[libvirt] [PATCH 0/3] Transport Open vSwitch per-port data during live migration

Kyle Mestery (kmestery) kmestery at cisco.com
Mon Oct 22 13:41:19 UTC 2012


On Oct 11, 2012, at 4:36 PM, Kyle Mestery (kmestery) <kmestery at cisco.com> wrote:
> On Oct 11, 2012, at 4:25 PM, Laine Stump <laine at laine.org> wrote:
>> On 10/11/2012 05:06 PM, Kyle Mestery (kmestery) wrote:
>>> On Oct 1, 2012, at 10:18 AM, Kyle Mestery <kmestery at cisco.com> wrote:
>>>> This series of commits has the end goal of allowing per-port data stored
>>>> in the Open vSwitch DB to be transported during live migration. This is
>>>> done by first providing a generic infrastructure for transporting network
>>>> data, adding some utility functions specific to Open vSwitch, and hooking
>>>> the two together.
>>>> 
>>>> The framework provided is generic in that other networking data could be
>>>> transferred as well by simply adding in additional hooks as needed.
>>>> 
>>>> Kyle Mestery (3):
>>>> Add the ability for the Qemu V3 migration protocol to include    
>>>>  transporting network configuration. A generic framework is proposed
>>>>      with this patch to allow for the transfer of opaque data.
>>>> Add utility functions for Open vSwitch to both save     per-port data
>>>>  before a live migration, and restore the     per-port data after a
>>>>  live migration.
>>>> Transport Open vSwitch per-port data during live     migration by
>>>>  using the utility functions    
>>>>  virNetDevOpenvswitchGetMigrateData() and    
>>>>  virNetDevOpenvswitchSetMigrateData().
>>>> 
>>>> src/libvirt_private.syms        |   2 +
>>>> src/qemu/qemu_migration.c       | 263 +++++++++++++++++++++++++++++++++++++++-
>>>> src/util/virnetdevopenvswitch.c |  70 +++++++++++
>>>> src/util/virnetdevopenvswitch.h |   6 +
>>>> 4 files changed, 339 insertions(+), 2 deletions(-)
>>> 
>>> Just curious if anyone has had a chance to review this series yet? I believe I've addressed all the comments
>>> I've received so far. I may need to rebase and send it out again since it's been almost 2 weeks since I sent it
>>> out.
>> 
>> Sorry I haven't responded. Lately it's been one deadline after another
>> (actually I'm working on the latest as I type).
>> 
> Thanks Laine!
> 
>> One thought I've had about this - since you're just taking the data
>> directly from ovs-vsctl and printf-ing it into a buffer, there is a
>> potential that the data could contain xml meta characters (either by
>> design / on purpose, or perhaps if an attacker takes over ovs-vsctl or
>> the database in some way). This could leave the system that's the target
>> of the migration open to attacks based on injecting "something else"
>> into the migration cookie.
>> 
>> Is virBufferEscapeString() enough to both guarantee nothing like that
>> happens, as well as getting the exact same string at the destination? I
>> *think* so, but am not sure.
>> 
>> Also, I'm still not so sure about having the data as an attribute when
>> it could potentially been very long. DV, what's your opinion about this?
>> Is it okay to have very long strings as attributes, or is it considered
>> in better taste to put something that is, say, 1000 characters long as a
>> separate element?
>> 
>> Anyway, at this point I don't think you need to rebase/resend. By the
>> beginning of next week hopefully someone more wise than me about XML
>> will have answered these two questions, and I can just squash in the
>> minor changes and push it.
> 
> Thanks Laine! Let me know if you need anything else on my end.
> 
> Thanks,
> Kyle


Just pinging again on this patch set Laine. I don't think anyone responded on
your XML questions yet, so I'm unsure what the current status of this patch set
is. I assume it's in the same state?

Thanks!
Kyle




More information about the libvir-list mailing list