On Thu, Sep 20, 2007 at 10:45:03AM +0200, Gerd Hoffmann wrote: > Daniel P. Berrange wrote: > > Before starting any guest, the QEMU driver needs to figure out what version > > of QEMU is in use & thus determine whether it supports particular command > > line flags. We currently do that just by calling /usr/bin/qemu, since all > > the various qemu-system-XXX binaries share the same syntax. The only problem > > is that qemu-kvm does not neccessarily match the version of qemu installed. > > So we detect QEMU version 0.8.2, but KVM is 0.9.0 based. The result is that > > we pass the wrong style VNC argument to KVM & it fails to start. The second > > problem is that even if you only ever want to run KVM guests, you still have > > to have KVM itself installed. > > We have the same problem if the domain.xml has > "<emulator>/path/to/qemu-foo</emulator>" specified, which I think isn't > addressed by this patch ... Nope it is not addressed. I think maybe instead of detecting once for QEMU and KVM for the QEMU driver as whole, I'll move the flags into the per-VM data structure. This will have extra overhead, since for each distinct VM we'll have todo a test launch of QEMU, but VM creation is not a performance bottleneck so I don't think its an issue.