Bug 658467
| Summary: | kvm clock breaks migration result stability - for unit test propose | |||
|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Michael S. Tsirkin <mst> | |
| Component: | qemu-kvm | Assignee: | jason wang <jasowang> | |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> | |
| Severity: | medium | Docs Contact: | ||
| Priority: | low | |||
| Version: | 6.0 | CC: | flang, jasowang, juzhang, kcao, lihuang, michen, mkenneth, qzhang, tburke, virt-maint | |
| Target Milestone: | rc | |||
| Target Release: | 6.1 | |||
| Hardware: | Unspecified | |||
| OS: | Unspecified | |||
| Whiteboard: | ||||
| Fixed In Version: | qemu-kvm-0.12.1.2-2.188.el6 | Doc Type: | Bug Fix | |
| Doc Text: |
Cause:
Qemu-kvm would query the the value of kvmclock every time when user do savevm even the vm have been stopped.
Consequence:
This would cause the two sequent savevm after vm is stopped produce a two different result which breaks the unit-test of migration.
Fix:
Introduce a new kvmclock device and register a vm state change notifier to record when the kvmclock value is valid. And query and save the kvmclock only the valid flag is set.
Result:
Kvmclock section is stable for migration unit-test.
|
Story Points: | --- | |
| Clone Of: | ||||
| : | 662386 (view as bug list) | Environment: | ||
| Last Closed: | 2011-12-06 15:43:57 UTC | Type: | --- | |
| Regression: | --- | Mount Type: | --- | |
| Documentation: | --- | CRM: | ||
| Verified Versions: | Category: | --- | ||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | ||
| Cloudforms Team: | --- | Target Upstream Version: | ||
| Embargoed: | ||||
| Bug Depends On: | ||||
| Bug Blocks: | 580954, 662386, 743047 | |||
|
Description
Michael S. Tsirkin
2010-11-30 13:21:51 UTC
Michael/Jason, Just an update: I am working on it, and have patches that should be ready RSN. From your usecase perspective, could you please let me know the relevance/importance of each of the 3 items? As the patches are not ready yet, I don't know if it will be worth to separate this into different bugzillas or not. Maybe we should. Thanks! Fixing either 1 or 2 is most important for me. Upstream patch at: http://lists.gnu.org/archive/html/qemu-devel/2010-12/msg00443.html Setting conditional NAK upstream. This is under heavy discussion , and the end result is unclear. Hi,Mst/Jason Our qe don't very clear what's this issue really means? would you please explain and give qe a efficient way to reproduce and verify this issue? verified this issue with fixed version qemu-kvm-0.12.1.2-2.190.el6.x86_64 using steps as comment13 step: 1.boot guest which has kvmclock #/usr/libexec/qemu-kvm...-rtc base=localtime,clock=host,driftfix=slew 2.migrate -d tcp... Result: migrate successful,and the kvm clock result is stability and not clock drift. Above all,this issue has been fixed. verified this issue with fixed version qemu-kvm-0.12.1.2-2.190.el6.x86_64 kernel-2.6.32-198.el6.x86_64
Technical note added. If any revisions are required, please edit the "Technical Notes" field
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New Contents:
Cause:
Qemu-kvm would query the the value of kvmclock every time when user do savevm even the vm have been stopped.
Consequence:
This would cause the two sequent savevm after vm is stopped produce a two different result which breaks the unit-test of migration.
Fix:
Introduce a new kvmclock device and register a vm state change notifier to record when the kvmclock value is valid. And query and save the kvmclock only the valid flag is set.
Result:
Kvmclock section is stable for migration unit-test.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHSA-2011-1531.html |