bhyve: Report SVM as disabled on AMD
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Authored by chuck on Jul 23 2025, 11:13 PM.

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Reviewers

markj
corvink
avg
jhb

Group Reviewers

bhyve

Commits

rG92dfc3fbcd79: bhyve: Report SVM as disabled on AMD

Summary

bhyve with a Windows 2025 guest will hang/freeze with the message

rdmsr to register 0xc0010114

on a system with an AMD Ryzen 5. Evidently, recent versions of Windows
ignore the CPUID bits and still read this MSR.

Fix is to report Secure Virtual Machine (SVM) mode as disabled in the VM CR.

PR: 288308
Reported by: demik+freebsd@lostwave.net
Tested by: demik+freebsd@lostwave.net
Obtained from: Illumos

Diff Detail

Repository

rG FreeBSD src repository

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Lint Not Applicable

Unit

Tests Not Applicable

Event Timeline

chuck created this revision.Jul 23 2025, 11:13 PM

Herald added subscribers: bcran, rgrimes, imp. · View Herald TranscriptJul 23 2025, 11:13 PM

chuck requested review of this revision.Jul 23 2025, 11:13 PM

Harbormaster completed remote builds in B65640: Diff 158961.Jul 23 2025, 11:13 PM

markj accepted this revision as: markj.Jul 24 2025, 12:43 PM

This revision is now accepted and ready to land.Jul 24 2025, 12:43 PM

avg accepted this revision.Jul 24 2025, 1:20 PM

jhb accepted this revision.Jul 25 2025, 6:51 PM

Closed by commit rG92dfc3fbcd79: bhyve: Report SVM as disabled on AMD (authored by chuck). · Explain WhyJul 26 2025, 11:12 PM

This revision was automatically updated to reflect the committed changes.

chuck added a commit: rG92dfc3fbcd79: bhyve: Report SVM as disabled on AMD.

Revision Contents
Changeset List

Path

Size

usr.sbin/

bhyve/

amd64/

xmsr.c

9 lines

Diff 159215

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usr.sbin/bhyve/amd64/xmsr.c

bhyve: Report SVM as disabled on AMDClosedPublicActions