I do believe this question has been posted before not only here but on other Linux forums as well.
However I could not implement the solutions, I am probably missing something obvious.

KVM
Host: Fedora 23
1. Guest: Windows 10 UEFI
2. Guest: Windows 10 UEFI

Host machine has 3 GPU's plugged in and I have managed to pass two to the VM's, and that part works just fine. Although I did not manage to pass AMD cards to the VM's as the driver kept crashing the VM, the two nvidia cards I have now seam to work just fine without problems.

Now the problem is that on a Windows 10 VM, no matter what I do I can not get it to use more then one CPU core.

Tried configuring it via virt manager, tried editing the XML file, but no matter what, the VM uses only one core even though I can see more then one CPU in the Device manager on the VM.

Could anyone please help me out?

Thank you for your time.

It may depend on the Windows license.

Microsoft has been moving to a per core licensing model - and it won't use more than what the license says.

Are you serious? Well there is a reason I moved away from windows a long time ago.
At the moment I am using their trial version windows 10 but I ll go and see if I can use the one with the CD and see if it will work then.

You may not need to allocate cores to a vm. They are getting better about using resources. Just add in all that you have usually.

Anyway, I'd boot to a linux iso to see if you did in fact offer the client that you wanted to add. Also you may have to look at your host system for some settings that may affect this. Not all computers are defaulted with VM technologies enabled.

As jpollard notes, we don't know what you have in Windows 10. Some of the online web so called free versions will not support all hardware.

Okay I managed to fix it.

Solution 1: Have a licences windows 10 pro and it works just fine.

Note:
Linux guest does not have any of these problems, you can assign cores to it no problems

Also how stupid is it that the trial version does not include so many options, if you did not mention this to me it would have never occurred to me.

@jefro
There is nothing wrong with KVM and resource allocation it works like a charm with a Linux guest and host. The problem is windows licences as far as I could figure it out.

If I did not need a windows VM I would never even touch it.
Thank you so much for your time and effort.

As a last note - one of the few supercomputers (some years ago) could not make use of all the CPUs available in the hardware...

Turned out a Windows license manager stopped it.

Linux has no such artificial limitations, thus turned in a top 500 rating.

License problems are just one of the issues that pretty much killed Windows on supercomputers (cost is a big one).

I ran across this in one of the older (and no, I don't remember which one) top500 lists.

Try setting the processor topology to 1 socket, 2 cores. Your Windows license probably limits you to one socket, but should allow more than one core.

It is solved I just applied a licence key.

I've never had that issue on their server platforms. Install works with all cores.


Maybe some new feature to Windows 10?

Anyway, thanks for the update and solution.

There has always been limitations, with cheaper editions being limited to less RAM, CPU cores etc. https://www.microsoft.com/en-us/down...ldownloads_all

That's, btw, not only about the OS, MSSQL express, for example, is also limited to 4GB RAM and a single CPU core, you want more - pay up.

It is just another way to charge for no additional work.

http://arstechnica.com/information-t...ket-licensing/
http://www.networkworld.com/article/...rver-2012.html

I know there has always be limitations. The OP stated that only a single cpu was working until he applied license.

Even though I solved the problem with licences, I did call Microsoft in regard to this just to have an additional conformation, but they would not shed any light on the matter.

Anyway Windows 10 pro licence gave me the ability for a single socket and multiple core.
I ll go ahead and see if I can get my hands on 2012 R2 Windows server licence just to see if it will recognize more then then one socket by default from the topology of the KVM.

In addition I have been running 2 Windows 10 Pro VM on Fedora

Here are some of the problems that I have encountered, some of them I ve solved some of them still bug me.

1. EvilTouch graphics pad is good for productivity work but if you intend to play a game on a VM you will need either a USB pass-through of a mouse or a Generic USB mouse selected instead of an EvilTouch graphics pad.
Why?
In the the game unless you use one of the two stated options your mouse movement will be unpredictable and it will spin around.

2. Machines were going to sleep unexpectedly due to lack of disk space in the default location where the images were made.
Solution: Create the images there then move them to a diffrent location. That is what I did anyway.
Note: If you create the disk images outside of the default folder they are labelled to run in unconfined mode by SELINUX, when created in the default location they have a proper SELINUX label then.

3. SELINUX will prevent USB pass-though unless you either put it in permissive mode or configure SELINUX to allow for this to happen.



Current Problems:

1. Unable to get sound to work on the Windows VM's

2. Occasionally windows VM's crash and the entire gui crashes on the host system, in addition keyboard and mouse also freeze, the crash is unrecoverable and I have to perform a reboot of the host system. I suspect that it has something to do with the USB pass through and grabbing and releasing the USB mouse, from what I managed to conclude from the log files of libvirt.


Other then the stated everything else seams to work just fine.
I am able to run 2 VM's on a Fedora 23 host system and play games on both of them at the same time with pretty good FPS(50 min) on Ultra settings.

I know that it is perhaps a wrong place to ask but does any one have any experience with this sort of set up, at the moment I am trying to resolve these 2 issues and I am looking for custom solutions for GPU cooling to reduce the the overall space that the stock coolers take on the graphics cards so that I can attempt to plug two more in and see how that works out.

After I managed to get the most things working I ll make sure to make a video or a guide listing the steps for this set up and all the problems that I have encountered so that other people who use a sane, normal, secur and functional OS(LINUX) do not have to go about bashing their skulls against the wall in order to achieve this.

I'm running single socket and multiple cores just fine on a Windows 10 VM installed with a Windows 7 Home Premium product key. No "Pro" needed.

Windows 7 doesn't have the same restrictions that Windows 10 has.