SMP on a Windows XP guest without a reinstall?

[graysky]

I just updated my Linux host to VB 3.0 which has support for SMP. I noticed that despite enabling this option (I have a quad core chip and have enabled all 4 cores in the virtual machine), my Windows XP VM only shows one core in its task manager. Does one have reinstall XP to the VM once SMP is enabled for the guest OS to detect it or is there a trick to getting the four cores to run in the guest without a reinstall?

Thanks!

[Perryg]

This is rather a touchy subject in Windows. You need to install the SMP kernel in Windows to make use of the SMP function. You also must have I/O-APIC on as well as have hardware-v turned on in the bios.

[Toitoine]

Hi,

In this howto, it is explained how to add a boot menu entry with the selection of the NT kernel

http://forums.virtualbox.org/viewtopic.php?f=2&t=9697

I've sucessfully boot XP in multiprocessor ACPI mode with that.

[Sasquatch]

When I upgraded my PC with a new processor, from single to dual core, I didn't need to change anything, Windows detected the new CPU directly and installed the SMP kernel without question. After a reboot, I had two cores available.
However, in this case, the CPU itself doesn't change, only the amount of cores. In that case, you need to change the kernel like Perry said. Open Device Manager and expand the Computer item. There you should see something like "ACPI Uniprocessor PC" or something. Update it's driver and say you want to manually choose one. You should now be able to pick the SMP driver for it. See the attached screenshots. It should work after this. I haven't, and can't, test this, as I don't have VB 3.0 installed yet, and have compatible hardware.

pick from list

screenshot9.png (27.46 KiB) Viewed 19608 times

pick one manually

screenshot10.png (29.6 KiB) Viewed 19591 times

select Multiprocessor

screenshot11.png (32.67 KiB) Viewed 19595 times

[tlu]

Open Device Manager and expand the Computer item. There you should see something like "ACPI Uniprocessor PC" or something. Update it's driver and say you want to manually choose one. You should now be able to pick the SMP driver for it.

This only applies to XP Pro. XP Home officially doesn't support multiprocessor systems. You can enable multiprocessor support by using this approach, though. It works for me.

[Sasquatch]

Right, I forgot about the crippled XP Home.

[borisprochazka]

Thanks for the nice description of how to get XP guest to use more then one CPU in VB, My problem is only that I don't get the "ACPI Multiprocessor PC" selection in the "Hardware Update Wizard". I only get "Advanced Configuration and Power Interface (ACPI) PC" (current) and "Standard PC" selections. Yes it's a WinXP Professional with SP3 and all the latest patches. Does any one have a clue on how to install the SMP kernel? I have the same problem with a Win2003R2 server.

[fixedwheel]

Does any one have a clue on how to install the SMP kernel?

do a search for HALu.zip => http://www.google.com/#&q=halu.zip+site ... ualbox.org