Bug#599200: base-installer: Install amd64 kernel on i686 kvm guest - and fail to boot
On Wed, Oct 06, 2010 at 12:53:04AM +0200, Petter Reinholdtsen wrote:
> [Lennart Sorensen]
> > Well try starting the kvm with '-cpu qemu32'. That should provide
> > the feature flags of a nice 32bit x86.
> I tried this by adding
> <cpu match='exact'>
> to the libvirtm XML file for the virtual machine, which caused '-cpu
> qemu32' to be part of the kvm command line. There is no GUI to add
> this in virt-manager, as far as I can see, so this will be out of
> reach for most users. No idea if this give hardware virtualization or
> software virtualization. The qemu part of the model name make me
> suspect the latter.
> Anyway, booting the virtual machine and looking at the CPU flags in
> cpuinfo, I can confirm that the lm flag is gone. I also tried with
> model=pentium3, and this too did not have the lm flag. This solve my
> imediate problem of testing the Debian Edu DVD, but do not address the
> problem for the unexpecting user of kvm.
Well it is certainly a bug in kvm. Of course most people probably run
a 64bit kernel these days, although I suppose many don't. kvm should
not tell the guest that the cpu supports something if kvm isn't capable
of supporting it.