** Description changed:
+ ===============================================
+ SRU Justification:
+ 1. Impact: libvirt-qemu guest crashes
+ 2. Development fix: refuse attempt to hotplug a new cpu
+ 3. Stable fix: same as development fix
+ 4. Test case:
+ a. create a vdisk: qemu-img create disk.img 1G
+ b. start a qemu instance: kvm -vnc :1 -monitor stdio -hda disk.img
+ c. in the monitor on stdio, add a cpu:
+ cpu_set 2 online
+ Without this patch, kvm will print an error and die. With the patch, it
+ will continue to run.
+ 5. Regression potential: since in fact there is an error (no new cpu was
+ hotplugged) and userspace gets no indication of this, this could
+ theoretically be a problem.
+ ===============================================
+
I'm using a Natty host and an Oneiric guest (both fully up to date) to
do some KVM testing. Hot plugging a CPU like this :
virsh setvcpus oneiric --count 2 --live
generates the following messages in /var/log/libvirt/qemu/oneiric.log :
kvm: /build/buildd/qemu-kvm-0.14.0+noroms/hw/qdev.c:95:
qdev_create_from_info: Assertion `bus->allow_hotplug' failed.
2011-10-19 14:32:53.124: shutting down
From there, obviously the guest dies.
Host details :
$ apt-cache policy qemu-kvm
qemu-kvm:
- Installed: 0.14.0+noroms-0ubuntu4.4
- Candidate: 0.14.0+noroms-0ubuntu4.4
- Version table:
- *** 0.14.0+noroms-0ubuntu4.4 0
- 500 http://ca.archive.ubuntu.com/ubuntu/ natty-updates/main amd64
Packages
- 500 http://ca.archive.ubuntu.com/ubuntu/ natty-security/main amd64
Packages
- 100 /var/lib/dpkg/status
- 0.14.0+noroms-0ubuntu4 0
- 500 http://ca.archive.ubuntu.com/ubuntu/ natty/main amd64 Packages
+ Installed: 0.14.0+noroms-0ubuntu4.4
+ Candidate: 0.14.0+noroms-0ubuntu4.4
+ Version table:
+ *** 0.14.0+noroms-0ubuntu4.4 0
+ 500 http://ca.archive.ubuntu.com/ubuntu/ natty-updates/main amd64
Packages
+ 500 http://ca.archive.ubuntu.com/ubuntu/ natty-security/main amd64
Packages
+ 100 /var/lib/dpkg/status
+ 0.14.0+noroms-0ubuntu4 0
+ 500 http://ca.archive.ubuntu.com/ubuntu/ natty/main amd64 Packages
$ apt-cache policy libvirt-bin
libvirt-bin:
- Installed: 0.8.8-1ubuntu6.6
- Candidate: 0.8.8-1ubuntu6.6
- Version table:
- *** 0.8.8-1ubuntu6.6 0
- 500 http://ca.archive.ubuntu.com/ubuntu/ natty-proposed/main amd64
Packages
- 100 /var/lib/dpkg/status
- 0.8.8-1ubuntu6.5 0
- 500 http://ca.archive.ubuntu.com/ubuntu/ natty-updates/main amd64
Packages
- 500 http://ca.archive.ubuntu.com/ubuntu/ natty-security/main amd64
Packages
- 0.8.8-1ubuntu6 0
- 500 http://ca.archive.ubuntu.com/ubuntu/ natty/main amd64 Packages
+ Installed: 0.8.8-1ubuntu6.6
+ Candidate: 0.8.8-1ubuntu6.6
+ Version table:
+ *** 0.8.8-1ubuntu6.6 0
+ 500 http://ca.archive.ubuntu.com/ubuntu/ natty-proposed/main amd64
Packages
+ 100 /var/lib/dpkg/status
+ 0.8.8-1ubuntu6.5 0
+ 500 http://ca.archive.ubuntu.com/ubuntu/ natty-updates/main amd64
Packages
+ 500 http://ca.archive.ubuntu.com/ubuntu/ natty-security/main amd64
Packages
+ 0.8.8-1ubuntu6 0
+ 500 http://ca.archive.ubuntu.com/ubuntu/ natty/main amd64 Packages
ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: qemu-kvm 0.14.0+noroms-0ubuntu4.4
ProcVersionSignature: Ubuntu 2.6.38-12.51-generic 2.6.38.8
Uname: Linux 2.6.38-12-generic x86_64
Architecture: amd64
Date: Wed Oct 19 14:30:44 2011
KvmCmdLine: Error: command ['ps', '-C', 'kvm', '-F'] failed with exit code 1:
UID PID PPID C SZ RSS PSR STIME TTY TIME CMD
MachineType: LENOVO 2516CTO
ProcEnviron:
- LANGUAGE=en_US:en
- LANG=en_US.UTF-8
- SHELL=/bin/bash
+ LANGUAGE=en_US:en
+ LANG=en_US.UTF-8
+ SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-2.6.38-12-generic
root=/dev/mapper/vg0-root ro possible_cpus=4 swapaccount=0 nodelayacct
pcie_aspm=force splash vt.handoff=7
SourcePackage: qemu-kvm
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/20/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 6IET78WW (1.38 )
dmi.board.name: 2516CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias:
dmi:bvnLENOVO:bvr6IET78WW(1.38):bd05/20/2011:svnLENOVO:pn2516CTO:pvrThinkPadT410:rvnLENOVO:rn2516CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2516CTO
dmi.product.version: ThinkPad T410
dmi.sys.vendor: LENOVO
** Also affects: libvirt (Ubuntu Oneiric)
Importance: Undecided
Status: New
** Also affects: qemu-kvm (Ubuntu Oneiric)
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/878422
Title:
CPU hot plug kills the guest
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