Even though I have an Intel Core2 Duo, it seems to not have virtualisation on chip:
http://www.intel.com/products/processor_number/chart/core2duo.htm
# virt-install -n hvm -r 128 --vcpus=1 -f /export/vms/hvm.dsk --vnc --vncport=5901 --hvm
Unsupported virtualization type
# psrinfo -vp
The physical processor has 2 virtual processors (0 1)
x86 (GenuineIntel 6FD family 6 model 15 step 13 clock 1667 MHz)
Intel(r) Core(tm)2 Duo CPU T5450 @ 1.66GHz
# isainfo -v
64-bit amd64 applications
ssse3 cx16 sse3 sse2 sse fxsr mmx cmov cx8 tsc fpu
32-bit i386 applications
ssse3 ahf cx16 sse3 sse2 sse fxsr mmx cmov cx8 tsc fpu
