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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/system/deprecated.rst | 232 | ||||
| -rw-r--r-- | docs/system/index.rst | 1 | ||||
| -rw-r--r-- | docs/system/removed-features.rst | 231 |
3 files changed, 232 insertions, 232 deletions
diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst index 0b22812..b0d44a0 100644 --- a/docs/system/deprecated.rst +++ b/docs/system/deprecated.rst @@ -486,235 +486,3 @@ nanoMIPS ISA The ``nanoMIPS`` ISA has never been upstreamed to any compiler toolchain. As it is hard to generate binaries for it, declare it deprecated. - - -Recently removed features -========================= - -What follows is a record of recently removed, formerly deprecated -features that serves as a record for users who have encountered -trouble after a recent upgrade. - -System emulator command line arguments --------------------------------------- - -``-net ...,name=``\ *name* (removed in 5.1) -''''''''''''''''''''''''''''''''''''''''''' - -The ``name`` parameter of the ``-net`` option was a synonym -for the ``id`` parameter, which should now be used instead. - -``-no-kvm`` (removed in 5.2) -'''''''''''''''''''''''''''' - -The ``-no-kvm`` argument was a synonym for setting ``-machine accel=tcg``. - -``-tb-size`` option (removed in 6.0) -'''''''''''''''''''''''''''''''''''' - -QEMU 5.0 introduced an alternative syntax to specify the size of the translation -block cache, ``-accel tcg,tb-size=``. - -QEMU Machine Protocol (QMP) commands ------------------------------------- - -``block-dirty-bitmap-add`` "autoload" parameter (since 4.2.0) -''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' - -The "autoload" parameter has been ignored since 2.12.0. All bitmaps -are automatically loaded from qcow2 images. - -``cpu-add`` (removed in 5.2) -'''''''''''''''''''''''''''' - -Use ``device_add`` for hotplugging vCPUs instead of ``cpu-add``. See -documentation of ``query-hotpluggable-cpus`` for additional details. - -Human Monitor Protocol (HMP) commands -------------------------------------- - -The ``hub_id`` parameter of ``hostfwd_add`` / ``hostfwd_remove`` (removed in 5.0) -''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' - -The ``[hub_id name]`` parameter tuple of the 'hostfwd_add' and -'hostfwd_remove' HMP commands has been replaced by ``netdev_id``. - -``cpu-add`` (removed in 5.2) -'''''''''''''''''''''''''''' - -Use ``device_add`` for hotplugging vCPUs instead of ``cpu-add``. See -documentation of ``query-hotpluggable-cpus`` for additional details. - -Guest Emulator ISAs -------------------- - -RISC-V ISA privilege specification version 1.09.1 (removed in 5.1) -'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' - -The RISC-V ISA privilege specification version 1.09.1 has been removed. -QEMU supports both the newer version 1.10.0 and the ratified version 1.11.0, these -should be used instead of the 1.09.1 version. - -System emulator CPUS --------------------- - -KVM guest support on 32-bit Arm hosts (removed in 5.2) -'''''''''''''''''''''''''''''''''''''''''''''''''''''' - -The Linux kernel has dropped support for allowing 32-bit Arm systems -to host KVM guests as of the 5.7 kernel. Accordingly, QEMU is deprecating -its support for this configuration and will remove it in a future version. -Running 32-bit guests on a 64-bit Arm host remains supported. - -RISC-V ISA Specific CPUs (removed in 5.1) -''''''''''''''''''''''''''''''''''''''''' - -The RISC-V cpus with the ISA version in the CPU name have been removed. The -four CPUs are: ``rv32gcsu-v1.9.1``, ``rv32gcsu-v1.10.0``, ``rv64gcsu-v1.9.1`` and -``rv64gcsu-v1.10.0``. Instead the version can be specified via the CPU ``priv_spec`` -option when using the ``rv32`` or ``rv64`` CPUs. - -RISC-V no MMU CPUs (removed in 5.1) -''''''''''''''''''''''''''''''''''' - -The RISC-V no MMU cpus have been removed. The two CPUs: ``rv32imacu-nommu`` and -``rv64imacu-nommu`` can no longer be used. Instead the MMU status can be specified -via the CPU ``mmu`` option when using the ``rv32`` or ``rv64`` CPUs. - -System emulator machines ------------------------- - -``spike_v1.9.1`` and ``spike_v1.10`` (removed in 5.1) -''''''''''''''''''''''''''''''''''''''''''''''''''''' - -The version specific Spike machines have been removed in favour of the -generic ``spike`` machine. If you need to specify an older version of the RISC-V -spec you can use the ``-cpu rv64gcsu,priv_spec=v1.10.0`` command line argument. - -mips ``r4k`` platform (removed in 5.2) -'''''''''''''''''''''''''''''''''''''' - -This machine type was very old and unmaintained. Users should use the ``malta`` -machine type instead. - -Related binaries ----------------- - -``qemu-nbd --partition`` (removed in 5.0) -''''''''''''''''''''''''''''''''''''''''' - -The ``qemu-nbd --partition $digit`` code (also spelled ``-P``) -could only handle MBR partitions, and never correctly handled logical -partitions beyond partition 5. Exporting a partition can still be -done by utilizing the ``--image-opts`` option with a raw blockdev -using the ``offset`` and ``size`` parameters layered on top of -any other existing blockdev. For example, if partition 1 is 100MiB -long starting at 1MiB, the old command:: - - qemu-nbd -t -P 1 -f qcow2 file.qcow2 - -can be rewritten as:: - - qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.file.driver=file,file.file.filename=file.qcow2 - -``qemu-img convert -n -o`` (removed in 5.1) -''''''''''''''''''''''''''''''''''''''''''' - -All options specified in ``-o`` are image creation options, so -they are now rejected when used with ``-n`` to skip image creation. - - -``qemu-img create -b bad file $size`` (removed in 5.1) -'''''''''''''''''''''''''''''''''''''''''''''''''''''' - -When creating an image with a backing file that could not be opened, -``qemu-img create`` used to issue a warning about the failure but -proceed with the image creation if an explicit size was provided. -However, as the ``-u`` option exists for this purpose, it is safer to -enforce that any failure to open the backing image (including if the -backing file is missing or an incorrect format was specified) is an -error when ``-u`` is not used. - -Command line options --------------------- - -``-smp`` (invalid topologies) (removed 5.2) -''''''''''''''''''''''''''''''''''''''''''' - -CPU topology properties should describe whole machine topology including -possible CPUs. - -However, historically it was possible to start QEMU with an incorrect topology -where *n* <= *sockets* * *cores* * *threads* < *maxcpus*, -which could lead to an incorrect topology enumeration by the guest. -Support for invalid topologies is removed, the user must ensure -topologies described with -smp include all possible cpus, i.e. -*sockets* * *cores* * *threads* = *maxcpus*. - -``-numa`` node (without memory specified) (removed 5.2) -''''''''''''''''''''''''''''''''''''''''''''''''''''''' - -Splitting RAM by default between NUMA nodes had the same issues as ``mem`` -parameter with the difference that the role of the user plays QEMU using -implicit generic or board specific splitting rule. -Use ``memdev`` with *memory-backend-ram* backend or ``mem`` (if -it's supported by used machine type) to define mapping explicitly instead. -Users of existing VMs, wishing to preserve the same RAM distribution, should -configure it explicitly using ``-numa node,memdev`` options. Current RAM -distribution can be retrieved using HMP command ``info numa`` and if separate -memory devices (pc|nv-dimm) are present use ``info memory-device`` and subtract -device memory from output of ``info numa``. - -``-numa node,mem=``\ *size* (removed in 5.1) -'''''''''''''''''''''''''''''''''''''''''''' - -The parameter ``mem`` of ``-numa node`` was used to assign a part of -guest RAM to a NUMA node. But when using it, it's impossible to manage a specified -RAM chunk on the host side (like bind it to a host node, setting bind policy, ...), -so the guest ends up with the fake NUMA configuration with suboptiomal performance. -However since 2014 there is an alternative way to assign RAM to a NUMA node -using parameter ``memdev``, which does the same as ``mem`` and adds -means to actually manage node RAM on the host side. Use parameter ``memdev`` -with *memory-backend-ram* backend as replacement for parameter ``mem`` -to achieve the same fake NUMA effect or a properly configured -*memory-backend-file* backend to actually benefit from NUMA configuration. -New machine versions (since 5.1) will not accept the option but it will still -work with old machine types. User can check the QAPI schema to see if the legacy -option is supported by looking at MachineInfo::numa-mem-supported property. - -``-mem-path`` fallback to RAM (removed in 5.0) -'''''''''''''''''''''''''''''''''''''''''''''' - -If guest RAM allocation from file pointed by ``mem-path`` failed, -QEMU was falling back to allocating from RAM, which might have resulted -in unpredictable behavior since the backing file specified by the user -as ignored. Currently, users are responsible for making sure the backing storage -specified with ``-mem-path`` can actually provide the guest RAM configured with -``-m`` and QEMU fails to start up if RAM allocation is unsuccessful. - -``-smp`` (invalid topologies) (removed 5.2) -''''''''''''''''''''''''''''''''''''''''''' - -CPU topology properties should describe whole machine topology including -possible CPUs. - -However, historically it was possible to start QEMU with an incorrect topology -where *n* <= *sockets* * *cores* * *threads* < *maxcpus*, -which could lead to an incorrect topology enumeration by the guest. -Support for invalid topologies is removed, the user must ensure -topologies described with -smp include all possible cpus, i.e. -*sockets* * *cores* * *threads* = *maxcpus*. - -``-machine enforce-config-section=on|off`` (removed 5.2) -'''''''''''''''''''''''''''''''''''''''''''''''''''''''' - -The ``enforce-config-section`` property was replaced by the -``-global migration.send-configuration={on|off}`` option. - -Block devices -------------- - -VXHS backend (removed in 5.1) -''''''''''''''''''''''''''''' - -The VXHS code does not compile since v2.12.0. It was removed in 5.1. diff --git a/docs/system/index.rst b/docs/system/index.rst index e5a3581..d40f72c 100644 --- a/docs/system/index.rst +++ b/docs/system/index.rst @@ -35,5 +35,6 @@ Contents: targets security deprecated + removed-features build-platforms license diff --git a/docs/system/removed-features.rst b/docs/system/removed-features.rst new file mode 100644 index 0000000..8a974f7 --- /dev/null +++ b/docs/system/removed-features.rst @@ -0,0 +1,231 @@ + +Removed features +================ + +What follows is a record of recently removed, formerly deprecated +features that serves as a record for users who have encountered +trouble after a recent upgrade. + +System emulator command line arguments +-------------------------------------- + +``-net ...,name=``\ *name* (removed in 5.1) +''''''''''''''''''''''''''''''''''''''''''' + +The ``name`` parameter of the ``-net`` option was a synonym +for the ``id`` parameter, which should now be used instead. + +``-no-kvm`` (removed in 5.2) +'''''''''''''''''''''''''''' + +The ``-no-kvm`` argument was a synonym for setting ``-machine accel=tcg``. + +``-tb-size`` option (removed in 6.0) +'''''''''''''''''''''''''''''''''''' + +QEMU 5.0 introduced an alternative syntax to specify the size of the translation +block cache, ``-accel tcg,tb-size=``. + +QEMU Machine Protocol (QMP) commands +------------------------------------ + +``block-dirty-bitmap-add`` "autoload" parameter (removed in 4.2.0) +'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +The "autoload" parameter has been ignored since 2.12.0. All bitmaps +are automatically loaded from qcow2 images. + +``cpu-add`` (removed in 5.2) +'''''''''''''''''''''''''''' + +Use ``device_add`` for hotplugging vCPUs instead of ``cpu-add``. See +documentation of ``query-hotpluggable-cpus`` for additional details. + +Human Monitor Protocol (HMP) commands +------------------------------------- + +The ``hub_id`` parameter of ``hostfwd_add`` / ``hostfwd_remove`` (removed in 5.0) +''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +The ``[hub_id name]`` parameter tuple of the 'hostfwd_add' and +'hostfwd_remove' HMP commands has been replaced by ``netdev_id``. + +``cpu-add`` (removed in 5.2) +'''''''''''''''''''''''''''' + +Use ``device_add`` for hotplugging vCPUs instead of ``cpu-add``. See +documentation of ``query-hotpluggable-cpus`` for additional details. + +Guest Emulator ISAs +------------------- + +RISC-V ISA privilege specification version 1.09.1 (removed in 5.1) +'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +The RISC-V ISA privilege specification version 1.09.1 has been removed. +QEMU supports both the newer version 1.10.0 and the ratified version 1.11.0, these +should be used instead of the 1.09.1 version. + +System emulator CPUS +-------------------- + +KVM guest support on 32-bit Arm hosts (removed in 5.2) +'''''''''''''''''''''''''''''''''''''''''''''''''''''' + +The Linux kernel has dropped support for allowing 32-bit Arm systems +to host KVM guests as of the 5.7 kernel. Accordingly, QEMU is deprecating +its support for this configuration and will remove it in a future version. +Running 32-bit guests on a 64-bit Arm host remains supported. + +RISC-V ISA Specific CPUs (removed in 5.1) +''''''''''''''''''''''''''''''''''''''''' + +The RISC-V cpus with the ISA version in the CPU name have been removed. The +four CPUs are: ``rv32gcsu-v1.9.1``, ``rv32gcsu-v1.10.0``, ``rv64gcsu-v1.9.1`` and +``rv64gcsu-v1.10.0``. Instead the version can be specified via the CPU ``priv_spec`` +option when using the ``rv32`` or ``rv64`` CPUs. + +RISC-V no MMU CPUs (removed in 5.1) +''''''''''''''''''''''''''''''''''' + +The RISC-V no MMU cpus have been removed. The two CPUs: ``rv32imacu-nommu`` and +``rv64imacu-nommu`` can no longer be used. Instead the MMU status can be specified +via the CPU ``mmu`` option when using the ``rv32`` or ``rv64`` CPUs. + +System emulator machines +------------------------ + +``spike_v1.9.1`` and ``spike_v1.10`` (removed in 5.1) +''''''''''''''''''''''''''''''''''''''''''''''''''''' + +The version specific Spike machines have been removed in favour of the +generic ``spike`` machine. If you need to specify an older version of the RISC-V +spec you can use the ``-cpu rv64gcsu,priv_spec=v1.10.0`` command line argument. + +mips ``r4k`` platform (removed in 5.2) +'''''''''''''''''''''''''''''''''''''' + +This machine type was very old and unmaintained. Users should use the ``malta`` +machine type instead. + +Related binaries +---------------- + +``qemu-nbd --partition`` (removed in 5.0) +''''''''''''''''''''''''''''''''''''''''' + +The ``qemu-nbd --partition $digit`` code (also spelled ``-P``) +could only handle MBR partitions, and never correctly handled logical +partitions beyond partition 5. Exporting a partition can still be +done by utilizing the ``--image-opts`` option with a raw blockdev +using the ``offset`` and ``size`` parameters layered on top of +any other existing blockdev. For example, if partition 1 is 100MiB +long starting at 1MiB, the old command:: + + qemu-nbd -t -P 1 -f qcow2 file.qcow2 + +can be rewritten as:: + + qemu-nbd -t --image-opts driver=raw,offset=1M,size=100M,file.driver=qcow2,file.file.driver=file,file.file.filename=file.qcow2 + +``qemu-img convert -n -o`` (removed in 5.1) +''''''''''''''''''''''''''''''''''''''''''' + +All options specified in ``-o`` are image creation options, so +they are now rejected when used with ``-n`` to skip image creation. + + +``qemu-img create -b bad file $size`` (removed in 5.1) +'''''''''''''''''''''''''''''''''''''''''''''''''''''' + +When creating an image with a backing file that could not be opened, +``qemu-img create`` used to issue a warning about the failure but +proceed with the image creation if an explicit size was provided. +However, as the ``-u`` option exists for this purpose, it is safer to +enforce that any failure to open the backing image (including if the +backing file is missing or an incorrect format was specified) is an +error when ``-u`` is not used. + +Command line options +-------------------- + +``-smp`` (invalid topologies) (removed 5.2) +''''''''''''''''''''''''''''''''''''''''''' + +CPU topology properties should describe whole machine topology including +possible CPUs. + +However, historically it was possible to start QEMU with an incorrect topology +where *n* <= *sockets* * *cores* * *threads* < *maxcpus*, +which could lead to an incorrect topology enumeration by the guest. +Support for invalid topologies is removed, the user must ensure +topologies described with -smp include all possible cpus, i.e. +*sockets* * *cores* * *threads* = *maxcpus*. + +``-numa`` node (without memory specified) (removed 5.2) +''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +Splitting RAM by default between NUMA nodes had the same issues as ``mem`` +parameter with the difference that the role of the user plays QEMU using +implicit generic or board specific splitting rule. +Use ``memdev`` with *memory-backend-ram* backend or ``mem`` (if +it's supported by used machine type) to define mapping explicitly instead. +Users of existing VMs, wishing to preserve the same RAM distribution, should +configure it explicitly using ``-numa node,memdev`` options. Current RAM +distribution can be retrieved using HMP command ``info numa`` and if separate +memory devices (pc|nv-dimm) are present use ``info memory-device`` and subtract +device memory from output of ``info numa``. + +``-numa node,mem=``\ *size* (removed in 5.1) +'''''''''''''''''''''''''''''''''''''''''''' + +The parameter ``mem`` of ``-numa node`` was used to assign a part of +guest RAM to a NUMA node. But when using it, it's impossible to manage a specified +RAM chunk on the host side (like bind it to a host node, setting bind policy, ...), +so the guest ends up with the fake NUMA configuration with suboptiomal performance. +However since 2014 there is an alternative way to assign RAM to a NUMA node +using parameter ``memdev``, which does the same as ``mem`` and adds +means to actually manage node RAM on the host side. Use parameter ``memdev`` +with *memory-backend-ram* backend as replacement for parameter ``mem`` +to achieve the same fake NUMA effect or a properly configured +*memory-backend-file* backend to actually benefit from NUMA configuration. +New machine versions (since 5.1) will not accept the option but it will still +work with old machine types. User can check the QAPI schema to see if the legacy +option is supported by looking at MachineInfo::numa-mem-supported property. + +``-mem-path`` fallback to RAM (removed in 5.0) +'''''''''''''''''''''''''''''''''''''''''''''' + +If guest RAM allocation from file pointed by ``mem-path`` failed, +QEMU was falling back to allocating from RAM, which might have resulted +in unpredictable behavior since the backing file specified by the user +as ignored. Currently, users are responsible for making sure the backing storage +specified with ``-mem-path`` can actually provide the guest RAM configured with +``-m`` and QEMU fails to start up if RAM allocation is unsuccessful. + +``-smp`` (invalid topologies) (removed 5.2) +''''''''''''''''''''''''''''''''''''''''''' + +CPU topology properties should describe whole machine topology including +possible CPUs. + +However, historically it was possible to start QEMU with an incorrect topology +where *n* <= *sockets* * *cores* * *threads* < *maxcpus*, +which could lead to an incorrect topology enumeration by the guest. +Support for invalid topologies is removed, the user must ensure +topologies described with -smp include all possible cpus, i.e. +*sockets* * *cores* * *threads* = *maxcpus*. + +``-machine enforce-config-section=on|off`` (removed 5.2) +'''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +The ``enforce-config-section`` property was replaced by the +``-global migration.send-configuration={on|off}`` option. + +Block devices +------------- + +VXHS backend (removed in 5.1) +''''''''''''''''''''''''''''' + +The VXHS code did not compile since v2.12.0. It was removed in 5.1. |