Hello,

I've had an older version of libvirtd/qemu running on Debian Lenny and had defined 4 virtual servers.
I have the kvm and kvm_intel modules loaded (also compiled from source). I copied over my 4 config
files from /etc/libvirt/qemu to /usr/local/etc/libvirt/qemu

Now when I start up libvirtd -v:

omega:~# libvirtd -v
20:17:38.877: warning : qemudStartup:566 : Unable to create cgroup for driver: No such device or address
libvir: Domain Config error : unknown OS type hvm
libvir: Domain Config error : unknown OS type hvm
libvir: Domain Config error : unknown OS type hvm
libvir: Domain Config error : unknown OS type hvm

I'm trying to make sense out of the config files at this point but not very successful at it. I googled around
a bit to see if others had this error message but most of the ones I found relate to not having the kernel
modules loaded, which is visible in the 'virsh capabilities' output. Mine shows:

fredl@omega:~$ which virsh
/usr/local/bin/virsh
fredl@omega:~$ virsh capabilities
<capabilities>

  <host>
    <cpu>
      <arch>x86_64</arch>
    </cpu>
    <migration_features>
      <live/>
      <uri_transports>
        <uri_transport>tcp</uri_transport>
      </uri_transports>
    </migration_features>
  </host>

</capabilities>

This seems odd, this is from my /proc/cpuinfo:

flags        : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology tsc_reliable nonstop_tsc aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse4_1 sse4_2 popcnt lahf_lm ida tpr_shadow vnmi flexpriority ept vpid

So the processor is capable of it, however:

fredl@omega:~$ virsh version
Compiled against library: libvir 0.7.1
Using library: libvir 0.7.1
Using API: QEMU 0.7.1
error: failed to get the hypervisor version
error: Unknown failure

I'm guessing that's the problem and I realized that in the Debian package the qemu binary is named 'kvm' (may be a symlink) while mine's in

-rwxr-xr-x 1 root staff 2286848 2009-09-26 19:31 /usr/local/bin/qemu-system-x86_64

So how does libvirtd try to find out the hypervisor version? how does it even know to use either Xen, qemu etc. ?