[Fedora-xen] f10 x86_64 xen VM guests fail to boot on f8 host

[Jon Swanson]

This is a cross post of the same subject on the Fedora Forums.  If this
is bad practice let me know and i'll never do it again.

Additional log info is available at
http://forums.fedoraforum.org/showthread.php?p=1149972&posted=1#post1149
972

I have two machines running fresh installs of f8 with the xen. Kernel
and all software versions are the same on both.
Specifically:



[root at machineA boot]# uname -a
Linux machineA 2.6.21.7-5.fc8xen #1 SMP Thu Aug 7 12:44:22 EDT 2008
x86_64 x86_64 x86_64 GNU/Linux
[root at machineA boot]# virsh version
Compiled against library: libvir 0.4.4
Using library: libvir 0.4.4
Using API: Xen 3.0.1
Running hypervisor: Xen 3.1.0

And:

[root at machineB ~]# uname -a
Linux machineB 2.6.21.7-5.fc8xen #1 SMP Thu Aug 7 12:44:22 EDT 2008
x86_64 x86_64 x86_64 GNU/Linux
[root at machineB ~]# virsh version
Compiled against library: libvir 0.4.4
Using library: libvir 0.4.4
Using API: Xen 3.0.1
Running hypervisor: Xen 3.1.0
MachineA has two AMD Opteron 275s. MachineB has four Intel(R) Xeon(TM)
CPU 2.80GHz processors.

Both machines are as up to date as possible.

I can boot or create x86_64 f10 guests on MachineA with no trouble
whatsoever.

MachineB will not boot/create x86_64 f10 guests.

The configuration files are created in the same manner, but as soon as
Xen tries to unpause the newly created domain, it crashes pretty much
instantly.



/var/log/xen/xend.log relevant output:

[2009-01-16 14:45:32 4120] DEBUG (DevController:150) Waiting for devices
vtpm.
[2009-01-16 14:45:32 4120] INFO (XendDomain:1130) Domain f10testB (21)
unpaused.
[2009-01-16 14:45:32 4120] WARNING (XendDomainInfo:1203) Domain has
crashed: name=f10testB id=21.
[2009-01-16 14:45:32 4120] DEBUG (XendDomainInfo:1802)
XendDomainInfo.destroy: domid=21
[2009-01-16 14:45:32 4120] DEBUG (XendDomainInfo:1821)
XendDomainInfo.destroyDomain(21)
I've also tried moving a functional guest from MachineA to MachineB to
boot it there, with the same results. Guest will not boot on MachineB.

f8 64bit guests will boot on MachineB with no problems.
f10 32bit guests will boot on MachineB with no problems.

Only 64bit machines seem to be borked.

Any information / help / insight as to why this is happening would be
very much appreciated. The machines are pretty similar, and since the
guests are paravirtualized it does not really make sense for the
processors to be the cause of the problem.

Thanks,
jon