[Qemu-devel] Qemu live migration code

[Qemu-devel] Qemu live migration code

[Bechir Bani]

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Hi,

I want to know the source code of qemu which is responsible for the
migration of virtual machines, more precisely where the part of the code
that describes the stages of memory transfer. is that you can help me?


Thank you !




-- 
*Béchir Bani *
****************************************************************
*Ecole Polytechnique de Montréal *
****************************************************************
*Laboratoire DORSAL*
*****************************************************************
*Montréal - Canada*

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Re: [Qemu-devel] Qemu live migration code

[陈梁]

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Hi, the function of migration_thread maybe is your want. 

Best regards.

> Hi,
> 
> I want to know the source code of qemu which is responsible for the migration of virtual machines, more precisely where the part of the code that describes the stages of memory transfer. is that you can help me?
> 
> 
> Thank you !
> 
> 
> 
> 
> -- 
> Béchir Bani 
> **************************************************************
> Ecole Polytechnique de Montréal 
> **************************************************************
> Laboratoire DORSAL
> ***************************************************************
> Montréal - Canada


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Re: [Qemu-devel] Qemu live migration code

[Dr. David Alan Gilbert]

* Bechir Bani (bechir.bani@gmail.com) wrote:
> Hi,
> 
> I want to know the source code of qemu which is responsible for the
> migration of virtual machines, more precisely where the part of the code
> that describes the stages of memory transfer. is that you can help me?

It's split around a few files; memory is mostly in arch_init.c;
It's something like:

   migration.c       Overall management
      savevm.c        
        qemu-file.c    File buffering/bytes on the wire
        vmstate.c      Structured saving of individual devices
        arch_init.c    RAM special code, and a few other things

What are you trying to do/change?

Dave

--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] Qemu live migration code

[Bechir Bani]

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I have a task to add trace points in the source code of Qemu. The goal is
to know the number of pages transferred at each iteration and stop time of
the machine as well.


2014-03-24 12:50 GMT-04:00 Dr. David Alan Gilbert <dgilbert@redhat.com>:

> * Bechir Bani (bechir.bani@gmail.com) wrote:
> > Hi,
> >
> > I want to know the source code of qemu which is responsible for the
> > migration of virtual machines, more precisely where the part of the code
> > that describes the stages of memory transfer. is that you can help me?
>
> It's split around a few files; memory is mostly in arch_init.c;
> It's something like:
>
>    migration.c       Overall management
>       savevm.c
>         qemu-file.c    File buffering/bytes on the wire
>         vmstate.c      Structured saving of individual devices
>         arch_init.c    RAM special code, and a few other things
>
> What are you trying to do/change?
>
> Dave
>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>



-- 
*Béchir Bani *
****************************************************************
*Ecole Polytechnique de Montréal *
****************************************************************
*Laboratoire DORSAL*
*****************************************************************
*Montréal - Canada*

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Re: [Qemu-devel] Qemu live migration code

[Sanidhya Kashyap]

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savevm.c will tell you about the stop time.

arch_init.c (ram_save_block) will tell about the number of pages
transferred.


On Mon, Mar 24, 2014 at 10:51 PM, Bechir Bani <bechir.bani@gmail.com> wrote:

> I have a task to add trace points in the source code of Qemu. The goal is
> to know the number of pages transferred at each iteration and stop time of
> the machine as well.
>
>
> 2014-03-24 12:50 GMT-04:00 Dr. David Alan Gilbert <dgilbert@redhat.com>:
>
> * Bechir Bani (bechir.bani@gmail.com) wrote:
>> > Hi,
>> >
>> > I want to know the source code of qemu which is responsible for the
>> > migration of virtual machines, more precisely where the part of the code
>> > that describes the stages of memory transfer. is that you can help me?
>>
>> It's split around a few files; memory is mostly in arch_init.c;
>> It's something like:
>>
>>    migration.c       Overall management
>>       savevm.c
>>         qemu-file.c    File buffering/bytes on the wire
>>         vmstate.c      Structured saving of individual devices
>>         arch_init.c    RAM special code, and a few other things
>>
>> What are you trying to do/change?
>>
>> Dave
>>
>> --
>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>>
>
>
>
> --
> *Béchir Bani *
> ****************************************************************
> *Ecole Polytechnique de Montréal *
> ****************************************************************
> *Laboratoire DORSAL*
> *****************************************************************
> *Montréal - Canada*
>

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Re: [Qemu-devel] Qemu live migration code

[Bechir Bani]

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Hi Sanidhya,


Which function in savevm.c can tell me about the stop time ?


2014-03-24 13:46 GMT-04:00 Sanidhya Kashyap <sanidhya.iiith@gmail.com>:

> savevm.c will tell you about the stop time.
>
> arch_init.c (ram_save_block) will tell about the number of pages
> transferred.
>
>
> On Mon, Mar 24, 2014 at 10:51 PM, Bechir Bani <bechir.bani@gmail.com>wrote:
>
>> I have a task to add trace points in the source code of Qemu. The goal is
>> to know the number of pages transferred at each iteration and stop time of
>> the machine as well.
>>
>>
>> 2014-03-24 12:50 GMT-04:00 Dr. David Alan Gilbert <dgilbert@redhat.com>:
>>
>> * Bechir Bani (bechir.bani@gmail.com) wrote:
>>> > Hi,
>>> >
>>> > I want to know the source code of qemu which is responsible for the
>>> > migration of virtual machines, more precisely where the part of the
>>> code
>>> > that describes the stages of memory transfer. is that you can help me?
>>>
>>> It's split around a few files; memory is mostly in arch_init.c;
>>> It's something like:
>>>
>>>    migration.c       Overall management
>>>       savevm.c
>>>         qemu-file.c    File buffering/bytes on the wire
>>>         vmstate.c      Structured saving of individual devices
>>>         arch_init.c    RAM special code, and a few other things
>>>
>>> What are you trying to do/change?
>>>
>>> Dave
>>>
>>> --
>>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>>>
>>
>>
>>
>> --
>> *Béchir Bani *
>> ****************************************************************
>> *Ecole Polytechnique de Montréal *
>> ****************************************************************
>> *Laboratoire DORSAL*
>> *****************************************************************
>> *Montréal - Canada*
>>
>
>


-- 
*Béchir Bani *
****************************************************************
*Ecole Polytechnique de Montréal *
****************************************************************
*Laboratoire DORSAL*
*****************************************************************
*Montréal - Canada*

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Re: [Qemu-devel] Qemu live migration code

[Sanidhya Kashyap]

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On Tue, Mar 25, 2014 at 2:10 AM, Bechir Bani <bechir.bani@gmail.com> wrote:

> Hi Sanidhya,
>
>
> Which function in savevm.c can tell me about the stop time ?
>
>
the migration thread function in migration.c file which has function name -
qemu_savevm_state_complete will get executed in the stop and copy phase.


>
> 2014-03-24 13:46 GMT-04:00 Sanidhya Kashyap <sanidhya.iiith@gmail.com>:
>
> savevm.c will tell you about the stop time.
>>
>> arch_init.c (ram_save_block) will tell about the number of pages
>> transferred.
>>
>>
>> On Mon, Mar 24, 2014 at 10:51 PM, Bechir Bani <bechir.bani@gmail.com>wrote:
>>
>>> I have a task to add trace points in the source code of Qemu. The goal
>>> is to know the number of pages transferred at each iteration and stop time
>>> of the machine as well.
>>>
>>>
>>> 2014-03-24 12:50 GMT-04:00 Dr. David Alan Gilbert <dgilbert@redhat.com>:
>>>
>>> * Bechir Bani (bechir.bani@gmail.com) wrote:
>>>> > Hi,
>>>> >
>>>> > I want to know the source code of qemu which is responsible for the
>>>> > migration of virtual machines, more precisely where the part of the
>>>> code
>>>> > that describes the stages of memory transfer. is that you can help me?
>>>>
>>>> It's split around a few files; memory is mostly in arch_init.c;
>>>> It's something like:
>>>>
>>>>    migration.c       Overall management
>>>>       savevm.c
>>>>         qemu-file.c    File buffering/bytes on the wire
>>>>         vmstate.c      Structured saving of individual devices
>>>>         arch_init.c    RAM special code, and a few other things
>>>>
>>>> What are you trying to do/change?
>>>>
>>>> Dave
>>>>
>>>> --
>>>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>>>>
>>>
>>>
>>>
>>> --
>>> *Béchir Bani *
>>> ****************************************************************
>>> *Ecole Polytechnique de Montréal *
>>> ****************************************************************
>>> *Laboratoire DORSAL*
>>> *****************************************************************
>>> *Montréal - Canada*
>>>
>>
>>
>
>
> --
> *Béchir Bani *
> ****************************************************************
> *Ecole Polytechnique de Montréal *
> ****************************************************************
> *Laboratoire DORSAL*
> *****************************************************************
> *Montréal - Canada*
>

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Re: [Qemu-devel] Qemu live migration code

[Bechir Bani]

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 Hi ,

There is someone who can explain to me the role of two trace points in the
file* Migration.c *

The trace points are :

 *  migrate_pending* : what are the attributes *pending size *and *max* ?

 *  migrate_transferred*: what are the attributes *transferred* ,*
time_spent* , *bandwidth* and *max_size* ?


Thank you !


2014-03-25 6:03 GMT-04:00 Sanidhya Kashyap <sanidhya.iiith@gmail.com>:

>
>
>
> On Tue, Mar 25, 2014 at 2:10 AM, Bechir Bani <bechir.bani@gmail.com>wrote:
>
>> Hi Sanidhya,
>>
>>
>> Which function in savevm.c can tell me about the stop time ?
>>
>>
> the migration thread function in migration.c file which has function name
> - qemu_savevm_state_complete will get executed in the stop and copy phase.
>
>
>>
>> 2014-03-24 13:46 GMT-04:00 Sanidhya Kashyap <sanidhya.iiith@gmail.com>:
>>
>> savevm.c will tell you about the stop time.
>>>
>>> arch_init.c (ram_save_block) will tell about the number of pages
>>> transferred.
>>>
>>>
>>> On Mon, Mar 24, 2014 at 10:51 PM, Bechir Bani <bechir.bani@gmail.com>wrote:
>>>
>>>> I have a task to add trace points in the source code of Qemu. The goal
>>>> is to know the number of pages transferred at each iteration and stop time
>>>> of the machine as well.
>>>>
>>>>
>>>> 2014-03-24 12:50 GMT-04:00 Dr. David Alan Gilbert <dgilbert@redhat.com>
>>>> :
>>>>
>>>> * Bechir Bani (bechir.bani@gmail.com) wrote:
>>>>> > Hi,
>>>>> >
>>>>> > I want to know the source code of qemu which is responsible for the
>>>>> > migration of virtual machines, more precisely where the part of the
>>>>> code
>>>>> > that describes the stages of memory transfer. is that you can help
>>>>> me?
>>>>>
>>>>> It's split around a few files; memory is mostly in arch_init.c;
>>>>> It's something like:
>>>>>
>>>>>    migration.c       Overall management
>>>>>       savevm.c
>>>>>         qemu-file.c    File buffering/bytes on the wire
>>>>>         vmstate.c      Structured saving of individual devices
>>>>>         arch_init.c    RAM special code, and a few other things
>>>>>
>>>>> What are you trying to do/change?
>>>>>
>>>>> Dave
>>>>>
>>>>> --
>>>>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> *Béchir Bani *
>>>> ****************************************************************
>>>> *Ecole Polytechnique de Montréal *
>>>> ****************************************************************
>>>> *Laboratoire DORSAL*
>>>> *****************************************************************
>>>> *Montréal - Canada*
>>>>
>>>
>>>
>>
>>
>> --
>> *Béchir Bani *
>> ****************************************************************
>> *Ecole Polytechnique de Montréal *
>> ****************************************************************
>> *Laboratoire DORSAL*
>> *****************************************************************
>> *Montréal - Canada*
>>
>
>


-- 
*Béchir Bani *
****************************************************************
*Ecole Polytechnique de Montréal *
****************************************************************
*Laboratoire DORSAL*
*****************************************************************
*Montréal - Canada*

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Re: [Qemu-devel] Qemu live migration code

[Dr. David Alan Gilbert]

* Bechir Bani (bechir.bani@gmail.com) wrote:
>  Hi ,
> 
> There is someone who can explain to me the role of two trace points in the
> file* Migration.c *
> 
> The trace points are :
> 
>  *  migrate_pending* : what are the attributes *pending size *and *max* ?

'pending_size' is an estimate of the amount of data left to be transferred
in the iterative part.
'max_size' is an estimate of the amount of data that can be transferred in the
'max_downtime' period
Thus if pending_size < max_size it can stop iterating and transfer the last
part.

>  *  migrate_transferred*: what are the attributes *transferred* ,*
> time_spent* , *bandwidth* and *max_size* ?

Every so often it recalculates bandwidths etc:
   transferred_bytes - actual bytes transferred during migration since the last
              time it did that set of calculations
   time_spent - time since it last did that set of calculations
   bandwidth - transferred_bytes  / time_spent
   max_size = as in the previous trace point.

Dave
   
> 
> 
> Thank you !
> 
> 
> 2014-03-25 6:03 GMT-04:00 Sanidhya Kashyap <sanidhya.iiith@gmail.com>:
> 
> >
> >
> >
> > On Tue, Mar 25, 2014 at 2:10 AM, Bechir Bani <bechir.bani@gmail.com>wrote:
> >
> >> Hi Sanidhya,
> >>
> >>
> >> Which function in savevm.c can tell me about the stop time ?
> >>
> >>
> > the migration thread function in migration.c file which has function name
> > - qemu_savevm_state_complete will get executed in the stop and copy phase.
> >
> >
> >>
> >> 2014-03-24 13:46 GMT-04:00 Sanidhya Kashyap <sanidhya.iiith@gmail.com>:
> >>
> >> savevm.c will tell you about the stop time.
> >>>
> >>> arch_init.c (ram_save_block) will tell about the number of pages
> >>> transferred.
> >>>
> >>>
> >>> On Mon, Mar 24, 2014 at 10:51 PM, Bechir Bani <bechir.bani@gmail.com>wrote:
> >>>
> >>>> I have a task to add trace points in the source code of Qemu. The goal
> >>>> is to know the number of pages transferred at each iteration and stop time
> >>>> of the machine as well.
> >>>>
> >>>>
> >>>> 2014-03-24 12:50 GMT-04:00 Dr. David Alan Gilbert <dgilbert@redhat.com>
> >>>> :
> >>>>
> >>>> * Bechir Bani (bechir.bani@gmail.com) wrote:
> >>>>> > Hi,
> >>>>> >
> >>>>> > I want to know the source code of qemu which is responsible for the
> >>>>> > migration of virtual machines, more precisely where the part of the
> >>>>> code
> >>>>> > that describes the stages of memory transfer. is that you can help
> >>>>> me?
> >>>>>
> >>>>> It's split around a few files; memory is mostly in arch_init.c;
> >>>>> It's something like:
> >>>>>
> >>>>>    migration.c       Overall management
> >>>>>       savevm.c
> >>>>>         qemu-file.c    File buffering/bytes on the wire
> >>>>>         vmstate.c      Structured saving of individual devices
> >>>>>         arch_init.c    RAM special code, and a few other things
> >>>>>
> >>>>> What are you trying to do/change?
> >>>>>
> >>>>> Dave
> >>>>>
> >>>>> --
> >>>>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
> >>>>>
> >>>>
> >>>>
> >>>>
> >>>> --
> >>>> *Béchir Bani *
> >>>> ****************************************************************
> >>>> *Ecole Polytechnique de Montréal *
> >>>> ****************************************************************
> >>>> *Laboratoire DORSAL*
> >>>> *****************************************************************
> >>>> *Montréal - Canada*
> >>>>
> >>>
> >>>
> >>
> >>
> >> --
> >> *Béchir Bani *
> >> ****************************************************************
> >> *Ecole Polytechnique de Montréal *
> >> ****************************************************************
> >> *Laboratoire DORSAL*
> >> *****************************************************************
> >> *Montréal - Canada*
> >>
> >
> >
> 
> 
> -- 
> *Béchir Bani *
> ****************************************************************
> *Ecole Polytechnique de Montréal *
> ****************************************************************
> *Laboratoire DORSAL*
> *****************************************************************
> *Montréal - Canada*
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK