= How to convert to -device & friends = === Specifying Bus and Address on Bus === In qdev, each device has a parent bus. Some devices provide one or more buses for children. You can specify a device's parent bus with -device parameter bus. A device typically has a device address on its parent bus. For buses where this address can be configured, devices provide a bus-specific property. Examples: bus property name value format PCI addr %x.%x (dev.fn, .fn optional) I2C address %u SCSI scsi-id %u IDE unit %u HDA cad %u virtio-serial-bus nr %u ccid-bus slot %u USB port %d(.%d)* (port.port...) Example: device i440FX-pcihost is on the root bus, and provides a PCI bus named pci.0. To put a FOO device into its slot 4, use -device FOO,bus=/i440FX-pcihost/pci.0,addr=4. The abbreviated form bus=pci.0 also works as long as the bus name is unique. === Block Devices === A QEMU block device (drive) has a host and a guest part. In the general case, the guest device is connected to a controller device. For instance, the IDE controller provides two IDE buses, each of which can have up to two devices, and each device is a guest part, and is connected to a host part. Except we sometimes lump controller, bus(es) and drive device(s) all together into a single device. For instance, the ISA floppy controller is connected to up to two host drives. The old ways to define block devices define host and guest part together. Sometimes, they can even define a controller device in addition to the block device. The new way keeps the parts separate: you create the host part with -drive, and guest device(s) with -device. The various old ways to define drives all boil down to the common form -drive if=TYPE,bus=BUS,unit=UNIT,OPTS... TYPE, BUS and UNIT identify the controller device, which of its buses to use, and the drive's address on that bus. Details depend on TYPE. Instead of bus=BUS,unit=UNIT, you can also say index=IDX. In the new way, this becomes something like -drive if=none,id=DRIVE-ID,HOST-OPTS... -device DEVNAME,drive=DRIVE-ID,DEV-OPTS... The old OPTS get split into HOST-OPTS and DEV-OPTS as follows: * file, format, snapshot, cache, aio, readonly, rerror, werror go into HOST-OPTS. * cyls, head, secs and trans go into HOST-OPTS. Future work: they should go into DEV-OPTS instead. * serial goes into DEV-OPTS, for devices supporting serial numbers. For other devices, it goes nowhere. * media is special. In the old way, it selects disk vs. CD-ROM with if=ide, if=scsi and if=xen. The new way uses DEVNAME for that. Additionally, readonly=on goes into HOST-OPTS. * addr is special, see if=virtio below. The -device argument differs in detail for each type of drive: * if=ide -device DEVNAME,drive=DRIVE-ID,bus=IDE-BUS,unit=UNIT where DEVNAME is either ide-hd or ide-cd, IDE-BUS identifies an IDE bus, normally either ide.0 or ide.1, and UNIT is either 0 or 1. * if=scsi The old way implicitly creates SCSI controllers as needed. The new way makes that explicit: -device lsi53c895a,id=ID As for all PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control the PCI device address. This SCSI controller provides a single SCSI bus, named ID.0. Put a disk on it: -device DEVNAME,drive=DRIVE-ID,bus=ID.0,scsi-id=UNIT where DEVNAME is either scsi-hd, scsi-cd or scsi-generic. * if=floppy -device floppy,unit=UNIT,drive=DRIVE-ID Without any -device floppy,... you get an empty unit 0 and no unit 1. You can use -nodefaults to suppress the default unit 0, see "Default Devices". * if=virtio -device virtio-blk-pci,drive=DRIVE-ID,class=C,vectors=V,ioeventfd=IOEVENTFD This lets you control PCI device class and MSI-X vectors. IOEVENTFD controls whether or not ioeventfd is used for virtqueue notify. It can be set to on (default) or off. As for all PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control the PCI device address. This replaces option addr available with -drive if=virtio. * if=pflash, if=mtd, if=sd, if=xen are not yet available with -device For USB devices, the old way was actually different: -usbdevice disk:format=FMT:FILENAME "Was" because "disk:" is gone since v2.12.0. The old way provided much less control than -drive's OPTS... The new way fixes that: -device usb-storage,drive=DRIVE-ID,removable=RMB The removable parameter gives control over the SCSI INQUIRY removable (RMB) bit. USB thumbdrives usually set removable=on, while USB hard disks set removable=off. Bug: usb-storage pretends to be a block device, but it's really a SCSI controller that can serve only a single device, which it creates automatically. The automatic creation guesses what kind of guest part to create from the host part, like -drive if=scsi. Host and guest part are not cleanly separated. === Character Devices === A QEMU character device has a host and a guest part. The old ways to define character devices define host and guest part together. The new way keeps the parts separate: you create the host part with -chardev, and the guest device with -device. The various old ways to define a character device are all of the general form -FOO FOO-OPTS...,LEGACY-CHARDEV where FOO-OPTS... is specific to -FOO, and the host part LEGACY-CHARDEV is the same everywhere. In the new way, this becomes -chardev HOST-OPTS...,id=CHR-ID -device DEVNAME,chardev=CHR-ID,DEV-OPTS... The appropriate DEVNAME depends on the machine type. For type "pc": * -serial becomes -device isa-serial,iobase=IOADDR,irq=IRQ,index=IDX This lets you control I/O ports and IRQs. * -parallel becomes -device isa-parallel,iobase=IOADDR,irq=IRQ,index=IDX This lets you control I/O ports and IRQs. * -usbdevice braille doesn't support LEGACY-CHARDEV syntax. It always uses "braille". With -device, this useful default is gone, so you have to use something like -device usb-braille,chardev=braille -chardev braille,id=braille * -usbdevice serial::chardev is gone since v2.12.0. It became -device usb-serial,chardev=dev. LEGACY-CHARDEV translates to -chardev HOST-OPTS... as follows: * null becomes -chardev null * pty, msmouse, wctablet, braille, stdio likewise * vc:WIDTHxHEIGHT becomes -chardev vc,width=WIDTH,height=HEIGHT * vc:<COLS>Cx<ROWS>C becomes -chardev vc,cols=<COLS>,rows=<ROWS> * con: becomes -chardev console * COM<NUM> becomes -chardev serial,path=COM<NUM> * file:FNAME becomes -chardev file,path=FNAME * pipe:FNAME becomes -chardev pipe,path=FNAME * tcp:HOST:PORT,OPTS... becomes -chardev socket,host=HOST,port=PORT,OPTS... * telnet:HOST:PORT,OPTS... becomes -chardev socket,host=HOST,port=PORT,OPTS...,telnet=on * udp:HOST:PORT@LOCALADDR:LOCALPORT becomes -chardev udp,host=HOST,port=PORT,localaddr=LOCALADDR,localport=LOCALPORT * unix:FNAME becomes -chardev socket,path=FNAME * /dev/parportN becomes -chardev parallel,file=/dev/parportN * /dev/ppiN likewise * Any other /dev/FNAME becomes -chardev serial,path=/dev/FNAME * mon:LEGACY-CHARDEV is special: it multiplexes the monitor onto the character device defined by LEGACY-CHARDEV. -chardev provides more general multiplexing instead: you can connect up to four users to a single host part. You need to pass mux=on to -chardev to enable switching the input focus. QEMU uses LEGACY-CHARDEV syntax not just to set up guest devices, but also in various other places such as -monitor or -net user,guestfwd=... You can use chardev:CHR-ID in place of LEGACY-CHARDEV to refer to a host part defined with -chardev. === Network Devices === Host and guest part of network devices have always been separate. The old way to define the guest part looks like this: -net nic,netdev=NET-ID,macaddr=MACADDR,model=MODEL,name=ID,addr=STR,vectors=V Except for USB it looked like this: -usbdevice net:netdev=NET-ID,macaddr=MACADDR,name=ID "Looked" because "net:" is gone since v2.12.0. The new way is -device: -device DEVNAME,netdev=NET-ID,mac=MACADDR,DEV-OPTS... DEVNAME equals MODEL, except for virtio you have to name the virtio device appropriate for the bus (virtio-net-pci for PCI), and for USB you have to use usb-net. The old name=ID parameter becomes the usual id=ID with -device. For PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control the PCI device address, as usual. The old -net nic provides parameter addr for that, which is silently ignored when the NIC is not a PCI device. For virtio-net-pci, you can control whether or not ioeventfd is used for virtqueue notify by setting ioeventfd= to on or off (default). -net nic accepts vectors=V for all models, but it's silently ignored except for virtio-net-pci (model=virtio). With -device, only devices that support it accept it. Not all devices are available with -device at this time. All PCI devices and ne2k_isa are. Some PCI devices aren't available with -net nic, e.g. i82558a. === Graphics Devices === Host and guest part of graphics devices have always been separate. The old way to define the guest graphics device is -vga VGA. Not all machines support all -vga options. The new way is -device. The mapping from -vga argument to -device depends on the machine type. For machine "pc", it's: std -device VGA cirrus -device cirrus-vga vmware -device vmware-svga qxl -device qxl-vga none -nodefaults disables more than just VGA, see "Default Devices" As for all PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control the PCI device address. -device VGA supports properties bios-offset and bios-size, but they aren't used with machine type "pc". For machine "isapc", it's std -device isa-vga cirrus not yet available with -device none -nodefaults disables more than just VGA, see "Default Devices" Bug: the new way doesn't work for machine types "pc" and "isapc", because it violates obscure device initialization ordering constraints. === Audio Devices === Host and guest part of audio devices have always been separate. The old way to define guest audio devices is -soundhw C1,... The new way is to define each guest audio device separately with -device. Map from -soundhw sound card name to -device: ac97 -device AC97 cs4231a -device cs4231a,iobase=IOADDR,irq=IRQ,dma=DMA es1370 -device ES1370 gus -device gus,iobase=IOADDR,irq=IRQ,dma=DMA,freq=F hda -device intel-hda,msi=MSI -device hda-duplex sb16 -device sb16,iobase=IOADDR,irq=IRQ,dma=DMA,dma16=DMA16,version=V adlib not yet available with -device pcspk not yet available with -device For PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control the PCI device address, as usual. === USB Devices === The old way to define a virtual USB device is -usbdevice DRIVER:OPTS... The new way is -device DEVNAME,DEV-OPTS... Details depend on DRIVER: * ccid -device usb-ccid * keyboard -device usb-kbd * mouse -device usb-mouse * tablet -device usb-tablet * wacom-tablet -device usb-wacom-tablet * u2f -device u2f-{emulated,passthru} * braille See "Character Devices" Until v2.12.0, we additionally had * host:... See "Host Device Assignment" * disk:... See "Block Devices" * serial:... See "Character Devices" * net:... See "Network Devices" === Watchdog Devices === Host and guest part of watchdog devices have always been separate. The old way to define a guest watchdog device is -watchdog DEVNAME. The new way is -device DEVNAME. For PCI devices, you can add bus=PCI-BUS,addr=DEVFN to control the PCI device address, as usual. === Host Device Assignment === QEMU supports assigning host PCI devices (qemu-kvm only at this time) and host USB devices. PCI devices can only be assigned with -device: -device vfio-pci,host=ADDR,id=ID The old way to assign a USB host device -usbdevice host:auto:BUS.ADDR:VID:PRID was removed in v2.12.0. Any of BUS, ADDR, VID, PRID could be the wildcard *. The new way is -device usb-host,hostbus=BUS,hostaddr=ADDR,vendorid=VID,productid=PRID Omitted options match anything. === Default Devices === QEMU creates a number of devices by default, depending on the machine type. -device DEVNAME... and global DEVNAME... suppress default devices for some DEVNAMEs: default device suppressing DEVNAMEs CD-ROM ide-cd, ide-hd, scsi-cd, scsi-hd floppy floppy, isa-fdc parallel isa-parallel serial isa-serial VGA VGA, cirrus-vga, isa-vga, isa-cirrus-vga, vmware-svga, qxl-vga, virtio-vga, ati-vga, vhost-user-vga The default NIC is connected to a default part created along with it. It is *not* suppressed by configuring a NIC with -device (you may call that a bug). -net and -netdev suppress the default NIC. -nodefaults suppresses all the default devices mentioned above, plus a few other things such as default SD-Card drive and default monitor.