Bug 637180
| Summary: | watchdog timer isn't reset when qemu resets | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Richard W.M. Jones <rjones> |
| Component: | qemu-kvm | Assignee: | Richard W.M. Jones <rjones> |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> |
| Severity: | medium | Docs Contact: | |
| Priority: | low | ||
| Version: | 6.1 | CC: | chayang, dallan, khong, lihuang, michen, mkenneth, shu, virt-maint |
| Target Milestone: | rc | ||
| Target Release: | 6.1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | qemu-kvm-0.12.1.2-2.134.el6 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2011-05-19 11:34:42 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, 634607 | ||
Patch posted upstream: http://lists.nongnu.org/archive/html/qemu-devel/2010-09/msg01754.html Fixed (eventually) upstream in the following commits: http://www.qemu.com/qemu.git/commit/?id=36888c6335422f07bbc50bf3443a39f24b90c7c6 Watchdog: disable watchdog timer when hard-rebooting a guest. http://www.qemu.com/qemu.git/commit/?id=fa82e9c300df6f7b8bd44a26ac752c4ea5da02c1 wdt_i6300esb: register a reset function (Note that both patches are needed) Reproduced on qemu-kvm-0.12.1.2-2.131.el6 as following steps. Reproduce Procedure: --------------------- 1. boot guest with "-watchdog i6300esb -watchdog-action reset" 2. in the guest, enable watchdog: #cat /dev/watchdog 3. reboot guest using following commands before watch dog heartbeat expire: #sync #echo 1 > /proc/sys/kernel/sysrq #echo b > /proc/sysrq-trigger 4. enter grub interface, press ESC to interrupt the timer, and wait. Actual results: ---------------- After step 4, for a few seconds, the guest reset. Verify this bug on qemu-kvm-0.12.1.2-2.146.el6 as the same steps above. Actual results: ---------------- After step 4, the guest stay in grub interface without reset. Conclusion: ------------- According to above results, this bug has been resolved. Should this be moved to VERIFIED now? Based on comment#9, change status to verified. An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0534.html An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0534.html |
Description of problem: The IB700 and I6300ESB watchdog timers don't include a handler to reset them when the VM / qemu is reset. The could lead to a failure case as follows: (a) guest boots, watchdog is enabled (b) guest does a reset eg: echo 'b' > /proc/sysrq-trigger (note that an ordinary /sbin/reboot wouldn't hit this case since that would properly disable the watchdog) (c) the reboot takes longer than the remaining time on the watchdog (d) the watchdog therefore fires during the reboot (e) probably the VM would just reboot again at this point which is pretty benign, but it could depend on the action that the user had selected for the watchdog Version-Release number of selected component (if applicable): All versions of qemu including upstream. How reproducible: Always. Steps to Reproduce: For the purpose of this demonstration, I'm going to directly invoke qemu-kvm. You need a guest with the watchdog daemon installed and configured. The guest should also have a grub timeout so you can interrupt the boot. (1) Run: qemu-kvm \ -enable-kvm \ -m 1024 -vnc :11 \ -drive file=watchdog-guest.img \ -watchdog i6300esb \ -watchdog-action reset (2) Wait until this boots, check watchdog daemon is running. (3) Inside the guest do: sync echo 1 > /proc/sys/kernel/sysrq echo b > /proc/sysrq-trigger Guest will immediately reboot. Same qemu process will still be running. (4) Enter grub as the guest boots (ie. hit Esc), and wait for a few seconds. Actual results: The watchdog will fire, causing the guest to reboot again while you are waiting in grub. Expected results: Watchdog should have been reset by the action of resetting qemu. Additional info: