Xen users - Oct 2008 - Error: Migration not permitted with assigned PCI device

Hi everyone!

I''m getting the above error while trying to live-migrate a VM that
needs
to use /dev/ttyS0 and /dev/ttyS1..
I''m confused though: does it mean that I _can''t_ do live
migration of a
VM that uses a PCI device (additional serial device in my case) or 
simply that something is wrong with my config?

Dom0 and DomU using CentOS 5.2, Xen 3.2.1, kernel 2.6.18

vm.cfg :

 > name        = ''fax''
 > kernel      = ''/boot/vmlinuz-2.6.18-92.1.10.el5xen''
 > ramdisk     = ''/boot/initrd-guest-2.6.18-92.1.10.el5xen''
 > memory      = ''576''
 > root        = ''/dev/xvda1 ro''
 > disk        = [
 >                   ''drbd:fax-disk,xvda1,w'',
 >                   ''drbd:fax-swap,xvda2,w'',
 >               ]
 > vif         = [ ''ip=192.168.1.213,mac=00:16:3E:CC:AB:6D''
]
 > on_poweroff = ''destroy''
 > on_reboot   = ''restart''
 > on_crash    = ''preserve''
 >
 > # ttyS0
 > irq = [ 4 ]
 > ioports = [ "3f8-3ff" ]
 > # ttyS1
 > pci = [ ''01:07.0'' ]


Script to enable PCI passthrough:

 > #!/bin/bash
 > pci1=0000:01:07.0
 > driver1=serial
 >
 > modprobe pciback
 >
 > # hide the device from dom0 so pciback can take control
 > echo -n $pci1 >  /sys/bus/pci/drivers/$driver1/unbind
 > sleep 1
 > # Give the device to pciback, give it a new slot then bind
 > echo -n $pci1 >  /sys/bus/pci/drivers/pciback/new_slot
 > sleep 1
 > echo -n $pci1 >  /sys/bus/pci/drivers/pciback/bind


Command output:
> [root@server1 ~]# xm migrate fax server2x --live
> Error: Migration not permitted with assigned PCI device.
> Usage: xm migrate <Domain> <Host>

Thanks for your time!


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

On Thu, Oct 23, 2008 at 2:34 AM, Federico Fanton <fake@panizzolo.it>
wrote:
> I''m confused though: does it mean that I _can''t_ do live
migration of a VM
> that uses a PCI device (additional serial device in my case) or simply that
exactly


-- 
Javier

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Javier Guerra wrote:
> On Thu, Oct 23, 2008 at 2:34 AM, Federico Fanton <fake@panizzolo.it>
wrote:
>> I''m confused though: does it mean that I _can''t_ do
live migration of a VM
>> that uses a PCI device (additional serial device in my case) or simply
that
> 
> exactly
I see :(
Do you know if this is a planned feature, maybe?


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

How do you expect to do live migration of a machine that has a PCI
device assigned?  What if you migrate to another server that does not
have that PCI device, or has it, but at a different bus location?  This
could cause major problems in the machine after migration.  Xen doesn''t
know (and doesn''t care) what type of PCI device you''re passing
through,
so what if it''s a storage controller?  If you''re allowed to
migrate a
machine with PCI devices assigned, and you migrate one that has a
storage controller assigned, the machine is going to crash.

Sorry, I missed the beginning of this thread, but what type of device
are you passing through?

-Nick

On Wed, 2008-10-29 at 16:34 +0100, Federico Fanton
wrote:
> Javier Guerra wrote:
> > On Thu, Oct 23, 2008 at 2:34 AM, Federico Fanton
<fake@panizzolo.it> wrote:
> >> I''m confused though: does it mean that I _can''t_
do live migration of a VM
> >> that uses a PCI device (additional serial device in my case) or
simply that
> > 
> > exactly
> 
> I see :(
> Do you know if this is a planned feature, maybe?
> 
> 



This e-mail may contain confidential and privileged material for the sole use of
the intended recipient.  If this email is not intended for you, or you are not
responsible for the delivery of this message to the intended recipient, please
note that this message may contain SEAKR Engineering (SEAKR)
Privileged/Proprietary Information.  In such a case, you are strictly prohibited
from downloading, photocopying, distributing or otherwise using this message,
its contents or attachments in any way.  If you have received this message in
error, please notify us immediately by replying to this e-mail and delete the
message from your mailbox.  Information contained in this message that does not
relate to the business of SEAKR is neither endorsed by nor attributable to
SEAKR.

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

> I see :(
> Do you know if this is a planned feature, maybe?
>
Looks like the developers have already been working on it:

http://www.xen.org/files/xensummitboston08/NetworkingViaDirectFunctionAssignment.pdf

see also:
http://www.xen.org/xensummit/xensummit_summer_2008.html
(under the section "Next Generation I/O"

Cheers,
Todd

-- 
Todd Deshane
http://todddeshane.net
http://runningxen.com

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Nick Couchman wrote:
> How do you expect to do live migration of a machine that has a PCI
> device assigned?  What if you migrate to another server that does not
> have that PCI device, or has it, but at a different bus location?  This
> could cause major problems in the machine after migration.  Xen
doesn''t
> know (and doesn''t care) what type of PCI device you''re
passing through,
> so what if it''s a storage controller?  If you''re allowed
to migrate a
> machine with PCI devices assigned, and you migrate one that has a
> storage controller assigned, the machine is going to crash.
Well, I understand that it is a complex task, but maybe there could be a 
list of "migrable PCI devices" that wouldn''t give problems to
Xen.. And
of course it would work only with ad-hoc configured machines.. I wasn''t
getting into the details, I was just asking :)
> Sorry, I missed the beginning of this thread, but what type of device
> are you passing through?
A serial port.

Bye!


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

Todd Deshane wrote:
>> Do you know if this is a planned feature, maybe?
> 
> Looks like the developers have already been working on it:
> 
>
http://www.xen.org/files/xensummitboston08/NetworkingViaDirectFunctionAssignment.pdf
> 
> see also:
> http://www.xen.org/xensummit/xensummit_summer_2008.html
> (under the section "Next Generation I/O"
I see, thanks :)


_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users

> Well, I understand that it is a complex task, but maybe there could be a
> list of "migrable PCI devices" that wouldn''t give
problems to Xen.. And of
> course it would work only with ad-hoc configured machines.. I
wasn''t getting
> into the details, I was just asking :)
see: http://www.nabble.com/-PATCH---VTD--Update-vtd.txt-td18847433.html

''From changeset: 18047:39c2cab9e765 on, there is a shell utility 
"xm
pci-list-assignable-devices"''

Cheers,
Todd

-- 
Todd Deshane
http://todddeshane.net
http://runningxen.com

_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users