Bug 1085895

Summary:	Using Nested KVM freezes L0 host
Product:	[Fedora] Fedora	Reporter:	Rolf Fokkens <rolf>
Component:	kernel	Assignee:	fedora-kernel-kvm
Status:	CLOSED INSUFFICIENT_DATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	19	CC:	gansalmon, itamar, jonathan, jsiero, kernel-maint, madhu.chinakonda, mchehab
Target Milestone:	---
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-06-23 14:40:54 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Rolf Fokkens 2014-04-09 15:20:37 UTC

Description of problem:
While using nested KVM (to test ovirt) the L0 host freezes within a few hours. This happened two times, wich was 100% of the attempts.

Before using nested KVM the system was rock-solid, after using it the system has been rock-solid toow. 

Version-Release number of selected component (if applicable):
kernel-3.13.7-100.fc19.x86_64

How reproducible:
Create two Centos 6.5 virtual hosts, one running ovirt-engine, the other being a (virtual) ovirt node. Create a (nested) Fedora 20 VM in the ovirt node by starting the installation from downloadable F20 installation media.

Things will seem fine. But at a certain point, when you look the other way, it all comes to a grinding halt:
- no more keyboard (caps-lock-led) response
- black console (screensaver?) 

The only way out is a hard (L0) reset.

Steps to Reproduce:
1. Create two Centos 6.5 VM's (kernel-2.6.32-431) on a Fedora 19 system
2. Make one a ovirt-engine VM, and the other one a ovirt node
3. Create a nested F20 VM using ovirt
4. Wat a few hours
5. Freeze

Actual results:
Hard freeze of L0 host

Expected results:
Happily running L0, L1 and L2 VM's.

Additional info:
Motherboard: ASUS P8P67 PRO
CPU: Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
ovirt: 3.4.0-1

kvm_intel module parameters:

emulate_invalid_guest_state: Y
enable_apicv: N
enable_shadow_vmcs: N
ept: Y
eptad: N
fasteoi: Y
flexpriority: Y
nested: Y
ple_gap: 0
ple_window: 4096
unrestricted_guest: Y
vmm_exclusive: Y
vpid: Y

Comment 1 Justin M. Forbes 2014-05-21 19:30:49 UTC

*********** MASS BUG UPDATE **************

We apologize for the inconvenience.  There is a large number of bugs to go through and several of them have gone stale.  Due to this, we are doing a mass bug update across all of the Fedora 19 kernel bugs.

Fedora 19 has now been rebased to 3.14.4-100.fc19.  Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel.

If you have moved on to Fedora 20, and are still experiencing this issue, please change the version to Fedora 20.

If you experience different issues, please open a new bug report for those.

Comment 2 Justin M. Forbes 2014-06-23 14:40:54 UTC

*********** MASS BUG UPDATE **************
This bug is being closed with INSUFFICIENT_DATA as there has not been a response in 4 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.

Comment 3 Jasper Siero 2014-06-24 07:41:07 UTC

We updated the Fedora 19 L0 host with the latest updates a week ago. With the latest kernel 3.14.4-100.fc19.x86_64 we haven't experienced the problems anymore after running 7 days.