Re: KVM-AMD OOPS

[Avi Kivity <avi@argo.co.il>]

Jeremy Fitzhardinge wrote:
> Sasa Ostrouska wrote:
>> root@rcserver:~# modprobe kvm-amd
>> int3: 0000 [1] PREEMPT SMP
>> CPU 1
>> Modules linked in: kvm_amd snd_seq_dummy snd_seq_oss
>> snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss
>> nls_iso8859_1 ntfs nls_base usb_storage libusual capability commoncap
>> lp psmouse snd_hda_intel snd_hda_codec snd_pcm snd_timer ohci_hcd
>> ehci_hcd 8139too rtc_cmos snd soundcore snd_page_alloc usbcore k8temp
>> mii rtc_core rtc_lib i2c_nforce2 parport_pc parport
>> Pid: 2898, comm: modprobe Tainted: P       2.6.21.5 #1
>> RIP: 0010:[<ffffffff80572364>]  [<ffffffff80572364>]
>> register_cpu_notifier+0x1/0x31
>> RSP: 0000:ffff81006e34df40  EFLAGS: 00000246
>> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000c0010117
>> RDX: 000000000000ffff RSI: ffff81006e219640 RDI: ffffffff80536510
>> RBP: ffffffff880d8840 R08: 0000000000000000 R09: 000000000006b5f4
>> R10: 0000000000000000 R11: 0000000000000000 R12: 00000000005296b0
>> R13: 00007fff51fe55c0 R14: 0000000000000000 R15: 0000000000000000
>> FS:  00002b4e58e18b00(0000) GS:ffff810002e794c0(0000)
>> knlGS:0000000000000000
>> CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
>> CR2: 000000000050df64 CR3: 000000007a0f3000 CR4: 00000000000006e0
>> Process modprobe (pid: 2898, threadinfo ffff81006e34c000, task
>> ffff81007bc48400)
>> Stack:  ffffffff8039e024 ffff81006e34c000 ffffffff880d8840
>> 0000000000005e19
>> ffffffff8024537c 0000000000000000 00007fff51fe50c0 00000000004142d0
>> ffffffff8020967e 0000000000000206 00000000005230e0 000000000052f4c9
>> Call Trace:
>> [<ffffffff8039e024>] kvm_init_arch+0x90/0x145
>> [<ffffffff8024537c>] sys_init_module+0xad/0x168
>> [<ffffffff8020967e>] system_call+0x7e/0x83
>>
>>
>> Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc
>
> This is the init section poison pattern.  Looks like an init function
> was used after the code was freed.

Indeed, the function is register_cpu_notifier which is declared
__cpuinit, which, without hotplug compiled in, is simply __init.

I'll prepare a patch for this.  Meanwhile, you can work around it by
enabling CONFIG_HOTPLUG_CPU.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.