On Wed, Jan 06, 2010 at 10:38:32AM +0100, Jiri Denemark wrote:

...

If I specify

<cpu match="exact"> <model>qemu64</model> </cpu>

according to the new cpu schema, I get error: internal error guest CPU is not compatible with host CPU because qemu64 supports svm, and my host does not.

However, the error remains when I explicitly ask to disable svm with <feature policy="disable" name="svm"/>

I am not sure if this is a bug or an intended feature, but I'd expect cpu_disable taken into account when doing x86ModelCompare(host_model, cpu_require)

It is a bug. There's no sense in checking features which will be disabled anyway.

Thanks for reporting.

Only today was I told of another issue with specifying: <model>qemu64</model> <feature policy="disable" name="svm"/> libvirt's algorithm ends up setting -cpu qemu32,+lm,+nx,+syscall,+cx16,+ssse3,+clflush,+pse36,+mca,+mtrr which is quite different (particularily if you intend to run 64 bit guests), and certainly no what you'd expect with match="expect". Regards, Dan.