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22This option has been replaced by ``-net user,guestfwd=...``.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27``-net dump[,vlan=n][,file=filename][,len=maxlen]`` has been replaced by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 ``secret_keyring`` objects (removed in 7.1)
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 should simply be 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`` (since 7.2)
407'''''''''''''''''''''''''
408
409Use ``-device`` instead.
410
411Hexadecimal sizes with scaling multipliers (since 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`` (since 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`` (since 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`` (since 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
558User-mode emulator command line arguments
559-----------------------------------------
560
561``-singlestep`` (removed in 9.0)
562''''''''''''''''''''''''''''''''
563
564The ``-singlestep`` option has been given a name that better reflects
565what it actually does. For both linux-user and bsd-user, use the
566``-one-insn-per-tb`` option instead.
567
568
569QEMU Machine Protocol (QMP) commands
570------------------------------------
571
572``block-dirty-bitmap-add`` "autoload" parameter (removed in 4.2)
573''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
574
575The "autoload" parameter has been ignored since 2.12.0. All bitmaps
576are automatically loaded from qcow2 images.
577
578``cpu-add`` (removed in 5.2)
579''''''''''''''''''''''''''''
580
581Use ``device_add`` for hotplugging vCPUs instead of ``cpu-add``.  See
582documentation of ``query-hotpluggable-cpus`` for additional details.
583
584``change`` (removed in 6.0)
585'''''''''''''''''''''''''''
586
587Use ``blockdev-change-medium`` or ``change-vnc-password`` or
588``display-update`` instead.
589
590``query-events`` (removed in 6.0)
591'''''''''''''''''''''''''''''''''
592
593The ``query-events`` command has been superseded by the more powerful
594and accurate ``query-qmp-schema`` command.
595
596``migrate_set_cache_size`` and ``query-migrate-cache-size`` (removed in 6.0)
597''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
598
599Use ``migrate_set_parameter`` and ``info migrate_parameters`` instead.
600
601``migrate_set_downtime`` and ``migrate_set_speed`` (removed in 6.0)
602'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
603
604Use ``migrate_set_parameter`` instead.
605
606``query-cpus`` (removed in 6.0)
607'''''''''''''''''''''''''''''''
608
609The ``query-cpus`` command is replaced by the ``query-cpus-fast`` command.
610
611``query-cpus-fast`` ``arch`` output member (removed in 6.0)
612'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
613
614The ``arch`` output member of the ``query-cpus-fast`` command is
615replaced by the ``target`` output member.
616
617chardev client socket with ``wait`` option (removed in 6.0)
618'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
619
620Character devices creating sockets in client mode should not specify
621the 'wait' field, which is only applicable to sockets in server mode
622
623``query-named-block-nodes`` result ``encryption_key_missing`` (removed in 6.0)
624''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
625
626Removed with no replacement.
627
628``query-block`` result ``inserted.encryption_key_missing`` (removed in 6.0)
629'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
630
631Removed with no replacement.
632
633``query-named-block-nodes`` and ``query-block`` result dirty-bitmaps[i].status (removed in 6.0)
634'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
635
636The ``status`` field of the ``BlockDirtyInfo`` structure, returned by
637these commands is removed. Two new boolean fields, ``recording`` and
638``busy`` effectively replace it.
639
640``query-block`` result field ``dirty-bitmaps`` (removed in 6.0)
641'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
642
643The ``dirty-bitmaps`` field of the ``BlockInfo`` structure, returned by
644the query-block command is itself now removed. The ``dirty-bitmaps``
645field of the ``BlockDeviceInfo`` struct should be used instead, which is the
646type of the ``inserted`` field in query-block replies, as well as the
647type of array items in query-named-block-nodes.
648
649``object-add`` option ``props`` (removed in 6.0)
650''''''''''''''''''''''''''''''''''''''''''''''''
651
652Specify the properties for the object as top-level arguments instead.
653
654``query-sgx`` return value member ``section-size`` (removed in 8.0)
655'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
656
657Member ``section-size`` in the return value of ``query-sgx``
658was superseded by ``sections``.
659
660
661``query-sgx-capabilities`` return value member ``section-size`` (removed in 8.0)
662''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
663
664Member ``section-size`` in the return value of ``query-sgx-capabilities``
665was superseded by ``sections``.
666
667``query-migrate`` return value member ``skipped`` (removed in 9.1)
668''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
669
670Member ``skipped`` of the ``MigrationStats`` struct hasn't been used
671for more than 10 years. Removed with no replacement.
672
673``migrate`` command option ``inc`` (removed in 9.1)
674'''''''''''''''''''''''''''''''''''''''''''''''''''
675
676Use blockdev-mirror with NBD instead. See "QMP invocation for live
677storage migration with ``blockdev-mirror`` + NBD" in
678docs/interop/live-block-operations.rst for a detailed explanation.
679
680``migrate`` command option ``blk`` (removed in 9.1)
681'''''''''''''''''''''''''''''''''''''''''''''''''''
682
683Use blockdev-mirror with NBD instead. See "QMP invocation for live
684storage migration with ``blockdev-mirror`` + NBD" in
685docs/interop/live-block-operations.rst for a detailed explanation.
686
687``migrate-set-capabilities`` ``block`` option (removed in 9.1)
688''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
689
690Block migration has been removed. For a replacement, see "QMP
691invocation for live storage migration with ``blockdev-mirror`` + NBD"
692in docs/interop/live-block-operations.rst.
693
694``migrate-set-parameter`` ``compress-level`` option (removed in 9.1)
695''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
696
697Use ``multifd-zlib-level`` or ``multifd-zstd-level`` instead.
698
699``migrate-set-parameter`` ``compress-threads`` option (removed in 9.1)
700''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
701
702Use ``multifd-channels`` instead.
703
704``migrate-set-parameter`` ``compress-wait-thread`` option (removed in 9.1)
705''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
706
707Removed with no replacement.
708
709``migrate-set-parameter`` ``decompress-threads`` option (removed in 9.1)
710''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
711
712Use ``multifd-channels`` instead.
713
714``migrate-set-capability`` ``compress`` option (removed in 9.1)
715'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
716
717Use ``multifd-compression`` instead.
718
719QEMU Machine Protocol (QMP) events
720----------------------------------
721
722``MEM_UNPLUG_ERROR`` (removed in 9.1)
723'''''''''''''''''''''''''''''''''''''
724
725MEM_UNPLUG_ERROR has been replaced by the more generic ``DEVICE_UNPLUG_GUEST_ERROR`` event.
726
727``vcpu`` trace events (removed in 9.1)
728''''''''''''''''''''''''''''''''''''''
729
730The ability to instrument QEMU helper functions with vCPU-aware trace
731points was removed in 7.0.
732
733
734Human Monitor Protocol (HMP) commands
735-------------------------------------
736
737``usb_add`` and ``usb_remove`` (removed in 2.12)
738''''''''''''''''''''''''''''''''''''''''''''''''
739
740Replaced by ``device_add`` and ``device_del`` (use ``device_add help`` for a
741list of available devices).
742
743``host_net_add`` and ``host_net_remove`` (removed in 2.12)
744''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
745
746Replaced by ``netdev_add`` and ``netdev_del``.
747
748The ``hub_id`` parameter of ``hostfwd_add`` / ``hostfwd_remove`` (removed in 5.0)
749'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
750
751The ``[hub_id name]`` parameter tuple of the 'hostfwd_add' and
752'hostfwd_remove' HMP commands has been replaced by ``netdev_id``.
753
754``cpu-add`` (removed in 5.2)
755''''''''''''''''''''''''''''
756
757Use ``device_add`` for hotplugging vCPUs instead of ``cpu-add``.  See
758documentation of ``query-hotpluggable-cpus`` for additional details.
759
760``change vnc TARGET`` (removed in 6.0)
761''''''''''''''''''''''''''''''''''''''
762
763No replacement.  The ``change vnc password`` and ``change DEVICE MEDIUM``
764commands are not affected.
765
766``acl_show``, ``acl_reset``, ``acl_policy``, ``acl_add``, ``acl_remove`` (removed in 6.0)
767'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
768
769The ``acl_show``, ``acl_reset``, ``acl_policy``, ``acl_add``, and
770``acl_remove`` commands were removed with no replacement. Authorization
771for VNC should be performed using the pluggable QAuthZ objects.
772
773``migrate-set-cache-size`` and ``info migrate-cache-size`` (removed in 6.0)
774'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
775
776Use ``migrate-set-parameters`` and ``info migrate-parameters`` instead.
777
778``migrate_set_downtime`` and ``migrate_set_speed`` (removed in 6.0)
779'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
780
781Use ``migrate-set-parameters`` instead.
782
783``info cpustats`` (removed in 6.1)
784''''''''''''''''''''''''''''''''''
785
786This command didn't produce any output already. Removed with no replacement.
787
788``singlestep`` (removed in 9.0)
789'''''''''''''''''''''''''''''''
790
791The ``singlestep`` command has been replaced by the ``one-insn-per-tb``
792command, which has the same behaviour but a less misleading name.
793
794``migrate`` command ``-i`` option (removed in 9.1)
795''''''''''''''''''''''''''''''''''''''''''''''''''
796
797Use blockdev-mirror with NBD instead. See "QMP invocation for live
798storage migration with ``blockdev-mirror`` + NBD" in
799docs/interop/live-block-operations.rst for a detailed explanation.
800
801``migrate`` command ``-b`` option (removed in 9.1)
802''''''''''''''''''''''''''''''''''''''''''''''''''
803
804Use blockdev-mirror with NBD instead. See "QMP invocation for live
805storage migration with ``blockdev-mirror`` + NBD" in
806docs/interop/live-block-operations.rst for a detailed explanation.
807
808``migrate_set_capability`` ``block`` option (removed in 9.1)
809''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
810
811Block migration has been removed. For a replacement, see "QMP
812invocation for live storage migration with ``blockdev-mirror`` + NBD"
813in docs/interop/live-block-operations.rst.
814
815``migrate_set_parameter`` ``compress-level`` option (removed in 9.1)
816''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
817
818Use ``multifd-zlib-level`` or ``multifd-zstd-level`` instead.
819
820``migrate_set_parameter`` ``compress-threads`` option (removed in 9.1)
821''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
822
823Use ``multifd-channels`` instead.
824
825``migrate_set_parameter`` ``compress-wait-thread`` option (removed in 9.1)
826''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
827
828Removed with no replacement.
829
830``migrate_set_parameter`` ``decompress-threads`` option (removed in 9.1)
831''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
832
833Use ``multifd-channels`` instead.
834
835``migrate_set_capability`` ``compress`` option (removed in 9.1)
836'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
837
838Use ``multifd-compression`` instead.
839
840Host Architectures
841------------------
842
843System emulation on 32-bit Windows hosts (removed in 9.0)
844'''''''''''''''''''''''''''''''''''''''''''''''''''''''''
845
846Windows 11 has no support for 32-bit host installs, and Windows 10 did
847not support new 32-bit installs, only upgrades. 32-bit Windows support
848has now been dropped by the MSYS2 project. QEMU also is deprecating
849and dropping support for 32-bit x86 host deployments in
850general. 32-bit Windows is therefore no longer a supported host for
851QEMU.  Since all recent x86 hardware from the past >10 years is
852capable of the 64-bit x86 extensions, a corresponding 64-bit OS should
853be used instead.
854
855Guest Emulator ISAs
856-------------------
857
858RISC-V ISA privilege specification version 1.09.1 (removed in 5.1)
859''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
860
861The RISC-V ISA privilege specification version 1.09.1 has been removed.
862QEMU supports both the newer version 1.10.0 and the ratified version 1.11.0, these
863should be used instead of the 1.09.1 version.
864
865System emulator CPUS
866--------------------
867
868KVM guest support on 32-bit Arm hosts (removed in 5.2)
869''''''''''''''''''''''''''''''''''''''''''''''''''''''
870
871The Linux kernel has dropped support for allowing 32-bit Arm systems
872to host KVM guests as of the 5.7 kernel, and was thus removed from QEMU
873as well.  Running 32-bit guests on a 64-bit Arm host remains supported.
874
875RISC-V ISA Specific CPUs (removed in 5.1)
876'''''''''''''''''''''''''''''''''''''''''
877
878The RISC-V cpus with the ISA version in the CPU name have been removed. The
879four CPUs are: ``rv32gcsu-v1.9.1``, ``rv32gcsu-v1.10.0``, ``rv64gcsu-v1.9.1`` and
880``rv64gcsu-v1.10.0``. Instead the version can be specified via the CPU ``priv_spec``
881option when using the ``rv32`` or ``rv64`` CPUs.
882
883RISC-V no MMU CPUs (removed in 5.1)
884'''''''''''''''''''''''''''''''''''
885
886The RISC-V no MMU cpus have been removed. The two CPUs: ``rv32imacu-nommu`` and
887``rv64imacu-nommu`` can no longer be used. Instead the MMU status can be specified
888via the CPU ``mmu`` option when using the ``rv32`` or ``rv64`` CPUs.
889
890RISC-V 'any' CPU type ``-cpu any`` (removed in 9.2)
891'''''''''''''''''''''''''''''''''''''''''''''''''''
892
893The 'any' CPU type was introduced back in 2018 and was around since the
894initial RISC-V QEMU port. Its usage was always been unclear: users don't know
895what to expect from a CPU called 'any', and in fact the CPU does not do anything
896special that isn't already done by the default CPUs rv32/rv64.
897
898``compat`` property of server class POWER CPUs (removed in 6.0)
899'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
900
901The ``max-cpu-compat`` property of the ``pseries`` machine type should be used
902instead.
903
904``moxie`` CPU (removed in 6.1)
905''''''''''''''''''''''''''''''
906
907Nobody was using this CPU emulation in QEMU, and there were no test images
908available to make sure that the code is still working, so it has been removed
909without replacement.
910
911``lm32`` CPUs (removed in 6.1)
912''''''''''''''''''''''''''''''
913
914The only public user of this architecture was the milkymist project,
915which has been dead for years; there was never an upstream Linux
916port.  Removed without replacement.
917
918``unicore32`` CPUs (removed in 6.1)
919'''''''''''''''''''''''''''''''''''
920
921Support for this CPU was removed from the upstream Linux kernel, and
922there is no available upstream toolchain to build binaries for it.
923Removed without replacement.
924
925x86 ``Icelake-Client`` CPU (removed in 7.1)
926'''''''''''''''''''''''''''''''''''''''''''
927
928There isn't ever Icelake Client CPU, it is some wrong and imaginary one.
929Use ``Icelake-Server`` instead.
930
931Nios II CPU (removed in 9.1)
932''''''''''''''''''''''''''''
933
934QEMU Nios II architecture was orphan; Intel has EOL'ed the Nios II
935processor IP (see `Intel discontinuance notification`_).
936
937CRIS CPU architecture (removed in 9.2)
938''''''''''''''''''''''''''''''''''''''
939
940The CRIS architecture was pulled from Linux in 4.17 and the compiler
941was no longer packaged in any distro making it harder to run the
942``check-tcg`` tests.
943
944System accelerators
945-------------------
946
947Userspace local APIC with KVM (x86, removed in 8.0)
948'''''''''''''''''''''''''''''''''''''''''''''''''''
949
950``-M kernel-irqchip=off`` cannot be used on KVM if the CPU model includes
951a local APIC.  The ``split`` setting is supported, as is using ``-M
952kernel-irqchip=off`` when the CPU does not have a local APIC.
953
954HAXM (``-accel hax``) (removed in 8.2)
955''''''''''''''''''''''''''''''''''''''
956
957The HAXM project has been retired (see https://github.com/intel/haxm#status).
958Use "whpx" (on Windows) or "hvf" (on macOS) instead.
959
960MIPS "Trap-and-Emulate" KVM support (removed in 8.0)
961''''''''''''''''''''''''''''''''''''''''''''''''''''
962
963The MIPS "Trap-and-Emulate" KVM host and guest support was removed
964from Linux in 2021, and is not supported anymore by QEMU either.
965
966System emulator machines
967------------------------
968
969``s390-virtio`` (removed in 2.6)
970''''''''''''''''''''''''''''''''
971
972Use the ``s390-ccw-virtio`` machine instead.
973
974The m68k ``dummy`` machine (removed in 2.9)
975'''''''''''''''''''''''''''''''''''''''''''
976
977Use the ``none`` machine with the ``loader`` device instead.
978
979``xlnx-ep108`` (removed in 3.0)
980'''''''''''''''''''''''''''''''
981
982The EP108 was an early access development board that is no longer used.
983Use the ``xlnx-zcu102`` machine instead.
984
985``spike_v1.9.1`` and ``spike_v1.10`` (removed in 5.1)
986'''''''''''''''''''''''''''''''''''''''''''''''''''''
987
988The version specific Spike machines have been removed in favour of the
989generic ``spike`` machine. If you need to specify an older version of the RISC-V
990spec you can use the ``-cpu rv64gcsu,priv_spec=v1.10.0`` command line argument.
991
992mips ``r4k`` platform (removed in 5.2)
993''''''''''''''''''''''''''''''''''''''
994
995This machine type was very old and unmaintained. Users should use the ``malta``
996machine type instead.
997
998mips ``fulong2e`` machine alias (removed in 6.0)
999''''''''''''''''''''''''''''''''''''''''''''''''
1000
1001This machine has been renamed ``fuloong2e``.
1002
1003``pc-0.10`` up to ``pc-i440fx-2.3`` (removed in 4.0 up to 9.0)
1004''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1005
1006These machine types were very old and likely could not be used for live
1007migration from old QEMU versions anymore. Use a newer machine type instead.
1008
1009Raspberry Pi ``raspi2`` and ``raspi3`` machines (removed in 6.2)
1010''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1011
1012The Raspberry Pi machines come in various models (A, A+, B, B+). To be able
1013to distinguish which model QEMU is implementing, the ``raspi2`` and ``raspi3``
1014machines have been renamed ``raspi2b`` and ``raspi3b``.
1015
1016Aspeed ``swift-bmc`` machine (removed in 7.0)
1017'''''''''''''''''''''''''''''''''''''''''''''
1018
1019This machine was removed because it was unused. Alternative AST2500 based
1020OpenPOWER machines are ``witherspoon-bmc`` and ``romulus-bmc``.
1021
1022ppc ``taihu`` machine (removed in 7.2)
1023'''''''''''''''''''''''''''''''''''''''''''''
1024
1025This machine was removed because it was partially emulated and 405
1026machines are very similar. Use the ``ref405ep`` machine instead.
1027
1028Nios II ``10m50-ghrd`` and ``nios2-generic-nommu`` machines (removed in 9.1)
1029''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1030
1031The Nios II architecture was orphan.
1032
1033``shix`` (removed in 9.2)
1034'''''''''''''''''''''''''
1035
1036The machine was unmaintained.
1037
1038Arm machines ``akita``, ``borzoi``, ``cheetah``, ``connex``, ``mainstone``, ``n800``, ``n810``, ``spitz``, ``terrier``, ``tosa``, ``verdex``, ``z2`` (removed in 9.2)
1039'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1040
1041QEMU included models of some machine types where the QEMU code that
1042emulates their SoCs was very old and unmaintained. This code was
1043blocking our ability to move forward with various changes across
1044the codebase, and over many years nobody has been interested in
1045trying to modernise it. We don't expect any of these machines to have
1046a large number of users, because they're all modelling hardware that
1047has now passed away into history. We are therefore dropping support
1048for all machine types using the PXA2xx and OMAP2 SoCs. We are also
1049dropping the ``cheetah`` OMAP1 board, because we don't have any
1050test images for it and don't know of anybody who does.
1051
1052linux-user mode CPUs
1053--------------------
1054
1055``tilegx`` CPUs (removed in 6.0)
1056''''''''''''''''''''''''''''''''
1057
1058The ``tilegx`` guest CPU support has been removed without replacement. It was
1059only implemented in linux-user mode, but support for this CPU was removed from
1060the upstream Linux kernel in 2018, and it has also been dropped from glibc, so
1061there is no new Linux development taking place with this architecture. For
1062running the old binaries, you can use older versions of QEMU.
1063
1064``ppc64abi32`` CPUs (removed in 7.0)
1065''''''''''''''''''''''''''''''''''''
1066
1067The ``ppc64abi32`` architecture has a number of issues which regularly
1068tripped up the CI testing and was suspected to be quite broken. For that
1069reason the maintainers strongly suspected no one actually used it.
1070
1071``nios2`` CPU (removed in 9.1)
1072''''''''''''''''''''''''''''''
1073
1074QEMU Nios II architecture was orphan; Intel has EOL'ed the Nios II
1075processor IP (see `Intel discontinuance notification`_).
1076
1077TCG introspection features
1078--------------------------
1079
1080TCG trace-events (since 6.2)
1081''''''''''''''''''''''''''''
1082
1083The ability to add new TCG trace points had bit rotted and as the
1084feature can be replicated with TCG plugins it was removed. If
1085any user is currently using this feature and needs help with
1086converting to using TCG plugins they should contact the qemu-devel
1087mailing list.
1088
1089
1090System emulator devices
1091-----------------------
1092
1093``spapr-pci-vfio-host-bridge`` (removed in 2.12)
1094'''''''''''''''''''''''''''''''''''''''''''''''''
1095
1096The ``spapr-pci-vfio-host-bridge`` device type has been replaced by the
1097``spapr-pci-host-bridge`` device type.
1098
1099``ivshmem`` (removed in 4.0)
1100''''''''''''''''''''''''''''
1101
1102Replaced by either the ``ivshmem-plain`` or ``ivshmem-doorbell``.
1103
1104``ide-drive`` (removed in 6.0)
1105''''''''''''''''''''''''''''''
1106
1107The 'ide-drive' device has been removed. Users should use 'ide-hd' or
1108'ide-cd' as appropriate to get an IDE hard disk or CD-ROM as needed.
1109
1110``scsi-disk`` (removed in 6.0)
1111''''''''''''''''''''''''''''''
1112
1113The 'scsi-disk' device has been removed. Users should use 'scsi-hd' or
1114'scsi-cd' as appropriate to get a SCSI hard disk or CD-ROM as needed.
1115
1116``sga`` (removed in 8.0)
1117''''''''''''''''''''''''
1118
1119The ``sga`` device loaded an option ROM for x86 targets which enabled
1120SeaBIOS to send messages to the serial console. SeaBIOS 1.11.0 onwards
1121contains native support for this feature and thus use of the option
1122ROM approach was obsolete. The native SeaBIOS support can be activated
1123by using ``-machine graphics=off``.
1124
1125``pvrdma`` and the RDMA subsystem (removed in 9.1)
1126''''''''''''''''''''''''''''''''''''''''''''''''''
1127
1128The 'pvrdma' device and the whole RDMA subsystem have been removed.
1129
1130Related binaries
1131----------------
1132
1133``qemu-nbd --partition`` (removed in 5.0)
1134'''''''''''''''''''''''''''''''''''''''''
1135
1136The ``qemu-nbd --partition $digit`` code (also spelled ``-P``)
1137could only handle MBR partitions, and never correctly handled logical
1138partitions beyond partition 5.  Exporting a partition can still be
1139done by utilizing the ``--image-opts`` option with a raw blockdev
1140using the ``offset`` and ``size`` parameters layered on top of
1141any other existing blockdev. For example, if partition 1 is 100MiB
1142long starting at 1MiB, the old command::
1143
1144  qemu-nbd -t -P 1 -f qcow2 file.qcow2
1145
1146can be rewritten as::
1147
1148  qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.file.driver=file,file.file.filename=file.qcow2
1149
1150``qemu-img convert -n -o`` (removed in 5.1)
1151'''''''''''''''''''''''''''''''''''''''''''
1152
1153All options specified in ``-o`` are image creation options, so
1154they are now rejected when used with ``-n`` to skip image creation.
1155
1156
1157``qemu-img create -b bad file $size`` (removed in 5.1)
1158''''''''''''''''''''''''''''''''''''''''''''''''''''''
1159
1160When creating an image with a backing file that could not be opened,
1161``qemu-img create`` used to issue a warning about the failure but
1162proceed with the image creation if an explicit size was provided.
1163However, as the ``-u`` option exists for this purpose, it is safer to
1164enforce that any failure to open the backing image (including if the
1165backing file is missing or an incorrect format was specified) is an
1166error when ``-u`` is not used.
1167
1168``qemu-img amend`` to adjust backing file (removed in 6.1)
1169''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1170
1171The use of ``qemu-img amend`` to modify the name or format of a qcow2
1172backing image was never fully documented or tested, and interferes
1173with other amend operations that need access to the original backing
1174image (such as deciding whether a v3 zero cluster may be left
1175unallocated when converting to a v2 image).  Any changes to the
1176backing chain should be performed with ``qemu-img rebase -u`` either
1177before or after the remaining changes being performed by amend, as
1178appropriate.
1179
1180``qemu-img`` backing file without format (removed in 6.1)
1181'''''''''''''''''''''''''''''''''''''''''''''''''''''''''
1182
1183The use of ``qemu-img create``, ``qemu-img rebase``, or ``qemu-img
1184convert`` to create or modify an image that depends on a backing file
1185now requires that an explicit backing format be provided.  This is
1186for safety: if QEMU probes a different format than what you thought,
1187the data presented to the guest will be corrupt; similarly, presenting
1188a raw image to a guest allows a potential security exploit if a future
1189probe sees a non-raw image based on guest writes.
1190
1191To avoid creating unsafe backing chains, you must pass ``-o
1192backing_fmt=`` (or the shorthand ``-F`` during create) to specify the
1193intended backing format.  You may use ``qemu-img rebase -u`` to
1194retroactively add a backing format to an existing image.  However, be
1195aware that there are already potential security risks to blindly using
1196``qemu-img info`` to probe the format of an untrusted backing image,
1197when deciding what format to add into an existing image.
1198
1199Block devices
1200-------------
1201
1202VXHS backend (removed in 5.1)
1203'''''''''''''''''''''''''''''
1204
1205The VXHS code did not compile since v2.12.0. It was removed in 5.1.
1206
1207``sheepdog`` driver (removed in 6.0)
1208''''''''''''''''''''''''''''''''''''
1209
1210The corresponding upstream server project is no longer maintained.
1211Users are recommended to switch to an alternative distributed block
1212device driver such as RBD.
1213
1214Tools
1215-----
1216
1217virtiofsd (removed in 8.0)
1218''''''''''''''''''''''''''
1219
1220There is a newer Rust implementation of ``virtiofsd`` at
1221``https://gitlab.com/virtio-fs/virtiofsd``; this has been
1222stable for some time and is now widely used.
1223The command line and feature set is very close to the removed
1224C implementation.
1225
1226QEMU guest agent
1227----------------
1228
1229``--blacklist`` command line option (removed in 9.1)
1230''''''''''''''''''''''''''''''''''''''''''''''''''''
1231
1232``--blacklist`` has been replaced by ``--block-rpcs`` (which is a better
1233wording for what this option does). The short form ``-b`` still stays
1234the same and thus is the preferred way for scripts that should run with
1235both, older and future versions of QEMU.
1236
1237``blacklist`` config file option (removed in 9.1)
1238'''''''''''''''''''''''''''''''''''''''''''''''''
1239
1240The ``blacklist`` config file option has been renamed to ``block-rpcs``
1241(to be in sync with the renaming of the corresponding command line
1242option).
1243
1244.. _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
1245