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if=none,id=dr,...``). 18 19``-net channel`` (removed in 2.12) 20'''''''''''''''''''''''''''''''''' 21 22This option has been replaced by ``-net user,guestfwd=...``. 23 24``-net dump`` (removed in 2.12) 25''''''''''''''''''''''''''''''' 26 27``-net dump[,vlan=n][,file=filename][,len=maxlen]`` has been replaced by 28``-object filter-dump,id=id,netdev=dev[,file=filename][,maxlen=maxlen]``. 29Note that the new syntax works with netdev IDs instead of the old "vlan" hubs.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