On 2012-05-22 07:34, Jan Kiszka wrote: > On 2012-05-22 07:04, Stefan Hajnoczi wrote: >> On Mon, May 21, 2012 at 5:54 PM, Erik Rull <webmas...@rdsoftware.de> wrote: >>> is there a summary existing that shows up the rough or actual differences >>> between qemu --enable-kvm and qemu-kvm? I tested both versions with the same >>> compile and start options, the CPU performance results are identical, only >>> the bootup time of my guest system with qemu-kvm seemed to be a bit faster >>> (not measured, it just feeled so). > > Current upstream does not enable the in-kernel irqchip of KVM by > default. This should explain the difference in boot-up times. Try > "-machine accel=kvm,kernel_irqchip=on". But the default will be on, just > like in qemu-kvm, once [1] is merged. > >> >> For production KVM instances I think it still makes sense to use >> qemu-kvm packages from your distro or qemu-kvm upstream source. >> >> Jan Kiszka has reduced the delta between qemu.git and qemu-kvm.git to >> the point where I think the list of differences is rather small - >> maybe PCI passthrough stuff, irqfd for vhost-net (which is now also >> being upstreamed into qemu.git), and a few other things I don't know >> of. > > Right, the list of differences is dramatically shrinking. As stated in > [2], soon only PCI passthrough and legacy interface dependencies on > qemu-kvm will be the remaining reasons to use it. If we are lucky, PCI > passthrough will also make it into upstream for QEMU 1.2, we are working > on this. > >> >> For development most patches should be against qemu.git unless they >> have a dependency on qemu-kvm.git code. > > Yes, unless you are working on the upstream merge itself, there is > practically no reason anymore to develop against qemu-kvm directly. > > Jan > > [1] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/91171 > [2] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/91026 >
I've added some more details on this to the QEMU wiki, see http://wiki.qemu.org/KVM. BTW, if someone could have a look at the VGA diffs and resolve them, that would be great. Gerd, what's the state of switching the BIOS? Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux