qemu-deprecated.texi

   1 @node Deprecated features
   2 @appendix Deprecated features
   3
   4 In general features are intended to be supported indefinitely once
   5 introduced into QEMU. In the event that a feature needs to be removed,
   6 it will be listed in this appendix. The feature will remain functional
   7 for 2 releases prior to actual removal. Deprecated features may also
   8 generate warnings on the console when QEMU starts up, or if activated
   9 via a monitor command, however, this is not a mandatory requirement.
  10
  11 Prior to the 2.10.0 release there was no official policy on how
  12 long features would be deprecated prior to their removal, nor
  13 any documented list of which features were deprecated. Thus
  14 any features deprecated prior to 2.10.0 will be treated as if
  15 they were first deprecated in the 2.10.0 release.
  16
  17 What follows is a list of all features currently marked as
  18 deprecated.
  19
  20 @section Build options
  21
  22 @subsection SDL 1.2
  23
  24 Previously QEMU has supported building against both SDL 1.2
  25 and 2.0 series APIs. Support for the SDL 1.2 builds will be
  26 discontinued, so maintainers should switch to using SDL 2.0,
  27 which is the default.
  28
  29 @section System emulator command line arguments
  30
  31 @subsection -machine enforce-config-section=on|off (since 3.1)
  32
  33 The @option{enforce-config-section} parameter is replaced by the
  34 @option{-global migration.send-configuration=@var{on|off}} option.
  35
  36 @subsection -no-kvm (since 1.3.0)
  37
  38 The ``-no-kvm'' argument is now a synonym for setting
  39 ``-machine accel=tcg''.
  40
  41 @subsection -usbdevice (since 2.10.0)
  42
  43 The ``-usbdevice DEV'' argument is now a synonym for setting
  44 the ``-device usb-DEV'' argument instead. The deprecated syntax
  45 would automatically enable USB support on the machine type.
  46 If using the new syntax, USB support must be explicitly
  47 enabled via the ``-machine usb=on'' argument.
  48
  49 @subsection -no-frame (since 2.12.0)
  50
  51 The @code{--no-frame} argument works with SDL 1.2 only. The other user
  52 interfaces never implemented this in the first place. So this will be
  53 removed together with SDL 1.2 support.
  54
  55 @subsection -virtioconsole (since 3.0.0)
  56
  57 Option @option{-virtioconsole} has been replaced by
  58 @option{-device virtconsole}.
  59
  60 @subsection -clock (since 3.0.0)
  61
  62 The @code{-clock} option is ignored since QEMU version 1.7.0. There is no
  63 replacement since it is not needed anymore.
  64
  65 @subsection -enable-hax (since 3.0.0)
  66
  67 The @option{-enable-hax} option has been replaced by @option{-accel hax}.
  68 Both options have been introduced in QEMU version 2.9.0.
  69
  70 @subsection -drive file=json:@{...@{'driver':'file'@}@} (since 3.0)
  71
  72 The 'file' driver for drives is no longer appropriate for character or host
  73 devices and will only accept regular files (S_IFREG). The correct driver
  74 for these file types is 'host_cdrom' or 'host_device' as appropriate.
  75
  76 @subsection -net ...,name=@var{name} (since 3.1)
  77
  78 The @option{name} parameter of the @option{-net} option is a synonym
  79 for the @option{id} parameter, which should now be used instead.
  80
  81 @subsection -smp (invalid topologies) (since 3.1)
  82
  83 CPU topology properties should describe whole machine topology including
  84 possible CPUs.
  85
  86 However, historically it was possible to start QEMU with an incorrect topology
  87 where @math{@var{n} <= @var{sockets} * @var{cores} * @var{threads} < @var{maxcpus}},
  88 which could lead to an incorrect topology enumeration by the guest.
  89 Support for invalid topologies will be removed, the user must ensure
  90 topologies described with -smp include all possible cpus, i.e.
  91   @math{@var{sockets} * @var{cores} * @var{threads} = @var{maxcpus}}.
  92
  93 @section QEMU Machine Protocol (QMP) commands
  94
  95 @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)
  96
  97 "autoload" parameter is now ignored. All bitmaps are automatically loaded
  98 from qcow2 images.
  99
 100 @subsection query-cpus (since 2.12.0)
 101
 102 The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.
 103
 104 @subsection query-cpus-fast "arch" output member (since 3.0.0)
 105
 106 The ``arch'' output member of the ``query-cpus-fast'' command is
 107 replaced by the ``target'' output member.
 108
 109 @section System emulator human monitor commands
 110
 111 @subsection The hub_id parameter of 'hostfwd_add' / 'hostfwd_remove' (since 3.1)
 112
 113 The @option{[hub_id name]} parameter tuple of the 'hostfwd_add' and
 114 'hostfwd_remove' HMP commands has been replaced by @option{netdev_id}.
 115
 116 @subsection cpu-add (since 3.1)
 117
 118 Use ``device_add'' for hotplugging vCPUs instead of ``cpu-add''.  See
 119 documentation of ``query-hotpluggable-cpus'' for additional details.
 120
 121 @section System emulator devices
 122
 123 @subsection ivshmem (since 2.6.0)
 124
 125 The ``ivshmem'' device type is replaced by either the ``ivshmem-plain''
 126 or ``ivshmem-doorbell`` device types.
 127
 128 @subsection bluetooth (since 3.1)
 129
 130 The bluetooth subsystem is unmaintained since many years and likely bitrotten
 131 quite a bit. It will be removed without replacement unless some users speaks
 132 up at the @email{qemu-devel@@nongnu.org} mailing list with information about
 133 their usecases.
 134
 135 @section System emulator machines
 136
 137 @subsection pc-0.10 and pc-0.11 (since 3.0)
 138
 139 These machine types are very old and likely can not be used for live migration
 140 from old QEMU versions anymore. A newer machine type should be used instead.
 141
 142 @subsection prep (PowerPC) (since 3.1)
 143
 144 This machine type uses an unmaintained firmware, broken in lots of ways,
 145 and unable to start post-2004 operating systems. 40p machine type should be
 146 used instead.
 147
 148 @section Device options
 149
 150 @subsection Block device options
 151
 152 @subsubsection "backing": "" (since 2.12.0)
 153
 154 In order to prevent QEMU from automatically opening an image's backing
 155 chain, use ``"backing": null'' instead.
 156
 157 @subsubsection rbd keyvalue pair encoded filenames: "" (since 3.1.0)
 158
 159 Options for ``rbd'' should be specified according to its runtime options,
 160 like other block drivers.  Legacy parsing of keyvalue pair encoded
 161 filenames is useful to open images with the old format for backing files;
 162 These image files should be updated to use the current format.
 163
 164 Example of legacy encoding:
 165
 166 @code{json:@{"file.driver":"rbd", "file.filename":"rbd:rbd/name"@}}
 167
 168 The above, converted to the current supported format:
 169
 170 @code{json:@{"file.driver":"rbd", "file.pool":"rbd", "file.image":"name"@}}
 171
 172 @subsection vio-spapr-device device options
 173
 174 @subsubsection "irq": "" (since 3.0.0)
 175
 176 The ``irq'' property is obsoleted.