Use `-accel` instead of `-machine accel`
Currently libvirt uses -machine accel=kvm|tcg
under the hood, for <domain type='kvm|tcg'>
However, QEMU upstream recommends -accel kvm
. (Although, I admit, I don't know the precise reason why.)
Also, from a chat with Paolo Bonzini on #qemu, OFTC, a couple of quirks related the behavior of -machine accel
and -accel
:
-
Specifying
-accel
is incompatible with-machine accel
-
The command-line
-machine accel=kvm:tcg
is a shortcut to-accel kvm -accel tcg
(whereaccel=kvm:tcg
means "use if KVM is available, if not use TCG") -
However,
-machine accel=kvm -machine accel=tcg
is not the same as-accel kvm -accel tcg
— because:-machine accel=tcg
overwrites-machine accel=kvm
A related RFE: #229 (closed) ("RFE: Expose tb-size option for accel=tcg in qemu")