| Summary: | Race condition during virtio-blk dataplane stop triggers "Virtqueue size exceeded" | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Marcel Kolaja <mkolaja> |
| Component: | qemu-kvm-rhev | Assignee: | Stefan Hajnoczi <stefanha> |
| Status: | CLOSED ERRATA | QA Contact: | huiqingding <huding> |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | 7.2 | CC: | areis, chayang, huding, jen, jherrman, juzhang, knoel, lijin, mas-hatada, mrezanin, mst, stefanha, taosawa, virt-maint |
| Target Milestone: | rc | Keywords: | ZStream |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | qemu-kvm-rhev-2.3.0-31.el7_2.23 | Doc Type: | Bug Fix |
| Doc Text: |
Due to a race condition in the virtio-blk dataplane, live migration of a guest in some cases failed with a "Virtqueue size exceeded" error message. This update prevents the race condition from occurring, and thus allows live migration to work more reliably.
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Story Points: | --- |
| Clone Of: | 1378788 | Environment: | |
| Last Closed: | 2016-11-17 15:02:17 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Bug Depends On: | 1378788 | ||
| Bug Blocks: | |||
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Description
Marcel Kolaja
2016-09-29 09:45:20 UTC
Fix included in qemu-kvm-rhev-2.3.0-31.el7_2.23 I can reproduce this bug using win8 32 bits guest, when running CrystalDiskMark IO stress, migrate guest. Migration is failed with "Virtqueue size exceeded". But I cannot reproduce this bug using RHEL7.3 guest with fio as bz1378788 comment 0. Version-Release number of selected component (if applicable): qemu-kvm-rhev-2.3.0-31.el7_2.22 Reproduce steps: 1. Boot guest with virtio-blk-pci device in the source host -object iothread,id=thread0 -drive file=win8-32.raw,if=none,id=drive-ide0-0-0,format=raw,serial=mike_cao,cache=none -device virtio-blk-pci,iothread=thread0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 2. Boot guest in the destination host -object iothread,id=thread0 -drive file=win8-32.raw,if=none,id=drive-ide0-0-0,format=raw,serial=mike_cao,cache=none -device virtio-blk-pci,iothread=thread0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -incoming tcp:0:5800 3. Start CrystalDiskMark inside guest 4. Do migration Results: after step4, migration failed: source host: (qemu) qemu-kvm: Virtqueue size exceeded destination host: (qemu) qemu-kvm: Unknown combination of migration flags: 0 qemu-kvm: error while loading state section id 2(ram) qemu-kvm: load of migration failed: Invalid argument Test this bug using qemu-kvm-rhev-2.3.0-31.el7_2.23. Do test as comment #5, after step4, migration can be finished normally and guest works well in destination side. Do test as bz1378788 comment 0. Do 10+ times migration, migration is successful and the fio benchmark continues running in rhel7.2.z guest. 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. https://rhn.redhat.com/errata/RHBA-2016-2803.html |