KVM SMP Linux Guests Hang on AMD
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Fix Released
|
Medium
|
Unassigned | ||
Lucid |
Fix Released
|
Medium
|
Stefan Bader |
Bug Description
Binary package hint: qemu-kvm
=======
SRU Justification
1. impact: KVM smp guests hang on AMD
2. how was the bug addressed: Two upstream commits (plus a third auxiliary) were re-implemented on lucid's kernel.
3. patch: see comment #27
4. TEST CASE: in lucid, on an AMD box, start a guest with '-smp 2'.
5. regression: Honestly this one scares me a bit because it was a tricky cherrypick, and affects timekeeping for all kvm users on x86 lucid. In theory timekeeping on guests could be adversely affected, or guests could fail to boot. However, guests have been tested on both AMD and intel hosts.
=======
SMP Linux guests are hanging under KVM. This does not happen always, but at least 50% of the time or so.
If I start the guests with "-smp 1" or just completely omit the "-smp" parameter this doesn't happen.
I can also say that it doesn't seem to happen on a Nehalem-based 8-core Xeon-based machine I've tried it on, but it does happen on both an AMD Phenom II 965 machine (the one this bug report is from) as well as an AMD Phenom II 1090T-based machine.
I am starting the VMs from the command line, manually running qemu-kvm with a command like the following:
qemu-system-x86_64 -m 1024 -smp 4 -cpu host -drive file=/var/
Additional Information:
Description: Ubuntu 10.04.2 LTS
Release: 10.04
qemu-kvm:
Installed: 0.12.3+
Candidate: 0.12.3+
Version table:
*** 0.12.3+
500 http://
100 /var/lib/
0.
500 http://
ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: qemu-kvm 0.12.3+
ProcVersionSign
Uname: Linux 2.6.32-28-server x86_64
Architecture: amd64
Date: Sun Feb 6 19:11:57 2011
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release amd64 (20100816.1)
KvmCmdLine: Error: command ['ps', '-C', 'kvm', '-F'] failed with exit code 1: UID PID PPID C SZ RSS PSR STIME TTY TIME CMD
MachineType: System manufacturer System Product Name
ProcCmdLine: BOOT_IMAGE=
ProcEnviron:
LANG=en_US.UTF-8
SHELL=/bin/bash
SourcePackage: qemu-kvm
dmi.bios.date: 08/18/2010
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1006
dmi.board.
dmi.board.name: M4A785-M
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: Rev X.0x
dmi.chassis.
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.
dmi.modalias: dmi:bvnAmerican
dmi.product.name: System Product Name
dmi.product.
dmi.sys.vendor: System manufacturer
description: | updated |
tags: | added: kvm qemu-kvm virtualization |
summary: |
- KVM SMP Linux Guests Hang + KVM SMP Linux Guests Hang on AMD |
description: | updated |
Changed in linux (Ubuntu Lucid): | |
importance: | Undecided → Medium |
status: | New → Triaged |
tags: | added: testcase |
I also want to mention that the guests are fully-updated 64-bit Ubuntu Lucid Server VMs.