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Diffstat (limited to 'docs/about/removed-features.rst')
| -rw-r--r-- | docs/about/removed-features.rst | 180 |
1 files changed, 151 insertions, 29 deletions
diff --git a/docs/about/removed-features.rst b/docs/about/removed-features.rst index fc7b28e..d7c2113 100644 --- a/docs/about/removed-features.rst +++ b/docs/about/removed-features.rst @@ -162,6 +162,12 @@ specified with ``-mem-path`` can actually provide the guest RAM configured with The ``name`` parameter of the ``-net`` option was a synonym for the ``id`` parameter, which should now be used instead. +RISC-V firmware not booted by default (removed in 5.1) +'''''''''''''''''''''''''''''''''''''''''''''''''''''' + +QEMU 5.1 changes the default behaviour from ``-bios none`` to ``-bios default`` +for the RISC-V ``virt`` machine and ``sifive_u`` machine. + ``-numa node,mem=...`` (removed in 5.1) ''''''''''''''''''''''''''''''''''''''' @@ -324,12 +330,6 @@ devices. Drives the board doesn't pick up can no longer be used with This option was undocumented and not used in the field. Use ``-device usb-ccid`` instead. -RISC-V firmware not booted by default (removed in 5.1) -'''''''''''''''''''''''''''''''''''''''''''''''''''''' - -QEMU 5.1 changes the default behaviour from ``-bios none`` to ``-bios default`` -for the RISC-V ``virt`` machine and ``sifive_u`` machine. - ``-no-quit`` (removed in 7.0) ''''''''''''''''''''''''''''' @@ -355,13 +355,13 @@ The ``-writeconfig`` option was not able to serialize the entire contents of the QEMU command line. It is thus considered a failed experiment and removed without a replacement. -``loaded`` property of ``secret`` and ``secret_keyring`` objects (removed in 7.1) -''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' +``loaded`` property of secret and TLS credential objects (removed in 9.2) +''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' The ``loaded=on`` option in the command line or QMP ``object-add`` either had no effect (if ``loaded`` was the last option) or caused options to be effectively ignored as if they were not given. The property is therefore -useless and should simply be removed. +useless and has been removed. ``opened`` property of ``rng-*`` objects (removed in 7.1) ''''''''''''''''''''''''''''''''''''''''''''''''''''''''' @@ -403,13 +403,13 @@ Sound card devices should be created using ``-device`` or ``-audio``. The exception is ``pcspk`` which can be activated using ``-machine pcspk-audiodev=<name>``. -``-watchdog`` (since 7.2) -''''''''''''''''''''''''' +``-watchdog`` (removed in 7.2) +'''''''''''''''''''''''''''''' Use ``-device`` instead. -Hexadecimal sizes with scaling multipliers (since 8.0) -'''''''''''''''''''''''''''''''''''''''''''''''''''''' +Hexadecimal sizes with scaling multipliers (removed in 8.0) +''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' Input parameters that take a size value should only use a size suffix (such as 'k' or 'M') when the base is written in decimal, and not when @@ -510,13 +510,56 @@ than zero. Removed along with the ``compression`` migration capability. -``-device virtio-blk,scsi=on|off`` (since 9.1) -'''''''''''''''''''''''''''''''''''''''''''''' +``-device virtio-blk,scsi=on|off`` (removed in 9.1) +''''''''''''''''''''''''''''''''''''''''''''''''''' The virtio-blk SCSI passthrough feature is a legacy VIRTIO feature. VIRTIO 1.0 and later do not support it because the virtio-scsi device was introduced for full SCSI support. Use virtio-scsi instead when SCSI passthrough is required. +``-fsdev proxy`` and ``-virtfs proxy`` (removed in 9.2) +''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +The 9p ``proxy`` filesystem backend driver was originally developed to +enhance security by dispatching low level filesystem operations from 9p +server (QEMU process) over to a separate process (the virtfs-proxy-helper +binary). However the proxy backend was much slower than the local backend, +didn't see any development in years, and showed to be less secure, +especially due to the fact that its helper daemon must be run as root. + +Use ``local``, possibly mapping permissions et al by using its 'mapped' +security model option, or switch to ``virtiofs``. The virtiofs daemon +``virtiofsd`` uses vhost to eliminate the high latency costs of the 9p +``proxy`` backend. + +``-portrait`` and ``-rotate`` (removed in 9.2) +'''''''''''''''''''''''''''''''''''''''''''''' + +The ``-portrait`` and ``-rotate`` options were documented as only +working with the PXA LCD device, and all the machine types using +that display device were removed in 9.2, so these options also +have been dropped. + +These options were intended to simulate a mobile device being +rotated by the user, and had three effects: + +* the display output was rotated by 90, 180 or 270 degrees +* the mouse/trackpad input was rotated the opposite way +* the machine model would signal to the guest about its + orientation + +Of these three things, the input-rotation was coded without being +restricted to boards which supported the full set of device-rotation +handling, so in theory the options were usable on other machine models +to produce an odd effect (rotating input but not display output). But +this was never intended or documented behaviour, so we have dropped +the options along with the machine models they were intended for. + +``-runas`` (removed in 10.0) +'''''''''''''''''''''''''''' + +Use ``-run-with user=..`` instead. + User-mode emulator command line arguments ----------------------------------------- @@ -679,6 +722,15 @@ Use ``multifd-channels`` instead. Use ``multifd-compression`` instead. +Incorrectly typed ``device_add`` arguments (since 9.2) +'''''''''''''''''''''''''''''''''''''''''''''''''''''' + +Due to shortcomings in the internal implementation of ``device_add``, +QEMU used to incorrectly accept certain invalid arguments. Any object +or list arguments were silently ignored. Other argument types were not +checked, but an implicit conversion happened, so that e.g. string +values could be assigned to integer device properties or vice versa. + QEMU Machine Protocol (QMP) events ---------------------------------- @@ -815,6 +867,15 @@ QEMU. Since all recent x86 hardware from the past >10 years is capable of the 64-bit x86 extensions, a corresponding 64-bit OS should be used instead. +32-bit hosts for 64-bit guests (removed in 10.0) +'''''''''''''''''''''''''''''''''''''''''''''''' + +In general, 32-bit hosts cannot support the memory space or atomicity +requirements of 64-bit guests. Prior to 10.0, QEMU attempted to +work around the atomicity issues in system mode by running all vCPUs +in a single thread context; in user mode atomicity was simply broken. +From 10.0, QEMU has disabled configuration of 64-bit guests on 32-bit hosts. + Guest Emulator ISAs ------------------- @@ -889,6 +950,21 @@ Nios II CPU (removed in 9.1) QEMU Nios II architecture was orphan; Intel has EOL'ed the Nios II processor IP (see `Intel discontinuance notification`_). +CRIS CPU architecture (removed in 9.2) +'''''''''''''''''''''''''''''''''''''' + +The CRIS architecture was pulled from Linux in 4.17 and the compiler +was no longer packaged in any distro making it harder to run the +``check-tcg`` tests. + +RISC-V 'any' CPU type ``-cpu any`` (removed in 9.2) +''''''''''''''''''''''''''''''''''''''''''''''''''' + +The 'any' CPU type was introduced back in 2018 and was around since the +initial RISC-V QEMU port. Its usage was always been unclear: users don't know +what to expect from a CPU called 'any', and in fact the CPU does not do anything +special that isn't already done by the default CPUs rv32/rv64. + System accelerators ------------------- @@ -899,21 +975,28 @@ Userspace local APIC with KVM (x86, removed in 8.0) a local APIC. The ``split`` setting is supported, as is using ``-M kernel-irqchip=off`` when the CPU does not have a local APIC. -HAXM (``-accel hax``) (removed in 8.2) -'''''''''''''''''''''''''''''''''''''' - -The HAXM project has been retired (see https://github.com/intel/haxm#status). -Use "whpx" (on Windows) or "hvf" (on macOS) instead. - MIPS "Trap-and-Emulate" KVM support (removed in 8.0) '''''''''''''''''''''''''''''''''''''''''''''''''''' The MIPS "Trap-and-Emulate" KVM host and guest support was removed from Linux in 2021, and is not supported anymore by QEMU either. +HAXM (``-accel hax``) (removed in 8.2) +'''''''''''''''''''''''''''''''''''''' + +The HAXM project has been retired (see https://github.com/intel/haxm#status). +Use "whpx" (on Windows) or "hvf" (on macOS) instead. + System emulator machines ------------------------ +Versioned machine types (aarch64, arm, i386, m68k, ppc64, s390x, x86_64) +'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +In accordance with our versioned machine type deprecation policy, all machine +types with version |VER_MACHINE_DELETION_VERSION|, or older, have been +removed. + ``s390-virtio`` (removed in 2.6) '''''''''''''''''''''''''''''''' @@ -948,12 +1031,6 @@ mips ``fulong2e`` machine alias (removed in 6.0) This machine has been renamed ``fuloong2e``. -``pc-0.10`` up to ``pc-i440fx-2.3`` (removed in 4.0 up to 9.0) -'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' - -These machine types were very old and likely could not be used for live -migration from old QEMU versions anymore. Use a newer machine type instead. - Raspberry Pi ``raspi2`` and ``raspi3`` machines (removed in 6.2) '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' @@ -978,6 +1055,51 @@ Nios II ``10m50-ghrd`` and ``nios2-generic-nommu`` machines (removed in 9.1) The Nios II architecture was orphan. +``shix`` (removed in 9.2) +''''''''''''''''''''''''' + +The machine was unmaintained. + +Arm machines ``akita``, ``borzoi``, ``cheetah``, ``connex``, ``mainstone``, ``n800``, ``n810``, ``spitz``, ``terrier``, ``tosa``, ``verdex``, ``z2`` (removed in 9.2) +''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +QEMU included models of some machine types where the QEMU code that +emulates their SoCs was very old and unmaintained. This code was +blocking our ability to move forward with various changes across +the codebase, and over many years nobody has been interested in +trying to modernise it. We don't expect any of these machines to have +a large number of users, because they're all modelling hardware that +has now passed away into history. We are therefore dropping support +for all machine types using the PXA2xx and OMAP2 SoCs. We are also +dropping the ``cheetah`` OMAP1 board, because we don't have any +test images for it and don't know of anybody who does. + +Aspeed ``tacoma-bmc`` machine (removed in 10.0) +''''''''''''''''''''''''''''''''''''''''''''''' + +The ``tacoma-bmc`` machine was removed because it didn't bring much +compared to the ``rainier-bmc`` machine. Also, the ``tacoma-bmc`` was +a board used for bring up of the AST2600 SoC that never left the +labs. It can be easily replaced by the ``rainier-bmc`` machine, which +was the actual final product, or by the ``ast2600-evb`` with some +tweaks. + +ppc ``ref405ep`` machine (removed in 10.0) +'''''''''''''''''''''''''''''''''''''''''' + +This machine was removed because PPC 405 CPU have no known users, +firmware images are not available, OpenWRT dropped support in 2019, +U-Boot in 2017, and Linux in 2024. + +Big-Endian variants of ``petalogix-ml605`` and ``xlnx-zynqmp-pmu`` machines (removed in 10.1) +''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +Both the MicroBlaze ``petalogix-ml605`` and ``xlnx-zynqmp-pmu`` machines +were added for little endian CPUs. Big endian support was never tested +and likely never worked. Starting with QEMU v10.1, the machines are now +only available as little-endian machines. + + linux-user mode CPUs -------------------- @@ -1006,8 +1128,8 @@ processor IP (see `Intel discontinuance notification`_). TCG introspection features -------------------------- -TCG trace-events (since 6.2) -'''''''''''''''''''''''''''' +TCG trace-events (removed in 7.0) +''''''''''''''''''''''''''''''''' The ability to add new TCG trace points had bit rotted and as the feature can be replicated with TCG plugins it was removed. If |