Kernel panics when rebooting a 32bit Windows XP SP3 virtual guest. Following packages installed:

kernel.x86_64                         3.9.8-300.fc19            @updates        
kernel.x86_64                         3.9.9-301.fc19            @updates        
kernel-modules-extra.x86_64           3.9.8-300.fc19            @updates        
kernel-modules-extra.x86_64           3.9.9-301.fc19            @updates        
libvirt-daemon-driver-qemu.x86_64     1.0.5.2-1.fc19            @updates-testing
libvirt-daemon-kvm.x86_64             1.0.5.2-1.fc19            @updates-testing
libvirt-daemon-qemu.x86_64            1.0.5.2-1.fc19            @updates-testing
qemu.x86_64                           2:1.4.2-4.fc19            @updates-testing
qemu-common.x86_64                    2:1.4.2-4.fc19            @updates-testing
qemu-guest-agent.x86_64               2:1.4.2-4.fc19            @updates-testing
qemu-img.x86_64                       2:1.4.2-4.fc19            @updates-testing
qemu-kvm.x86_64                       2:1.4.2-4.fc19            @updates-testing
qemu-system-*.x86_64                  2:1.4.2-4.fc19            @updates-testing
qemu-user.x86_64                      2:1.4.2-4.fc19            @updates-testing


It is reproducible quite often. It has happened to me with kernels 3.9.8-300.fc19 and 3.9.9-301.fc19.

Photograph of the panic for kernel-3.9.8-300.fc19:
http://mbooth.fedorapeople.org/20130702_010246.jpg

Photograph of the panic for kernel-3.9.9-301.fc19:
http://mbooth.fedorapeople.org/20130708_121904.jpg