On Mon, Jun 25, 2018 at 08:26:28PM +0200, Paolo Bonzini wrote: > On 25/06/2018 19:30, Eduardo Habkost wrote: > >>> Attentive distros could even replace the wrapper script by a link. > >> If they are okay with replacing the "KVM only" semantics with "KVM or > >> TCG", which I think is generally worse. > > > > If we can't get agreement on what's the right default for each > > QEMU binary, I think that's yet another reason to document that > > upstream QEMU won't guarantee ABI compatibility if -accel is > > omitted. > > Before that we should ask what the benefit is in changing the default > for qemu-system-*. Nobody is using it in practice to start QEMU with > KVM enabled...
How can you be sure? If qemu-system-* is installed with KVM compiled in, libvirt will probe it using "-machine none,accel=kvm:tcg" and run the VM using "-machine $MACHINE,accel=kvm". In either case, I'm not arguing (yet) for changing the default upstream. I'm just arguing for upstream QEMU to not make any promises about the default. -- Eduardo
