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VM Freezes when used CPU Passthrough

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I have managed to get a Windows 10 VM up and running however when I try and use CPU Passthrough the VM will not boot and actually locks up my Unraid Web GUI. I have to kill it from the console. If I used emulated CPU however, everything works fine. 


I have attached my diagnostics, if anyone has any idea as to why my CPU Passthrough isn't working that'd be great! The QEMU option works fine, but would like to see if pass-through helps in performance at all. 


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what guide did you follow in creating the vm? 90% of initial windows vm issues are due to people "winging" it and not following a guide. But I do not believe that to be the problem in this case.


you have this error:


2017-05-21 21:12:28.978+0000: 12072: error : x86FeatureInData:780 : internal error: unknown CPU feature __kvm_hv_spinlocks
2017-05-21 21:12:28.978+0000: 12072: error : x86FeatureInData:780 : internal error: unknown CPU feature __kvm_hv_vendor_id


which may be attributable to 


May 21 20:48:49 Tower kernel: TSC synchronization [CPU#0 -> CPU#1]:
May 21 20:48:49 Tower kernel: Measured 14831673997 cycles TSC warp between CPUs, turning off TSC clock.
May 21 20:48:49 Tower kernel: tsc: Marking TSC unstable due to check_tsc_sync_source failed


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I used the guide here: 




I had also set up a VM before Christmas that I had been running until recently. It started running slowly so I decided to rebuild from scratch (although I accidentally removed the config and image for that VM). 


I mean the VM runs fine using QEMU as opposed to just pass-through so I can live with it. But wasn't sure if I was missing something. I might try running the VM again this evening with less cores (I had been passing 8 cores through when it froze) 

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I am having a very similar issue myself as far as problem description goes with getting a Ubuntu VM stable.   My Windows 10 seems stable with CPU passthrough.  


I found this concerning the above error messages:




I decided that these were ok.   Seems the VM driver is interrogating the CPU to figure out what its capabilities are.



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  • 4 years later...

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