Bugzilla Bug 1585

Environment:
------------
Service Arch (ia32/ia32e/IA64): ia32/ia32e
Guest Arch (ia32/ia32e/IA64): 
Guest OS Type (Linux/Windows):
Change Set: 20990
Hardware: Stoakley
Other:
xen-changeset:   20990:46bfb4a318e9

pvops git:
commit 0a61300806b741e5e7a5f96f36e4317fc0329737
Merge: 543318f... 7937752...
Author: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

ioemu git:
commit f3f98c2c705fbb773e88692e016d828a060793c8
Author: Ian Jackson <ian.jackson@eu.citrix.com>
Date:   Mon Mar 1 16:14:50 2010 +0000


Bug detailed description:
--------------------------
On Stoakley, set cpufreq governor to ondeman explicitly will cause Xen crash.
The issue is only found on Stoakley. Westmere-HEDT has no such issue.

##########
(XEN) ----[ Xen-4.0.0-rc6-pre  x86_32p  debug=y  Not tainted ]----
(XEN) CPU:    0
(XEN) EIP:    e008:[<ff130a22>] cpufreq_governor_dbs+0x2f8/0x357
(XEN) EFLAGS: 00010246   CONTEXT: hypervisor
(XEN) eax: 00000000   ebx: ffb7ce30   ecx: 00000003   edx: 002ab980
(XEN) esi: ff233200   edi: 00000000   ebp: ff2b7dac   esp: ff2b7d74
(XEN) cr0: 8005003b   cr4: 000026f0   cr3: 00b36c80   cr2: 00000028
(XEN) ds: e010   es: e010   fs: 00d8   gs: 0033   ss: e010   cs: e008
(XEN) Xen stack trace from esp=ff2b7d74:
(XEN)    ff2b7e24 ffb7ce88 ff2b7e24 00211841 24000001 00000000 002ab980
00000000
(XEN)    00000040 00000000 ff2b7e0c ff2b7e24 ffb7ce30 ff20d680 ff2b7dcc
ff131657
(XEN)    ffb7ce30 00000003 00000010 ffb7ce30 ffb7ce64 ff2b7e58 ff2b7e6c
ff13e6e6
(XEN)    ffb7ce30 ff2b7e24 ff2b7e0c ff112253 00000005 ff2b7ec8 00000000
ff2b7e24
(XEN)    ffb36000 ffb50000 124a0025 00000002 ff168b9a 092be000 ff2b7ef4
00000000
(XEN)    00000000 00000001 ff2b7f0c ff1584da 00000001 00000000 00000002
00000000
(XEN)    002ab980 00249f00 00249f00 00002710 00249f00 002ab980 002ab980
ff20d680
(XEN)    00000001 00000246 ff20d228 092be000 092be000 fffffff3 ff2b7f8c
ff11cbd3
(XEN)    ff2b7efc 092be000 00000088 00000000 00000002 c0251d9c 00000002
00000004
(XEN)    00000001 00000000 00000001 ffb36000 ffb50000 ffb50000 ff2b7eec
ff151f66
(XEN)    f6d43798 ff2b7ef8 f57b3000 c0251d98 ed5ff90c 00000000 c5fef900
ea4a3ec0
(XEN)    c16aa460 000e0003 c10207c4 00000061 00000292 ea4a3eac 00000069
0000007b
(XEN)    0000000c 00000007 00000012 00000000 65646e6f 646e616d 00000000
00000000
(XEN)    00000000 00000000 00cce170 092bd010 00000002 00000007 00000001
00000004
(XEN)    00000008 00000000 002aba18 00000000 00cccff4 00cce140 bfdddc0e
bfddce88
(XEN)    00bf83ab 00cce140 00000009 00cccff4 00000009 bfdddc0e bfddcea8
00bfc6f6
(XEN)    092bd018 bfdddc0e aaaaaaaa ffb36000 00000023 ff2b7fac 00d48037
ff1d1c68
(XEN)    092be000 deadbeef deadbeef deadbeef deadbeef deadbeef c1002467
00000023
(XEN)    092be000 00bf801b 00bf6271 bfddcde8 bfddce40 ea4a3f18 00000023
000e0003
(XEN)    c1002467 00000061 00000286 ea4a3ea8 00000069 0000007b 0000007b
000000d8
(XEN) Xen call trace:
(XEN)    [<ff130a22>] cpufreq_governor_dbs+0x2f8/0x357
(XEN)    [<ff131657>] __cpufreq_set_policy+0xe2/0xf6
(XEN)    [<ff13e6e6>] do_pm_op+0x5d3/0x9ad
(XEN)    [<ff11cbd3>] do_sysctl+0x653/0x8d0
(XEN)    [<ff1d1c68>] hypercall+0xb8/0xd8
(XEN)
(XEN) Pagetable walk from 00000028:
(XEN)  L3[0x000] = 000000002c899001 0002804f
(XEN)  L2[0x000] = 0000000000000000 ffffffff
(XEN)
(XEN) ****************************************
(XEN) Panic on CPU 0:
(XEN) FATAL PAGE FAULT
(XEN) [error_code=0000]
(XEN) Faulting linear address: 00000028
(XEN) ****************************************
(XEN)
(XEN) Reboot in five seconds...
##########

Verified with following c/s, the bug is fixed:

xen-changeset:   21022:132ac04cbdba

pvops git: 
commit eb739cf358e03cd6ab69437d2429bcc8ad57d45b
Merge: be6c421... 5e20b95...
Author: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

ioemu git: 
commit 4ee8bdd513b4d7af0e14434f4c53887779a33eda
Author: Ian Jackson <ian.jackson@eu.citrix.com>
Date:   Tue Mar 9 17:55:41 2010 +0000