"-machine [type=]name[,prop[=value][,...]]\n"
" selects emulated machine ('-machine help' for list)\n"
" property accel=accel1[:accel2[:...]] selects accelerator\n"
- " supported accelerators are kvm, xen, hax, hvf, nvmm, whpx or tcg (default: tcg)\n"
+ " supported accelerators are kvm, xen, hvf, nvmm, whpx or tcg (default: tcg)\n"
" vmport=on|off|auto controls emulation of vmport (default: auto)\n"
" dump-guest-core=on|off include guest memory in a core dump (default=on)\n"
" mem-merge=on|off controls memory merge support (default: on)\n"
``accel=accels1[:accels2[:...]]``
This is used to enable an accelerator. Depending on the target
- architecture, kvm, xen, hax, hvf, nvmm, whpx or tcg can be available.
+ architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available.
By default, tcg is used. If there is more than one accelerator
specified, the next one is used if the previous one fails to
initialize.
DEF("accel", HAS_ARG, QEMU_OPTION_accel,
"-accel [accel=]accelerator[,prop[=value][,...]]\n"
- " select accelerator (kvm, xen, hax, hvf, nvmm, whpx or tcg; use 'help' for a list)\n"
+ " select accelerator (kvm, xen, hvf, nvmm, whpx or tcg; use 'help' for a list)\n"
" igd-passthru=on|off (enable Xen integrated Intel graphics passthrough, default=off)\n"
" kernel-irqchip=on|off|split controls accelerated irqchip support (default=on)\n"
" kvm-shadow-mem=size of KVM shadow MMU in bytes\n"
" split-wx=on|off (enable TCG split w^x mapping)\n"
" tb-size=n (TCG translation block cache size)\n"
" dirty-ring-size=n (KVM dirty ring GFN count, default 0)\n"
+ " eager-split-size=n (KVM Eager Page Split chunk size, default 0, disabled. ARM only)\n"
" notify-vmexit=run|internal-error|disable,notify-window=n (enable notify VM exit and set notify window, x86 only)\n"
" thread=single|multi (enable multi-threaded TCG)\n", QEMU_ARCH_ALL)
SRST
``-accel name[,prop=value[,...]]``
This is used to enable an accelerator. Depending on the target
- architecture, kvm, xen, hax, hvf, nvmm, whpx or tcg can be available. By
+ architecture, kvm, xen, hvf, nvmm, whpx or tcg can be available. By
default, tcg is used. If there is more than one accelerator
specified, the next one is used if the previous one fails to
initialize.
is disabled (dirty-ring-size=0). When enabled, KVM will instead
record dirty pages in a bitmap.
+ ``eager-split-size=n``
+ KVM implements dirty page logging at the PAGE_SIZE granularity and
+ enabling dirty-logging on a huge-page requires breaking it into
+ PAGE_SIZE pages in the first place. KVM on ARM does this splitting
+ lazily by default. There are performance benefits in doing huge-page
+ split eagerly, especially in situations where TLBI costs associated
+ with break-before-make sequences are considerable and also if guest
+ workloads are read intensive. The size here specifies how many pages
+ to break at a time and needs to be a valid block size which is
+ 1GB/2MB/4KB, 32MB/16KB and 512MB/64KB for 4KB/16KB/64KB PAGE_SIZE
+ respectively. Be wary of specifying a higher size as it will have an
+ impact on the memory. By default, this feature is disabled
+ (eager-split-size=0).
+
``notify-vmexit=run|internal-error|disable,notify-window=n``
Enables or disables notify VM exit support on x86 host and specify
the corresponding notify window to trigger the VM exit if enabled.
to honor this value but actual latencies may be lower or higher.
``-audiodev pipewire,id=id[,prop[=value][,...]]``
- Creates a backend using Pipewire. This backend is available on
+ Creates a backend using PipeWire. This backend is available on
most systems.
- Pipewire specific options are:
+ PipeWire specific options are:
``in|out.latency=usecs``
Desired latency in microseconds.
ERST
DEF("hda", HAS_ARG, QEMU_OPTION_hda,
- "-hda/-hdb file use 'file' as IDE hard disk 0/1 image\n", QEMU_ARCH_ALL)
+ "-hda/-hdb file use 'file' as hard disk 0/1 image\n", QEMU_ARCH_ALL)
DEF("hdb", HAS_ARG, QEMU_OPTION_hdb, "", QEMU_ARCH_ALL)
DEF("hdc", HAS_ARG, QEMU_OPTION_hdc,
- "-hdc/-hdd file use 'file' as IDE hard disk 2/3 image\n", QEMU_ARCH_ALL)
+ "-hdc/-hdd file use 'file' as hard disk 2/3 image\n", QEMU_ARCH_ALL)
DEF("hdd", HAS_ARG, QEMU_OPTION_hdd, "", QEMU_ARCH_ALL)
SRST
``-hda file``
``-hdc file``
\
``-hdd file``
- Use file as hard disk 0, 1, 2 or 3 image (see the :ref:`disk images`
- chapter in the System Emulation Users Guide).
+ Use file as hard disk 0, 1, 2 or 3 image on the default bus of the
+ emulated machine (this is for example the IDE bus on most x86 machines,
+ but it can also be SCSI, virtio or something else on other target
+ architectures). See also the :ref:`disk images` chapter in the System
+ Emulation Users Guide.
ERST
DEF("cdrom", HAS_ARG, QEMU_OPTION_cdrom,
- "-cdrom file use 'file' as IDE cdrom image (cdrom is ide1 master)\n",
+ "-cdrom file use 'file' as CD-ROM image\n",
QEMU_ARCH_ALL)
SRST
``-cdrom file``
- Use file as CD-ROM image (you cannot use ``-hdc`` and ``-cdrom`` at
- the same time). You can use the host CD-ROM by using ``/dev/cdrom``
- as filename.
+ Use file as CD-ROM image on the default bus of the emulated machine
+ (which is IDE1 master on x86, so you cannot use ``-hdc`` and ``-cdrom``
+ at the same time there). On systems that support it, you can use the
+ host CD-ROM by using ``/dev/cdrom`` as filename.
ERST
DEF("blockdev", HAS_ARG, QEMU_OPTION_blockdev,
" VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
" netmap device, defaults to '/dev/netmap')\n"
#endif
+#ifdef CONFIG_AF_XDP
+ "-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off]\n"
+ " [,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]\n"
+ " attach to the existing network interface 'name' with AF_XDP socket\n"
+ " use 'mode=MODE' to specify an XDP program attach mode\n"
+ " use 'force-copy=on|off' to force XDP copy mode even if device supports zero-copy (default: off)\n"
+ " use 'inhibit=on|off' to inhibit loading of a default XDP program (default: off)\n"
+ " with inhibit=on,\n"
+ " use 'sock-fds' to provide file descriptors for already open AF_XDP sockets\n"
+ " added to a socket map in XDP program. One socket per queue.\n"
+ " use 'queues=n' to specify how many queues of a multiqueue interface should be used\n"
+ " use 'start-queue=m' to specify the first queue that should be used\n"
+#endif
#ifdef CONFIG_POSIX
"-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
" configure a vhost-user network, backed by a chardev 'dev'\n"
#ifdef CONFIG_NETMAP
"netmap|"
#endif
+#ifdef CONFIG_AF_XDP
+ "af-xdp|"
+#endif
#ifdef CONFIG_POSIX
"vhost-user|"
#endif
#ifdef CONFIG_NETMAP
"netmap|"
#endif
+#ifdef CONFIG_AF_XDP
+ "af-xdp|"
+#endif
#ifdef CONFIG_VMNET
"vmnet-host|vmnet-shared|vmnet-bridged|"
#endif
" old way to initialize a host network interface\n"
" (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
SRST
-``-nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr][,model=mn]``
+``-nic [tap|bridge|user|l2tpv3|vde|netmap|af-xdp|vhost-user|socket][,...][,mac=macaddr][,model=mn]``
This option is a shortcut for configuring both the on-board
(default) guest NIC hardware and the host network backend in one go.
The host backend options are the same as with the corresponding
# launch QEMU instance
|qemu_system| linux.img -nic vde,sock=/tmp/myswitch
+``-netdev af-xdp,id=str,ifname=name[,mode=native|skb][,force-copy=on|off][,queues=n][,start-queue=m][,inhibit=on|off][,sock-fds=x:y:...:z]``
+ Configure AF_XDP backend to connect to a network interface 'name'
+ using AF_XDP socket. A specific program attach mode for a default
+ XDP program can be forced with 'mode', defaults to best-effort,
+ where the likely most performant mode will be in use. Number of queues
+ 'n' should generally match the number or queues in the interface,
+ defaults to 1. Traffic arriving on non-configured device queues will
+ not be delivered to the network backend.
+
+ .. parsed-literal::
+
+ # set number of queues to 4
+ ethtool -L eth0 combined 4
+ # launch QEMU instance
+ |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
+ -netdev af-xdp,id=n1,ifname=eth0,queues=4
+
+ 'start-queue' option can be specified if a particular range of queues
+ [m, m + n] should be in use. For example, this is may be necessary in
+ order to use certain NICs in native mode. Kernel allows the driver to
+ create a separate set of XDP queues on top of regular ones, and only
+ these queues can be used for AF_XDP sockets. NICs that work this way
+ may also require an additional traffic redirection with ethtool to these
+ special queues.
+
+ .. parsed-literal::
+
+ # set number of queues to 1
+ ethtool -L eth0 combined 1
+ # redirect all the traffic to the second queue (id: 1)
+ # note: drivers may require non-empty key/mask pair.
+ ethtool -N eth0 flow-type ether \\
+ dst 00:00:00:00:00:00 m FF:FF:FF:FF:FF:FE action 1
+ ethtool -N eth0 flow-type ether \\
+ dst 00:00:00:00:00:01 m FF:FF:FF:FF:FF:FE action 1
+ # launch QEMU instance
+ |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
+ -netdev af-xdp,id=n1,ifname=eth0,queues=1,start-queue=1
+
+ XDP program can also be loaded externally. In this case 'inhibit' option
+ should be set to 'on' and 'sock-fds' provided with file descriptors for
+ already open but not bound XDP sockets already added to a socket map for
+ corresponding queues. One socket per queue.
+
+ .. parsed-literal::
+
+ |qemu_system| linux.img -device virtio-net-pci,netdev=n1 \\
+ -netdev af-xdp,id=n1,ifname=eth0,queues=3,inhibit=on,sock-fds=15:16:17
+
``-netdev vhost-user,chardev=id[,vhostforce=on|off][,queues=n]``
Establish a vhost-user netdev, backed by a chardev id. The chardev
should be a unix domain socket backed one. The vhost-user uses a
projects / mirror_qemu.git / blobdiff