Re: [Qemu-discuss] Live migration of VM

[Prashant Upadhyaya]

Hi,

Case A and B are what I am looking for.
I believe B is more likely for practical usecases for speed of guest execution.

I saw this news from 2008 and thought that years have passed, so this must be 
possible now. But looks like this still hasn't matured.

http://beta.slashdot.org/story/109745

Would love to hear comments on the above story from back then.

Regards
-Prashant


-----Original Message-----
From: address@hidden [mailto:address@hidden On Behalf Of Jakob Bohm
Sent: Wednesday, May 28, 2014 11:02 PM
To: address@hidden
Subject: Re: [Qemu-discuss] Live migration of VM

On 5/23/2014 8:19 AM, Prashant Upadhyaya wrote:
> Hi,
>
> Is it possible to  live migrate a VM (emulating AMD) running on native
> AMD to a machine running native ARM and back with QEMU ?
>
>

I believe a clarification is needed here.

What is it you want to do:

   A) Migrate the VM from qemu-system-x86_64 software emulating an
     AMD64 guest on an AMD64 host to qemu-system-x86_64 software
     emulating the same AMD64 guest on an ARM host.

   B) Migrate the VM from qemu-system-x86_64 KVM emulating an
     AMD64 guest on an AMD64 host to qemu-system-x86_64 software
     emulating the same AMD64 guest on an ARM host

   C) Migrate the VM from qemu-system-x86_64 emulating an
     AMD64 guest on an AMD64 host to qemu-system-arm emulating
     an ARM guest on an ARM host.

C) Is mostly impossible, because the Guest memory needs to contain
   completely different code when the virtual machine suddenly
   swaps its (virtual) CPU from AMD64 to ARM.

A) Might be possible, unless there is some oddity in the qemu code
   which transmits the virtual machine state differently depending
   on the Host architecture.

B) Might be more difficult, if the qemu code transmits KVM virtual
   machine state differently from equivalent software emulated
   virtual machine state.



Enjoy

Jakob
--
Jakob Bohm, CIO, Partner, WiseMo A/S.  http://www.wisemo.com Transformervej 29, 
2730 Herlev, Denmark.  Direct +45 31 13 16 10 This public discussion message is 
non-binding and may contain errors.
WiseMo - Remote Service Management for PCs, Phones and Embedded



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