** Description changed:

+ SRU Justification:
+ 
+ Impact: Booting an Intel based instance with certain CPU level will fail
+ with a panic as the driver does not seem to take into account that it is
+ running in a virtualized environment. This only is a problem with the
+ intel_idle driver.
+ 
+ Fix: Turning off intel_idle driver support for the virtual kernel image
+ will let it use the generic idle driver as before. As this option is
+ only changed for the virtual kernel package there is no risk of
+ regression for the generic packages.
+ 
+ Testcase: Booting a large instance (with 68GB of memory) very likely
+ results in this panic as the memory size will result in selecting
+ certain base hardware with Intel CPUs. Turning the option off lets those
+ instances boot again.
+ 
+ ---
+ 
  I saw a kernel crash in maverick RC testing.  I will attach console
  output here, the system reported is the same AMI, but the issue occurred
  on c1.xlarge instance type.
  
  The crash begins like this:
- [2725458.312511] invalid opcode: 0000 [#1] SMP 
- [2725458.312521] last sysfs file: 
- [2725458.312526] CPU 0 
+ [2725458.312511] invalid opcode: 0000 [#1] SMP
+ [2725458.312521] last sysfs file:
+ [2725458.312526] CPU 0
  [2725458.312529] Modules linked in:
- [2725458.312536] 
+ [2725458.312536]
  [2725458.312541] Pid: 0, comm: swapper Not tainted 2.6.35-22-virtual 
#33-Ubuntu /
  [2725458.312548] RIP: e030:[<ffffffff8130805c>]  [<ffffffff8130805c>] 
intel_idle+0xac/0x180
  [2725458.312565] RSP: e02b:ffffffff81a01ec8  EFLAGS: 00010046
  
  But possibly the interesting piece of data is earlier in the log:
  [    0.000000] pcpu-alloc: s91520 r8192 d23168 u122880 alloc=30*4096
- [    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 [0] 4 [0] 5 [0] 6 [0] 7 
+ [    0.000000] pcpu-alloc: [0] 0 [0] 1 [0] 2 [0] 3 [0] 4 [0] 5 [0] 6 [0] 7
  [2725457.617698] Xen: using vcpu_info placement
  [2725457.617705] Built 1 zonelists in Node order, mobility grouping on.  
Total pages: 1809808
  [2725457.617707] Policy zone: Normal
- [2725457.617711] Kernel command line: root=LABEL=uec-rootfs ro console=hvc0 
+ [2725457.617711] Kernel command line: root=LABEL=uec-rootfs ro console=hvc0
  
  There, we go from an uptime of 0.000000 to 2725457 seconds (757 hours)
  during boot.
  
  ProblemType: Bug
  DistroRelease: Ubuntu 10.10
  Package: linux-image-2.6.35-22-virtual 2.6.35-22.33
  Regression: No
  Reproducible: No
  ProcVersionSignature: User Name 2.6.35-22.33-virtual 2.6.35.4
  Uname: Linux 2.6.35-22-virtual x86_64
  AlsaDevices: Error: command ['ls', '-l', '/dev/snd/'] failed with exit code 
2: ls: cannot access /dev/snd/: No such file or directory
  AplayDevices: Error: [Errno 2] No such file or directory
  Architecture: amd64
  ArecordDevices: Error: [Errno 2] No such file or directory
  CurrentDmesg:
  
  Date: Wed Sep 29 18:03:42 2010
  Ec2AMI: ami-7a699c13
  Ec2AMIManifest: (unknown)
  Ec2AvailabilityZone: us-east-1c
  Ec2InstanceType: t1.micro
  Ec2Kernel: aki-427d952b
  Ec2Ramdisk: unavailable
  Frequency: This has only happened once.
  Lspci:
  
  Lsusb: Error: command ['lsusb'] failed with exit code 1:
  ProcCmdLine: root=LABEL=uec-rootfs ro console=hvc0
  ProcEnviron:
   PATH=(custom, user)
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  ProcModules: acpiphp 18752 0 - Live 0xffffffffa0000000
  SourcePackage: linux

** Changed in: linux (Ubuntu)
       Status: In Progress => Triaged

** Changed in: linux (Ubuntu)
     Assignee: (unassigned) => Andy Whitcroft (apw)

** Changed in: linux (Ubuntu Maverick)
     Assignee: (unassigned) => John Johansen (jjohansen)

** Changed in: linux (Ubuntu Maverick)
   Importance: Undecided => Medium

-- 
ec2 kernel crash invalid opcode 0000 [#1]
https://bugs.launchpad.net/bugs/651370
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