docs/qdev-device-use.txt

   1 = How to convert to -device & friends =
   2
   3 === Specifying Bus and Address on Bus ===
   4
   5 In qdev, each device has a parent bus.  Some devices provide one or
   6 more buses for children.  You can specify a device's parent bus with
   7 -device parameter bus.
   8
   9 A device typically has a device address on its parent bus.  For buses
  10 where this address can be configured, devices provide a bus-specific
  11 property.  Examples:
  12
  13     bus         property name       value format
  14     PCI         addr                %x.%x    (dev.fn, .fn optional)
  15     I2C         address             %u
  16     SCSI        scsi-id             %u
  17     IDE         unit                %u
  18     HDA         cad                 %u
  19     virtio-serial-bus  nr           %u
  20     ccid-bus    slot                %u
  21     USB         port                %d(.%d)*    (port.port...)
  22
  23 Example: device i440FX-pcihost is on the root bus, and provides a PCI
  24 bus named pci.0.  To put a FOO device into its slot 4, use -device
  25 FOO,bus=/i440FX-pcihost/pci.0,addr=4.  The abbreviated form bus=pci.0
  26 also works as long as the bus name is unique.
  27
  28 === Block Devices ===
  29
  30 A QEMU block device (drive) has a host and a guest part.
  31
  32 In the general case, the guest device is connected to a controller
  33 device.  For instance, the IDE controller provides two IDE buses, each
  34 of which can have up to two devices, and each device is a guest part,
  35 and is connected to a host part.
  36
  37 Except we sometimes lump controller, bus(es) and drive device(s) all
  38 together into a single device.  For instance, the ISA floppy
  39 controller is connected to up to two host drives.
  40
  41 The old ways to define block devices define host and guest part
  42 together.  Sometimes, they can even define a controller device in
  43 addition to the block device.
  44
  45 The new way keeps the parts separate: you create the host part with
  46 -drive, and guest device(s) with -device.
  47
  48 The various old ways to define drives all boil down to the common form
  49
  50     -drive if=TYPE,bus=BUS,unit=UNIT,OPTS...
  51
  52 TYPE, BUS and UNIT identify the controller device, which of its buses
  53 to use, and the drive's address on that bus.  Details depend on TYPE.
  54
  55 Instead of bus=BUS,unit=UNIT, you can also say index=IDX.
  56
  57 In the new way, this becomes something like
  58
  59    -drive if=none,id=DRIVE-ID,HOST-OPTS...
  60    -device DEVNAME,drive=DRIVE-ID,DEV-OPTS...
  61
  62 The old OPTS get split into HOST-OPTS and DEV-OPTS as follows:
  63
  64 * file, format, snapshot, cache, aio, readonly, rerror, werror go into
  65   HOST-OPTS.
  66
  67 * cyls, head, secs and trans go into HOST-OPTS.  Future work: they
  68   should go into DEV-OPTS instead.
  69
  70 * serial goes into DEV-OPTS, for devices supporting serial numbers.
  71   For other devices, it goes nowhere.
  72
  73 * media is special.  In the old way, it selects disk vs. CD-ROM with
  74   if=ide, if=scsi and if=xen.  The new way uses DEVNAME for that.
  75   Additionally, readonly=on goes into HOST-OPTS.
  76
  77 * addr is special, see if=virtio below.
  78
  79 The -device argument differs in detail for each type of drive:
  80
  81 * if=ide
  82
  83   -device DEVNAME,drive=DRIVE-ID,bus=IDE-BUS,unit=UNIT
  84
  85   where DEVNAME is either ide-hd or ide-cd, IDE-BUS identifies an IDE
  86   bus, normally either ide.0 or ide.1, and UNIT is either 0 or 1.
  87
  88 * if=scsi
  89
  90   The old way implicitly creates SCSI controllers as needed.  The new
  91   way makes that explicit:
  92
  93   -device lsi53c895a,id=ID
  94
  95   As for all PCI devices, you can add bus=PCI-BUS,addr=DEVFN to
  96   control the PCI device address.
  97
  98   This SCSI controller provides a single SCSI bus, named ID.0.  Put a
  99   disk on it:
 100
 101   -device DEVNAME,drive=DRIVE-ID,bus=ID.0,scsi-id=UNIT
 102
 103   where DEVNAME is either scsi-hd, scsi-cd or scsi-generic.
 104
 105 * if=floppy
 106
 107   -device floppy,unit=UNIT,drive=DRIVE-ID
 108
 109   Without any -device floppy,... you get an empty unit 0 and no unit
 110   1.  You can use -nodefaults to suppress the default unit 0, see
 111   "Default Devices".
 112
 113 * if=virtio
 114
 115   -device virtio-blk-pci,drive=DRIVE-ID,class=C,vectors=V,ioeventfd=IOEVENTFD
 116
 117   This lets you control PCI device class and MSI-X vectors.
 118
 119   IOEVENTFD controls whether or not ioeventfd is used for virtqueue
 120   notify.  It can be set to on (default) or off.
 121
 122   As for all PCI devices, you can add bus=PCI-BUS,addr=DEVFN to
 123   control the PCI device address.  This replaces option addr available
 124   with -drive if=virtio.
 125
 126 * if=pflash, if=mtd, if=sd, if=xen are not yet available with -device
 127
 128 For USB storage devices, you can use something like:
 129
 130     -device usb-storage,drive=DRIVE-ID,removable=RMB
 131
 132 The removable parameter gives control over the SCSI INQUIRY removable
 133 (RMB) bit.  USB thumbdrives usually set removable=on, while USB hard
 134 disks set removable=off.
 135
 136 Bug: usb-storage pretends to be a block device, but it's really a SCSI
 137 controller that can serve only a single device, which it creates
 138 automatically.  The automatic creation guesses what kind of guest part
 139 to create from the host part, like -drive if=scsi.  Host and guest
 140 part are not cleanly separated.
 141
 142 === Character Devices ===
 143
 144 A QEMU character device has a host and a guest part.
 145
 146 The old ways to define character devices define host and guest part
 147 together.
 148
 149 The new way keeps the parts separate: you create the host part with
 150 -chardev, and the guest device with -device.
 151
 152 The various old ways to define a character device are all of the
 153 general form
 154
 155     -FOO FOO-OPTS...,LEGACY-CHARDEV
 156
 157 where FOO-OPTS... is specific to -FOO, and the host part
 158 LEGACY-CHARDEV is the same everywhere.
 159
 160 In the new way, this becomes
 161
 162     -chardev HOST-OPTS...,id=CHR-ID
 163     -device DEVNAME,chardev=CHR-ID,DEV-OPTS...
 164
 165 The appropriate DEVNAME depends on the machine type.  For type "pc":
 166
 167 * -serial becomes -device isa-serial,iobase=IOADDR,irq=IRQ,index=IDX
 168
 169   This lets you control I/O ports and IRQs.
 170
 171 * -parallel becomes -device isa-parallel,iobase=IOADDR,irq=IRQ,index=IDX
 172
 173   This lets you control I/O ports and IRQs.
 174
 175 * -usbdevice braille doesn't support LEGACY-CHARDEV syntax.  It always
 176   uses "braille".  With -device, this useful default is gone, so you
 177   have to use something like
 178
 179   -device usb-braille,chardev=braille -chardev braille,id=braille
 180
 181 LEGACY-CHARDEV translates to -chardev HOST-OPTS... as follows:
 182
 183 * null becomes -chardev null
 184
 185 * pty, msmouse, wctablet, braille, stdio likewise
 186
 187 * vc:WIDTHxHEIGHT becomes -chardev vc,width=WIDTH,height=HEIGHT
 188
 189 * vc:<COLS>Cx<ROWS>C becomes -chardev vc,cols=<COLS>,rows=<ROWS>
 190
 191 * con: becomes -chardev console
 192
 193 * COM<NUM> becomes -chardev serial,path=COM<NUM>
 194
 195 * file:FNAME becomes -chardev file,path=FNAME
 196
 197 * pipe:FNAME becomes -chardev pipe,path=FNAME
 198
 199 * tcp:HOST:PORT,OPTS... becomes -chardev socket,host=HOST,port=PORT,OPTS...
 200
 201 * telnet:HOST:PORT,OPTS... becomes
 202   -chardev socket,host=HOST,port=PORT,OPTS...,telnet=on
 203
 204 * udp:HOST:PORT@LOCALADDR:LOCALPORT becomes
 205   -chardev udp,host=HOST,port=PORT,localaddr=LOCALADDR,localport=LOCALPORT
 206
 207 * unix:FNAME becomes -chardev socket,path=FNAME
 208
 209 * /dev/parportN becomes -chardev parport,file=/dev/parportN
 210
 211 * /dev/ppiN likewise
 212
 213 * Any other /dev/FNAME becomes -chardev tty,path=/dev/FNAME
 214
 215 * mon:LEGACY-CHARDEV is special: it multiplexes the monitor onto the
 216   character device defined by LEGACY-CHARDEV.  -chardev provides more
 217   general multiplexing instead: you can connect up to four users to a
 218   single host part.  You need to pass mux=on to -chardev to enable
 219   switching the input focus.
 220
 221 QEMU uses LEGACY-CHARDEV syntax not just to set up guest devices, but
 222 also in various other places such as -monitor or -net
 223 user,guestfwd=...  You can use chardev:CHR-ID in place of
 224 LEGACY-CHARDEV to refer to a host part defined with -chardev.
 225
 226 === Network Devices ===
 227
 228 Host and guest part of network devices have always been separate.
 229
 230 The old way to define the guest part looks like this:
 231
 232     -net nic,netdev=NET-ID,macaddr=MACADDR,model=MODEL,name=ID,addr=STR,vectors=V
 233
 234 The new way is -device:
 235
 236     -device DEVNAME,netdev=NET-ID,mac=MACADDR,DEV-OPTS...
 237
 238 DEVNAME equals MODEL, except for virtio you have to name the virtio
 239 device appropriate for the bus (virtio-net-pci for PCI), and for USB
 240 you have to use usb-net.
 241
 242 The old name=ID parameter becomes the usual id=ID with -device.
 243
 244 For PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control the PCI
 245 device address, as usual.  The old -net nic provides parameter addr
 246 for that, which is silently ignored when the NIC is not a PCI device.
 247
 248 For virtio-net-pci, you can control whether or not ioeventfd is used for
 249 virtqueue notify by setting ioeventfd= to on or off (default).
 250
 251 -net nic accepts vectors=V for all models, but it's silently ignored
 252 except for virtio-net-pci (model=virtio).  With -device, only devices
 253 that support it accept it.
 254
 255 Not all devices are available with -device at this time.  All PCI
 256 devices and ne2k_isa are.
 257
 258 Some PCI devices aren't available with -net nic, e.g. i82558a.
 259
 260 === Graphics Devices ===
 261
 262 Host and guest part of graphics devices have always been separate.
 263
 264 The old way to define the guest graphics device is -vga VGA.  Not all
 265 machines support all -vga options.
 266
 267 The new way is -device.  The mapping from -vga argument to -device
 268 depends on the machine type.  For machine "pc", it's:
 269
 270     std         -device VGA
 271     cirrus      -device cirrus-vga
 272     vmware      -device vmware-svga
 273     qxl         -device qxl-vga
 274     none        -nodefaults
 275                 disables more than just VGA, see "Default Devices"
 276
 277 As for all PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control
 278 the PCI device address.
 279
 280 -device VGA supports properties bios-offset and bios-size, but they
 281 aren't used with machine type "pc".
 282
 283 For machine "isapc", it's
 284
 285     std         -device isa-vga
 286     cirrus      not yet available with -device
 287     none        -nodefaults
 288                 disables more than just VGA, see "Default Devices"
 289
 290 Bug: the new way doesn't work for machine types "pc" and "isapc",
 291 because it violates obscure device initialization ordering
 292 constraints.
 293
 294 === Audio Devices ===
 295
 296 Host and guest part of audio devices have always been separate.
 297
 298 The old way to define guest audio devices is -soundhw C1,...
 299
 300 The new way is to define each guest audio device separately with
 301 -device.
 302
 303 Map from -soundhw sound card name to -device:
 304
 305     ac97        -device AC97
 306     cs4231a     -device cs4231a,iobase=IOADDR,irq=IRQ,dma=DMA
 307     es1370      -device ES1370
 308     gus         -device gus,iobase=IOADDR,irq=IRQ,dma=DMA,freq=F
 309     hda         -device intel-hda,msi=MSI -device hda-duplex
 310     sb16        -device sb16,iobase=IOADDR,irq=IRQ,dma=DMA,dma16=DMA16,version=V
 311     adlib       not yet available with -device
 312     pcspk       not yet available with -device
 313
 314 For PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control the PCI
 315 device address, as usual.
 316
 317 === USB Devices ===
 318
 319 The old way to define a virtual USB device is -usbdevice DRIVER:OPTS...
 320
 321 The new way is -device DEVNAME,DEV-OPTS...  Details depend on DRIVER:
 322
 323 * ccid            -device usb-ccid
 324 * keyboard        -device usb-kbd
 325 * mouse           -device usb-mouse
 326 * tablet          -device usb-tablet
 327 * wacom-tablet    -device usb-wacom-tablet
 328 * braille         See "Character Devices"
 329
 330 === Watchdog Devices ===
 331
 332 Host and guest part of watchdog devices have always been separate.
 333
 334 The old way to define a guest watchdog device is -watchdog DEVNAME.
 335 The new way is -device DEVNAME.  For PCI devices, you can add
 336 bus=PCI-BUS,addr=DEVFN to control the PCI device address, as usual.
 337
 338 === Host Device Assignment ===
 339
 340 QEMU supports assigning host PCI devices (qemu-kvm only at this time)
 341 and host USB devices.  PCI devices can only be assigned with -device:
 342
 343     -device vfio-pci,host=ADDR,id=ID
 344
 345 To assign a host USB device use:
 346
 347     -device usb-host,hostbus=BUS,hostaddr=ADDR,vendorid=VID,productid=PRID
 348
 349 Omitted options match anything.
 350
 351 === Default Devices ===
 352
 353 QEMU creates a number of devices by default, depending on the machine
 354 type.
 355
 356 -device DEVNAME... and global DEVNAME... suppress default devices for
 357 some DEVNAMEs:
 358
 359     default device      suppressing DEVNAMEs
 360     CD-ROM              ide-cd, ide-drive, ide-hd, scsi-cd, scsi-hd
 361     floppy              floppy, isa-fdc
 362     parallel            isa-parallel
 363     serial              isa-serial
 364     VGA                 VGA, cirrus-vga, isa-vga, isa-cirrus-vga,
 365                         vmware-svga, qxl-vga, virtio-vga, ati-vga,
 366                         vhost-user-vga
 367
 368 The default NIC is connected to a default part created along with it.
 369 It is *not* suppressed by configuring a NIC with -device (you may call
 370 that a bug).  -net and -netdev suppress the default NIC.
 371
 372 -nodefaults suppresses all the default devices mentioned above, plus a
 373 few other things such as default SD-Card drive and default monitor.