` or ``multifd-zstd-level`` instead.
825
826``migrate_set_parameter`` ``compress-threads`` option (removed in 9.1)
827''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
828
829Use ``multifd-channels`` instead.
830
831``migrate_set_parameter`` ``compress-wait-thread`` option (removed in 9.1)
832''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
833
834Removed with no replacement.
835
836``migrate_set_parameter`` ``decompress-threads`` option (removed in 9.1)
837''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
838
839Use ``multifd-channels`` instead.
840
841``migrate_set_capability`` ``compress`` option (removed in 9.1)
842'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
843
844Use ``multifd-compression`` instead.
845
846Host Architectures
847------------------
848
849System emulation on 32-bit Windows hosts (removed in 9.0)
850'''''''''''''''''''''''''''''''''''''''''''''''''''''''''
851
852Windows 11 has no support for 32-bit host installs, and Windows 10 did
853not support new 32-bit installs, only upgrades. 32-bit Windows support
854has now been dropped by the MSYS2 project. QEMU also is deprecating
855and dropping support for 32-bit x86 host deployments in
856general. 32-bit Windows is therefore no longer a supported host for
857QEMU.  Since all recent x86 hardware from the past >10 years is
858capable of the 64-bit x86 extensions, a corresponding 64-bit OS should
859be used instead.
860
861Guest Emulator ISAs
862-------------------
863
864RISC-V ISA privilege specification version 1.09.1 (removed in 5.1)
865''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
866
867The RISC-V ISA privilege specification version 1.09.1 has been removed.
868QEMU supports both the newer version 1.10.0 and the ratified version 1.11.0, these
869should be used instead of the 1.09.1 version.
870
871System emulator CPUS
872--------------------
873
874KVM guest support on 32-bit Arm hosts (removed in 5.2)
875''''''''''''''''''''''''''''''''''''''''''''''''''''''
876
877The Linux kernel has dropped support for allowing 32-bit Arm systems
878to host KVM guests as of the 5.7 kernel, and was thus removed from QEMU
879as well.  Running 32-bit guests on a 64-bit Arm host remains supported.
880
881RISC-V ISA Specific CPUs (removed in 5.1)
882'''''''''''''''''''''''''''''''''''''''''
883
884The RISC-V cpus with the ISA version in the CPU name have been removed. The
885four CPUs are: ``rv32gcsu-v1.9.1``, ``rv32gcsu-v1.10.0``, ``rv64gcsu-v1.9.1`` and
886``rv64gcsu-v1.10.0``. Instead the version can be specified via the CPU ``priv_spec``
887option when using the ``rv32`` or ``rv64`` CPUs.
888
889RISC-V no MMU CPUs (removed in 5.1)
890'''''''''''''''''''''''''''''''''''
891
892The RISC-V no MMU cpus have been removed. The two CPUs: ``rv32imacu-nommu`` and
893``rv64imacu-nommu`` can no longer be used. Instead the MMU status can be specified
894via the CPU ``mmu`` option when using the ``rv32`` or ``rv64`` CPUs.
895
896RISC-V 'any' CPU type ``-cpu any`` (removed in 9.2)
897'''''''''''''''''''''''''''''''''''''''''''''''''''
898
899The 'any' CPU type was introduced back in 2018 and was around since the
900initial RISC-V QEMU port. Its usage was always been unclear: users don't know
901what to expect from a CPU called 'any', and in fact the CPU does not do anything
902special that isn't already done by the default CPUs rv32/rv64.
903
904``compat`` property of server class POWER CPUs (removed in 6.0)
905'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
906
907The ``max-cpu-compat`` property of the ``pseries`` machine type should be used
908instead.
909
910``moxie`` CPU (removed in 6.1)
911''''''''''''''''''''''''''''''
912
913Nobody was using this CPU emulation in QEMU, and there were no test images
914available to make sure that the code is still working, so it has been removed
915without replacement.
916
917``lm32`` CPUs (removed in 6.1)
918''''''''''''''''''''''''''''''
919
920The only public user of this architecture was the milkymist project,
921which has been dead for years; there was never an upstream Linux
922port.  Removed without replacement.
923
924``unicore32`` CPUs (removed in 6.1)
925'''''''''''''''''''''''''''''''''''
926
927Support for this CPU was removed from the upstream Linux kernel, and
928there is no available upstream toolchain to build binaries for it.
929Removed without replacement.
930
931x86 ``Icelake-Client`` CPU (removed in 7.1)
932'''''''''''''''''''''''''''''''''''''''''''
933
934There isn't ever Icelake Client CPU, it is some wrong and imaginary one.
935Use ``Icelake-Server`` instead.
936
937Nios II CPU (removed in 9.1)
938''''''''''''''''''''''''''''
939
940QEMU Nios II architecture was orphan; Intel has EOL'ed the Nios II
941processor IP (see `Intel discontinuance notification`_).
942
943CRIS CPU architecture (removed in 9.2)
944''''''''''''''''''''''''''''''''''''''
945
946The CRIS architecture was pulled from Linux in 4.17 and the compiler
947was no longer packaged in any distro making it harder to run the
948``check-tcg`` tests.
949
950System accelerators
951-------------------
952
953Userspace local APIC with KVM (x86, removed in 8.0)
954'''''''''''''''''''''''''''''''''''''''''''''''''''
955
956``-M kernel-irqchip=off`` cannot be used on KVM if the CPU model includes
957a local APIC.  The ``split`` setting is supported, as is using ``-M
958kernel-irqchip=off`` when the CPU does not have a local APIC.
959
960HAXM (``-accel hax``) (removed in 8.2)
961''''''''''''''''''''''''''''''''''''''
962
963The HAXM project has been retired (see https://github.com/intel/haxm#status).
964Use "whpx" (on Windows) or "hvf" (on macOS) instead.
965
966MIPS "Trap-and-Emulate" KVM support (removed in 8.0)
967''''''''''''''''''''''''''''''''''''''''''''''''''''
968
969The MIPS "Trap-and-Emulate" KVM host and guest support was removed
970from Linux in 2021, and is not supported anymore by QEMU either.
971
972System emulator machines
973------------------------
974
975``s390-virtio`` (removed in 2.6)
976''''''''''''''''''''''''''''''''
977
978Use the ``s390-ccw-virtio`` machine instead.
979
980The m68k ``dummy`` machine (removed in 2.9)
981'''''''''''''''''''''''''''''''''''''''''''
982
983Use the ``none`` machine with the ``loader`` device instead.
984
985``xlnx-ep108`` (removed in 3.0)
986'''''''''''''''''''''''''''''''
987
988The EP108 was an early access development board that is no longer used.
989Use the ``xlnx-zcu102`` machine instead.
990
991``spike_v1.9.1`` and ``spike_v1.10`` (removed in 5.1)
992'''''''''''''''''''''''''''''''''''''''''''''''''''''
993
994The version specific Spike machines have been removed in favour of the
995generic ``spike`` machine. If you need to specify an older version of the RISC-V
996spec you can use the ``-cpu rv64gcsu,priv_spec=v1.10.0`` command line argument.
997
998mips ``r4k`` platform (removed in 5.2)
999''''''''''''''''''''''''''''''''''''''
1000
1001This machine type was very old and unmaintained. Users should use the ``malta``
1002machine type instead.
1003
1004mips ``fulong2e`` machine alias (removed in 6.0)
1005''''''''''''''''''''''''''''''''''''''''''''''''
1006
1007This machine has been renamed ``fuloong2e``.
1008
1009``pc-0.10`` up to ``pc-i440fx-2.3`` (removed in 4.0 up to 9.0)
1010''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1011
1012These machine types were very old and likely could not be used for live
1013migration from old QEMU versions anymore. Use a newer machine type instead.
1014
1015Raspberry Pi ``raspi2`` and ``raspi3`` machines (removed in 6.2)
1016''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1017
1018The Raspberry Pi machines come in various models (A, A+, B, B+). To be able
1019to distinguish which model QEMU is implementing, the ``raspi2`` and ``raspi3``
1020machines have been renamed ``raspi2b`` and ``raspi3b``.
1021
1022Aspeed ``swift-bmc`` machine (removed in 7.0)
1023'''''''''''''''''''''''''''''''''''''''''''''
1024
1025This machine was removed because it was unused. Alternative AST2500 based
1026OpenPOWER machines are ``witherspoon-bmc`` and ``romulus-bmc``.
1027
1028Aspeed ``tacoma-bmc`` machine (removed in 10.0)
1029'''''''''''''''''''''''''''''''''''''''''''''''
1030
1031The ``tacoma-bmc`` machine was removed because it didn't bring much
1032compared to the ``rainier-bmc`` machine. Also, the ``tacoma-bmc`` was
1033a board used for bring up of the AST2600 SoC that never left the
1034labs. It can be easily replaced by the ``rainier-bmc`` machine, which
1035was the actual final product, or by the ``ast2600-evb`` with some
1036tweaks.
1037
1038ppc ``taihu`` machine (removed in 7.2)
1039'''''''''''''''''''''''''''''''''''''''''''''
1040
1041This machine was removed because it was partially emulated and 405
1042machines are very similar. Use the ``ref405ep`` machine instead.
1043
1044Nios II ``10m50-ghrd`` and ``nios2-generic-nommu`` machines (removed in 9.1)
1045''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1046
1047The Nios II architecture was orphan.
1048
1049``shix`` (removed in 9.2)
1050'''''''''''''''''''''''''
1051
1052The machine was unmaintained.
1053
1054Arm machines ``akita``, ``borzoi``, ``cheetah``, ``connex``, ``mainstone``, ``n800``, ``n810``, ``spitz``, ``terrier``, ``tosa``, ``verdex``, ``z2`` (removed in 9.2)
1055'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1056
1057QEMU included models of some machine types where the QEMU code that
1058emulates their SoCs was very old and unmaintained. This code was
1059blocking our ability to move forward with various changes across
1060the codebase, and over many years nobody has been interested in
1061trying to modernise it. We don't expect any of these machines to have
1062a large number of users, because they're all modelling hardware that
1063has now passed away into history. We are therefore dropping support
1064for all machine types using the PXA2xx and OMAP2 SoCs. We are also
1065dropping the ``cheetah`` OMAP1 board, because we don't have any
1066test images for it and don't know of anybody who does.
1067
1068linux-user mode CPUs
1069--------------------
1070
1071``tilegx`` CPUs (removed in 6.0)
1072''''''''''''''''''''''''''''''''
1073
1074The ``tilegx`` guest CPU support has been removed without replacement. It was
1075only implemented in linux-user mode, but support for this CPU was removed from
1076the upstream Linux kernel in 2018, and it has also been dropped from glibc, so
1077there is no new Linux development taking place with this architecture. For
1078running the old binaries, you can use older versions of QEMU.
1079
1080``ppc64abi32`` CPUs (removed in 7.0)
1081''''''''''''''''''''''''''''''''''''
1082
1083The ``ppc64abi32`` architecture has a number of issues which regularly
1084tripped up the CI testing and was suspected to be quite broken. For that
1085reason the maintainers strongly suspected no one actually used it.
1086
1087``nios2`` CPU (removed in 9.1)
1088''''''''''''''''''''''''''''''
1089
1090QEMU Nios II architecture was orphan; Intel has EOL'ed the Nios II
1091processor IP (see `Intel discontinuance notification`_).
1092
1093TCG introspection features
1094--------------------------
1095
1096TCG trace-events (removed in 7.0)
1097'''''''''''''''''''''''''''''''''
1098
1099The ability to add new TCG trace points had bit rotted and as the
1100feature can be replicated with TCG plugins it was removed. If
1101any user is currently using this feature and needs help with
1102converting to using TCG plugins they should contact the qemu-devel
1103mailing list.
1104
1105
1106System emulator devices
1107-----------------------
1108
1109``spapr-pci-vfio-host-bridge`` (removed in 2.12)
1110'''''''''''''''''''''''''''''''''''''''''''''''''
1111
1112The ``spapr-pci-vfio-host-bridge`` device type has been replaced by the
1113``spapr-pci-host-bridge`` device type.
1114
1115``ivshmem`` (removed in 4.0)
1116''''''''''''''''''''''''''''
1117
1118Replaced by either the ``ivshmem-plain`` or ``ivshmem-doorbell``.
1119
1120``ide-drive`` (removed in 6.0)
1121''''''''''''''''''''''''''''''
1122
1123The 'ide-drive' device has been removed. Users should use 'ide-hd' or
1124'ide-cd' as appropriate to get an IDE hard disk or CD-ROM as needed.
1125
1126``scsi-disk`` (removed in 6.0)
1127''''''''''''''''''''''''''''''
1128
1129The 'scsi-disk' device has been removed. Users should use 'scsi-hd' or
1130'scsi-cd' as appropriate to get a SCSI hard disk or CD-ROM as needed.
1131
1132``sga`` (removed in 8.0)
1133''''''''''''''''''''''''
1134
1135The ``sga`` device loaded an option ROM for x86 targets which enabled
1136SeaBIOS to send messages to the serial console. SeaBIOS 1.11.0 onwards
1137contains native support for this feature and thus use of the option
1138ROM approach was obsolete. The native SeaBIOS support can be activated
1139by using ``-machine graphics=off``.
1140
1141``pvrdma`` and the RDMA subsystem (removed in 9.1)
1142''''''''''''''''''''''''''''''''''''''''''''''''''
1143
1144The 'pvrdma' device and the whole RDMA subsystem have been removed.
1145
1146Related binaries
1147----------------
1148
1149``qemu-nbd --partition`` (removed in 5.0)
1150'''''''''''''''''''''''''''''''''''''''''
1151
1152The ``qemu-nbd --partition $digit`` code (also spelled ``-P``)
1153could only handle MBR partitions, and never correctly handled logical
1154partitions beyond partition 5.  Exporting a partition can still be
1155done by utilizing the ``--image-opts`` option with a raw blockdev
1156using the ``offset`` and ``size`` parameters layered on top of
1157any other existing blockdev. For example, if partition 1 is 100MiB
1158long starting at 1MiB, the old command::
1159
1160  qemu-nbd -t -P 1 -f qcow2 file.qcow2
1161
1162can be rewritten as::
1163
1164  qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.file.driver=file,file.file.filename=file.qcow2
1165
1166``qemu-img convert -n -o`` (removed in 5.1)
1167'''''''''''''''''''''''''''''''''''''''''''
1168
1169All options specified in ``-o`` are image creation options, so
1170they are now rejected when used with ``-n`` to skip image creation.
1171
1172
1173``qemu-img create -b bad file $size`` (removed in 5.1)
1174''''''''''''''''''''''''''''''''''''''''''''''''''''''
1175
1176When creating an image with a backing file that could not be opened,
1177``qemu-img create`` used to issue a warning about the failure but
1178proceed with the image creation if an explicit size was provided.
1179However, as the ``-u`` option exists for this purpose, it is safer to
1180enforce that any failure to open the backing image (including if the
1181backing file is missing or an incorrect format was specified) is an
1182error when ``-u`` is not used.
1183
1184``qemu-img amend`` to adjust backing file (removed in 6.1)
1185''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1186
1187The use of ``qemu-img amend`` to modify the name or format of a qcow2
1188backing image was never fully documented or tested, and interferes
1189with other amend operations that need access to the original backing
1190image (such as deciding whether a v3 zero cluster may be left
1191unallocated when converting to a v2 image).  Any changes to the
1192backing chain should be performed with ``qemu-img rebase -u`` either
1193before or after the remaining changes being performed by amend, as
1194appropriate.
1195
1196``qemu-img`` backing file without format (removed in 6.1)
1197'''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1198
1199The use of ``qemu-img create``, ``qemu-img rebase``, or ``qemu-img
1200convert`` to create or modify an image that depends on a backing file
1201now requires that an explicit backing format be provided.  This is
1202for safety: if QEMU probes a different format than what you thought,
1203the data presented to the guest will be corrupt; similarly, presenting
1204a raw image to a guest allows a potential security exploit if a future
1205probe sees a non-raw image based on guest writes.
1206
1207To avoid creating unsafe backing chains, you must pass ``-o
1208backing_fmt=`` (or the shorthand ``-F`` during create) to specify the
1209intended backing format.  You may use ``qemu-img rebase -u`` to
1210retroactively add a backing format to an existing image.  However, be
1211aware that there are already potential security risks to blindly using
1212``qemu-img info`` to probe the format of an untrusted backing image,
1213when deciding what format to add into an existing image.
1214
1215Block devices
1216-------------
1217
1218VXHS backend (removed in 5.1)
1219'''''''''''''''''''''''''''''
1220
1221The VXHS code did not compile since v2.12.0. It was removed in 5.1.
1222
1223``sheepdog`` driver (removed in 6.0)
1224''''''''''''''''''''''''''''''''''''
1225
1226The corresponding upstream server project is no longer maintained.
1227Users are recommended to switch to an alternative distributed block
1228device driver such as RBD.
1229
1230Tools
1231-----
1232
1233virtiofsd (removed in 8.0)
1234''''''''''''''''''''''''''
1235
1236There is a newer Rust implementation of ``virtiofsd`` at
1237``https://gitlab.com/virtio-fs/virtiofsd``; this has been
1238stable for some time and is now widely used.
1239The command line and feature set is very close to the removed
1240C implementation.
1241
1242QEMU guest agent
1243----------------
1244
1245``--blacklist`` command line option (removed in 9.1)
1246''''''''''''''''''''''''''''''''''''''''''''''''''''
1247
1248``--blacklist`` has been replaced by ``--block-rpcs`` (which is a better
1249wording for what this option does). The short form ``-b`` still stays
1250the same and thus is the preferred way for scripts that should run with
1251both, older and future versions of QEMU.
1252
1253``blacklist`` config file option (removed in 9.1)
1254'''''''''''''''''''''''''''''''''''''''''''''''''
1255
1256The ``blacklist`` config file option has been renamed to ``block-rpcs``
1257(to be in sync with the renaming of the corresponding command line
1258option).
1259
1260.. _Intel discontinuance notification: https://www.intel.com/content/www/us/en/content-details/781327/intel-is-discontinuing-ip-ordering-codes-listed-in-pdn2312-for-nios-ii-ip.html
1261