|Priority:||4 - Normal|
|Created by:||Michael Zeller|
|Reported by:||Michael Zeller|
|Assigned to:||Michael Zeller|
Fixed: A fix for this issue is checked into the tree and tested.
(Resolution Date: 2019-10-23T16:30:58.374Z)
2019-10-24 Double Dip (Release Date: 2019-10-24)
As reported in https://github.com/joyent/smartos-live/issues/843 a Windows guest will hang at boot on AMD boxes without the "-w" command line flag (Ignore accesses to unimplemented Model Specific Registers).
Looking at this it seems Windows tries to read VM_CR MSR (C001_0114h).
rdmsr to register 0xc0010114 on vcpu 3
It seems that Windows ignores the cpuid bits here and attempts to poke the MSR anyways.
To test this change I ran a DEBUG platform with the change on our AMD Epyc lab box and confirmed I was able to boot a Windows bhyve instance without the "-w" flag. I also got confirmation that the user who reported the original issue was able to do the same on their hardware with the provided patched platform.
illumos-joyent commit c76cd14c4b928c713e29e8db8ad0889f08810f5d (branch master, by Mike Zeller)
OS-8008 bhyve on AMD should report SVM as disabled
Reviewed by: Patrick Mooney <email@example.com>
Reviewed by: Jason King <firstname.lastname@example.org>
Approved by: Jason King <email@example.com>