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

[Kyle Mestery (kmestery)]

On Oct 22, 2012, at 9:16 AM, Laine Stump <laine at laine.org> wrote:
> On 10/22/2012 09:41 AM, Kyle Mestery (kmestery) wrote:
>> 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?
> 
> Yes. That was to be my first task this morning, but I arrived at the
> keyboard to a string of questions on IRC. I'll hopefully post something
> for you to test before noon (EST). If it works properly, and you approve
> of the changes, then I'll push.

Thanks again for the update Laine! Will test things out once you shoot the patches
out.

Thanks,
Kyle