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19.8. Expert Options

This section provides information about expert options.

KVM Virtualization

QEMU-KVM supports only KVM virtualization and it is used by default if available. If -enable-kvm is used and KVM is not available, qemu-kvm fails. However, if -enable-kvm is not used and KVM is not available, qemu-kvm runs in TCG mode, which is not supported.

Disable Kernel Mode PIT Reinjection


No Shutdown


No Reboot


Serial Port, Monitor, QMP

-serial <dev>
-monitor <dev>
-qmp <dev>
Supported devices are:
  • stdio - standard input/output
  • null - null device
  • file:<filename> - output to file.
  • tcp:[<host>]:<port>[,server][,nowait][,nodelay] - TCP Net console.
  • unix:<path>[,server][,nowait] - Unix domain socket.
  • mon:<dev_string> - Any device above, used to multiplex monitor too.
  • none - disable, valid only for -serial.
  • chardev:<id> - character device created with -chardev.

Monitor Redirect

-mon <chardev_id>[,mode=[readline|control]][,default=[on|off]]

Manual CPU Start



-rtc [base=utc|localtime|date][,clock=host|vm][,driftfix=none|slew]


-watchdog model

Watchdog Reaction

-watchdog-action <action>

Guest Memory Backing

-mem-prealloc -mem-path /dev/hugepages


-smbios type=0[,vendor=<str>][,<version=str>][,date=<str>][,release=%d.%d]
-smbios type=1[,manufacturer=<str>][,product=<str>][,version=<str>][,serial=<str>][,uuid=<uuid>][,sku=<str>][,family=<str>]