Feature #12734
bhyve on AMD should report SVM as disabled
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Description
Upstreaming OS-8008 from SmartOS:
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.
Related issues
Updated by Patrick Mooney 8 months ago
This was missed in the commit list for #12665 and has already been imported there.