Bug 881579

Summary: kernel-3.6.7-4 causes panic on FreeBSD KVM guest with >1 CPU
Product: [Fedora] Fedora Reporter: Karli Sjöberg <karli.sjoberg>
Component: kernelAssignee: Marcelo Tosatti <mtosatti>
Status: CLOSED INSUFFICIENT_DATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 17CC: gansalmon, itamar, joe, jonathan, kernel-maint, madhu.chinakonda, tburke
Target Milestone: ---   
Target Release: ---   
Hardware: Unspecified   
OS: FreeBSD   
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2013-05-28 10:39:54 EDT Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Description Karli Sjöberg 2012-11-29 01:49:26 EST
Description of problem:
Since recently patching our oVirt Hosts, I´ve been having trouble running FreeBSD guests with more than one virtual core or socket. I have managed to take a screenshot of how it looks like when it panics when booting kernel, right after ACPI:

I´ve tried this with similar results using 8.2-RELEASE, 8.3-RELEASE, 9.0-RELEASE and 9-STABLE.

If I edit the guest to have only one virtual core or socket, it boots up without issue.

This issue does not present itself when using a lower version kernel, works with kernel-3.3.4-5.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Have kernel-3.3.4-5 and a FreeBSD guest with >1 CPU
2. Update to kernel-3.6.7-4
Actual results:

Expected results:
Successful boot

Additional info:
Comment 1 Marcelo Tosatti 2012-12-12 21:03:29 EST

Thanks for the report, there should be a resolution soon.
Comment 2 Marcelo Tosatti 2012-12-17 21:17:07 EST

Can you load the kvm-intel.ko module with emulate_invalid_guest_state parameter set 
as 0, ie:

arch/x86/kvm/kvm-intel.ko emulate_invalid_guest_state=0
Comment 3 Marcelo Tosatti 2012-12-18 20:28:33 EST
Its very likely the cause for this are instruction emulation upstream (emulation of invalid guest state by default).

These are being fixed upstream. Once that is completed, it will be necessary to backport
to FC17.

In the meantime, loading kvm-intel.ko with emulate_invalid_guest_state=0 should work around the problem (tested locally on kvm.git as of dec/2012).
Comment 4 Marcelo Tosatti 2012-12-18 20:29:05 EST
(In reply to comment #3)
> Its very likely the cause for this are instruction emulation upstream
> (emulation of invalid guest state by default).

"instruction emulation changes upstream".
Comment 5 Josh Boyer 2013-05-28 10:39:54 EDT
This bug is being closed with INSUFFICIENT_DATA as there has not been a response in 2 weeks. If you are still experiencing this issue, please reopen and attach the relevant data from the latest kernel you are running and any data that might have been requested previously.