[Qemu-devel] Re: Live migration of x86-64 kvm guests broken?

[Jan Kiszka]

Ryan Harper wrote:
> * Jan Kiszka <address@hidden> [2009-12-02 12:07]:
>> Ryan Harper wrote:
>>> * Jan Kiszka <address@hidden> [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

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