Bug 90381 - error when loading kvm_intel module kvm_intel unuseable
Summary: error when loading kvm_intel module kvm_intel unuseable
Status: NEW
Alias: None
Product: Virtualization
Classification: Unclassified
Component: kvm (show other bugs)
Hardware: Intel Linux
: P1 normal
Assignee: virtualization_kvm
URL:
Keywords:
Depends on:
Blocks: 94971
  Show dependency tree
 
Reported: 2014-12-27 04:55 UTC by Bhasker C V
Modified: 2015-03-17 03:53 UTC (History)
2 users (show)

See Also:
Kernel Version: 3.18.1
Subsystem:
Regression: No
Bisected commit-id:


Attachments
kernel crash message (3.58 KB, text/plain)
2014-12-27 04:55 UTC, Bhasker C V
Details

Description Bhasker C V 2014-12-27 04:55:35 UTC
Created attachment 161951 [details]
kernel crash message

Hi,
 Whenever I load the kvm_intel module (on my machine which does support vmx), the kernel crashes  (not a catastropic crash but the module is no longer useable). kvm_intel is unuseable.
Comment 1 Bhasker C V 2014-12-27 04:56:58 UTC
The machine (also can be found in the crash attachment) is 

Dell D620 with processor features as below: 

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 15
model name	: Intel(R) Core(TM)2 CPU         T5500  @ 1.66GHz
stepping	: 2
microcode	: 0x5c
cpu MHz		: 1000.000
cache size	: 2048 KB
physical id	: 0
siblings	: 2
core id		: 1
cpu cores	: 2
apicid		: 1
initial apicid	: 1
fpu		: yes
fpu_exception	: yes
cpuid level	: 10
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good nopl aperfmperf pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm dtherm tpr_shadow
bugs		:
bogomips	: 3328.70
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:
Comment 2 Bhasker C V 2014-12-27 05:02:57 UTC
The 3.14.x stock kernel (of debian)  works fine but 3.17.x also does the same crash. I do nott have any other kernel revisions inbetween to iterate.
Comment 3 Bhasker C V 2014-12-27 05:19:39 UTC
Managed to load the kvm_intel without a crash. This crash seems to happen _only_ if nested=1 is given in the options.
Comment 4 Kashyap Chamarthy 2014-12-27 10:25:30 UTC
Can't reproduce this with Kernel 3.18.1 (current upstream stable) -- tested nested virtualization with KVM. If you face issues with Debian specific Kernels, you might want to report it with Debian Kernel bug tracker.

Since this is upstream tracker, you might have to reproduce this with 3.18  (or with 3.19-rc1 mainline).
Comment 5 Bhasker C V 2014-12-28 00:47:19 UTC
I am using 3.18.1 on my other DELL Q15R and this crash is not happening. 
This crash is particularly happening on the DELL D620 core2duo machines only.
kvm (as per my comment above) does work fine but crashes _only_ when loaded as
modprobe kvm_intel nested=1

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