[ovs-dev] [PATCH] linux: Signal datapath that unaligned Netlink message can be received

[Thomas Graf]

On 11/11/2013 04:50 PM, Ben Pfaff wrote:
> On Mon, Nov 11, 2013 at 04:36:24PM +0100, Thomas Graf wrote:
>> Following commit (''netlink: Do not enforce alignment of last Netlink
>> attribute''), signal the ability to receive unaligned Netlink messages
>> to the datapath to enable utilization of zerocopy optimizations.
>>
>> Signed-off-by: Thomas Graf <tgraf at redhat.com>
>
> Seems OK from a userspace point of view.  I am a little concerned that
> downgrading userspace without deleting and re-creating the datapath
> (e.g. via "force-reload-kmod") will result in a totally broken setup
> since userspace will then drop every packet from the kernel.

Is that something that occurs occasionally in installations? Utilizing
the version field in the genl header could be used to track this and
clear user_features.