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 -fsdev handle (since 2.12.0)
  50
  51 The ``handle'' fsdev backend does not support symlinks and causes the 9p
  52 filesystem in the guest to fail a fair amount of tests from the PJD POSIX
  53 filesystem test suite. Also it requires the CAP_DAC_READ_SEARCH capability,
  54 which is not the recommended way to run QEMU. This backend should not be
  55 used and it will be removed with no replacement.
  56
  57 @subsection -no-frame (since 2.12.0)
  58
  59 The @code{--no-frame} argument works with SDL 1.2 only. The other user
  60 interfaces never implemented this in the first place. So this will be
  61 removed together with SDL 1.2 support.
  62
  63 @subsection -virtioconsole (since 3.0.0)
  64
  65 Option @option{-virtioconsole} has been replaced by
  66 @option{-device virtconsole}.
  67
  68 @subsection -clock (since 3.0.0)
  69
  70 The @code{-clock} option is ignored since QEMU version 1.7.0. There is no
  71 replacement since it is not needed anymore.
  72
  73 @subsection -enable-hax (since 3.0.0)
  74
  75 The @option{-enable-hax} option has been replaced by @option{-accel hax}.
  76 Both options have been introduced in QEMU version 2.9.0.
  77
  78 @subsection -drive file=json:@{...@{'driver':'file'@}@} (since 3.0)
  79
  80 The 'file' driver for drives is no longer appropriate for character or host
  81 devices and will only accept regular files (S_IFREG). The correct driver
  82 for these file types is 'host_cdrom' or 'host_device' as appropriate.
  83
  84 @subsection -net ...,name=@var{name} (since 3.1)
  85
  86 The @option{name} parameter of the @option{-net} option is a synonym
  87 for the @option{id} parameter, which should now be used instead.
  88
  89 @subsection -smp (invalid topologies) (since 3.1)
  90
  91 CPU topology properties should describe whole machine topology including
  92 possible CPUs.
  93
  94 However, historically it was possible to start QEMU with an incorrect topology
  95 where @math{@var{n} <= @var{sockets} * @var{cores} * @var{threads} < @var{maxcpus}},
  96 which could lead to an incorrect topology enumeration by the guest.
  97 Support for invalid topologies will be removed, the user must ensure
  98 topologies described with -smp include all possible cpus, i.e.
  99   @math{@var{sockets} * @var{cores} * @var{threads} = @var{maxcpus}}.
 100
 101 @section QEMU Machine Protocol (QMP) commands
 102
 103 @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)
 104
 105 "autoload" parameter is now ignored. All bitmaps are automatically loaded
 106 from qcow2 images.
 107
 108 @subsection query-cpus (since 2.12.0)
 109
 110 The ``query-cpus'' command is replaced by the ``query-cpus-fast'' command.
 111
 112 @subsection query-cpus-fast "arch" output member (since 3.0.0)
 113
 114 The ``arch'' output member of the ``query-cpus-fast'' command is
 115 replaced by the ``target'' output member.
 116
 117 @section System emulator human monitor commands
 118
 119 @subsection The hub_id parameter of 'hostfwd_add' / 'hostfwd_remove' (since 3.1)
 120
 121 The @option{[hub_id name]} parameter tuple of the 'hostfwd_add' and
 122 'hostfwd_remove' HMP commands has been replaced by @option{netdev_id}.
 123
 124 @section System emulator devices
 125
 126 @subsection ivshmem (since 2.6.0)
 127
 128 The ``ivshmem'' device type is replaced by either the ``ivshmem-plain''
 129 or ``ivshmem-doorbell`` device types.
 130
 131 @subsection bluetooth (since 3.1)
 132
 133 The bluetooth subsystem is unmaintained since many years and likely bitrotten
 134 quite a bit. It will be removed without replacement unless some users speaks
 135 up at the @email{qemu-devel@@nongnu.org} mailing list with information about
 136 their usecases.
 137
 138 @section System emulator machines
 139
 140 @subsection pc-0.10 and pc-0.11 (since 3.0)
 141
 142 These machine types are very old and likely can not be used for live migration
 143 from old QEMU versions anymore. A newer machine type should be used instead.
 144
 145 @subsection prep (PowerPC) (since 3.1)
 146
 147 This machine type uses an unmaintained firmware, broken in lots of ways,
 148 and unable to start post-2004 operating systems. 40p machine type should be
 149 used instead.
 150
 151 @section Device options
 152
 153 @subsection Block device options
 154
 155 @subsubsection "backing": "" (since 2.12.0)
 156
 157 In order to prevent QEMU from automatically opening an image's backing
 158 chain, use ``"backing": null'' instead.
 159
 160 @subsubsection rbd keyvalue pair encoded filenames: "" (since 3.1.0)
 161
 162 Options for ``rbd'' should be specified according to its runtime options,
 163 like other block drivers.  Legacy parsing of keyvalue pair encoded
 164 filenames is useful to open images with the old format for backing files;
 165 These image files should be updated to use the current format.
 166
 167 Example of legacy encoding:
 168
 169 @code{json:@{"file.driver":"rbd", "file.filename":"rbd:rbd/name"@}}
 170
 171 The above, converted to the current supported format:
 172
 173 @code{json:@{"file.driver":"rbd", "file.pool":"rbd", "file.image":"name"@}}
 174
 175 @subsection vio-spapr-device device options
 176
 177 @subsubsection "irq": "" (since 3.0.0)
 178
 179 The ``irq'' property is obsoleted.