Re: [Qemu-devel] Qemu the right way -[Subthread Cores]

[Andrew Randrianasulu]

> Since I do not have networking sorted out yet I cannot update win7 pro, and 
> it 
might be the updates which are needed for allowing more than two cpus.

hm, brief search on my side resulted in this tip:

https://answers.microsoft.com/en-us/windows/forum/windows_7-hardware/windows-7-professional-x64-only-showing-2-of-8/0155f525-df73-4642-a828-21b80d1564b0

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Some recommendations (in Windows, make sure you are running as Administrator):
 
- Run MSConfig -> Change to Boot tab -> Advanced Options -> "Number of 
Processors", make sure there is no check mark.
- Delete processor entries listed in Device Manager, then reboot.

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(I don't think BIOS options from this answer really apply directly to qemu case)

also, if win (or some applications inside it) keep crashing with -cpu host, you 
can try to reload host (Linux) kvm module with additional option:

"options kvm ignore_msrs=1" line (without quotes) should be added to
 /etc/modprobe.d/kvm.conf

from 
https://www.passmark.com/forum/performancetest/4748-startup-error-number-4-on-qemu-bsod