[libvirt] Problems starting XEN HVM with libvirt

I've been having trouble getting a Xen HVM guest started using libvirt. I've tried Windows Vista, Fedora Core 8, and Fedora Core 6 guests. Domain 0 is FC 8. The only guest that starts correctly is the FC 6 guest. Has anyone else encountered something like this? Is there a master list of guest OS's that libvirt supports? Thanks -matthew CODE: #include <stdio.h> #include <libvirt/libvirt.h> #include <libvirt/virterror.h> const char* foo = "<domain type='xen'>" "<name>fc6</name>" "<os>" "<type>hvm</type>" "<loader>/usr/lib/xen/boot/hvmloader</loader>" "<boot dev='hd'/>" "</os>" "<memory>512000</memory>" "<vcpu>1</vcpu>" "<on_shutdown>shutdown</on_shutdown>" "<on_reboot>restart</on_reboot>" "<on_crash>restart</on_crash>" "<features>" "<pae/>" "<acpi/>" "<apic/>" "</features>" "<clock sync='localtime'/>" "<devices>" "<emulator>/usr/lib/xen/bin/qemu-dm</emulator>" "<disk type='block'>" "<source dev='/dev/vgvms/fc6_test'/>" "<target dev='hda'/>" "</disk>" "<interface type='ioemu'>" "<mac address='7A:AB:D0:01:82:98'/>" "</interface>" "<input type='tablet' bus='usb'/>" "<graphics type='sdl' password=''/>" "<serial type='pty'/>" "</devices>" "</domain>"; int main (int argc, char** argv) { virConnectPtr con; /* connection to the Xen hypervisor */ virDomainPtr domain; virInitialize(); con = virConnectOpen ("xen:///"); if (!con) { virErrorPtr err = virGetLastError (); printf ("virConnectOpen failed: %s\n", err->message); return -1; } domain = virDomainDefineXML (con, foo); if (!domain) { virErrorPtr err = virConnGetLastError (con); printf ("virDomainDefineXML failed: %s\n", err->message); } else { if (virDomainCreate (domain) < 0) { virErrorPtr err = virConnGetLastError (con); printf ("virDomainCreate failed: %s\n", err->message); } else { virDomainInfo info = {0}; virDomainGetInfo (domain, &info); printf ("state = %d\n", info.state); getchar (); } } virConnectClose (con); return 0; }