Re: Live migration of x86-64 kvm guests broken?

Jan Kiszka
2009-12-02T18:17:06Z

Ryan Harper wrote:
> * Jan Kiszka <jan.kiszka@siemens.com> [2009-12-02 12:07]:
>> Ryan Harper wrote:
>>> * Jan Kiszka <jan.kiszka@siemens.com> [2009-12-02 09:28]:
>>>> Hi,
>>>>
>>>> I'm facing stalled x86-64 guests after live migration when using kvm
>>>> (share disk images). This does not happen with x86-32 guests or when
>>>> disabling kvm. Both qemu and qemu-kvm git heads are affected (recent
>>>> vmstate fixes applied). Running I/O load during the migration (e.g. a
>>>> simple "ls -R /") seems to trigger it reliably.
>>>>
>>>> Can anyone confirm / comment on this? Do we fail to restore some magic
>>>> state that only long mode cares about?
>>> Just tested upstream qemu.git (with vmstate fixes) and I could migrate
>>> RHEL 5.3 64-bit guest with your light io load over localhost. I'll try
>>> remote hosts next.
>> Hell, too many variables. It looks like the kernel modules have some if
>> not the ultimate impact: kvm-mod-2.6.31.6b on my 2.6.27 host works fine,
>> kvm-kmod stable-2.6.32 as well as master cause troubles.
>>
>> What is your host kernel and/or kvm module version?
>
> Stock 64-bit Ubuntu Karmic:
> % uname -a
> Linux symmetry 2.6.31-15-generic #50-Ubuntu SMP Tue Nov 10 14:53:52 UTC 2009 x86_64 GNU/Linux
>
> % modinfo kvm
> filename:
> /lib/modules/2.6.31-15-generic/kernel/arch/x86/kvm/kvm.ko
> license: GPL
> author: Qumranet
> srcversion: 82D6B673524596F9CF3E84C
> depends:
> vermagic: 2.6.31-15-generic SMP mod_unload modversions
> parm: oos_shadow:bool
>
> % modinfo kvm-intel
> filename: /lib/modules/2.6.31-15-generic/kernel/arch/x86/kvm/kvm-intel.ko
> license: GPL
> author: Qumranet
> srcversion: 8FEA479DFCD7F174DA7864E
> depends: kvm
> vermagic: 2.6.31-15-generic SMP mod_unload modversions
> parm: bypass_guest_pf:bool
> parm: vpid:bool
> parm: flexpriority:bool
> parm: ept:bool
> parm: emulate_invalid_guest_state:bool
>

So far, so consistent. Could you try kvm-kmod-2.6.32-rc7 on top of that?

Jan

--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux