To use SMP efficiently with Windows you need the ACPI Multiprocessor HAL profile. It seems you can only get it during the install if Windows detects that your HW fits that profile. The only solution I've found so far is to reinstall with ACPI enabled and make sure during install that the Multiprocessor HAL is selected.
The problem, in my case, is that virt-install did not enable ACPI even though I had asked it to do so.
I found a solution to the problem in Jaunty.
To use SMP efficiently with Windows you need the ACPI Multiprocessor HAL profile. It seems you can only get it during the install if Windows detects that your HW fits that profile. The only solution I've found so far is to reinstall with ACPI enabled and make sure during install that the Multiprocessor HAL is selected.
The problem, in my case, is that virt-install did not enable ACPI even though I had asked it to do so.