On Thu, Jan 17, 2013 at 11:28 PM, Michael Tokarev <m...@tls.msk.ru> wrote: > Hello. > > I was thinking about switching users from (old) qemu-kvm to (new) qemu, > and am trying to understand the difference and how to compensate for > them. > > So far we had several discussions about this topic, first of all > touching live migration ([1]), which is about different side, > and some mentioning the topic I'm trying to discuss as well, > for example [2]. > > But there were no discussions (iirc) about other ingredients. > > As far as I remember, qemu-kvm had quite some differences compared > with qemu, at least: > > -accel kvm,tcg > -cpu kvm64 (or kvm32?) > -kernel_irqchip (machine option) > > So, my question is, -- what to suggest to use when a user switches > from qemu-kvm to qemu now? > > I can try to come up with a compat script of some sort which will > try to translate old qemu-kvm command line to new qemu command line, > something like: > > exec qemu-system-x86_64 -machine accel=kvm:tcg,kernel_irqchip=on -cpu kvm64 > "$@"
This is what exactly what I planned on shipping as Gentoo's /usr/bin/qemu-kvm. Let me know what you decide to change and I'll match suit. > > (I'm not sure yet how to handle default_machine_options but that's > minor, the above is enough to demonstrate what I'm talking about). > This is assuming that later definitions will override earlier of > the same name. > > Is that enough or is there something else needed? > > Is explicit kernel_irqchip necessary? > > How to choose between -cpu kvm64 vs kvm32? > > Is this expected to work with libvirt, which tries to specify > everything explicitly? > > I can also try to check other options to see whenever things > like -enable-kvm (or -disable), -machine accel=, -cpu are > specified and omit corresponding parts, again, I'm not yet > sure if that's necessary. > > And as mentioned in [2], I'm not sure such a wrapper is > welcome generally, due to different reception of defaults > by different people. > > Comments? > > [1] http://patchwork.ozlabs.org/patch/205676/ > [2] https://patchwork.kernel.org/patch/1531761/ > > Thanks, > > /mjt > -- Doug Goldstein
