Re: [PATCH V2 09/12] net/eipoib: Add main driver functionality

On 12/08/2012 18:40, Eric W. Biederman wrote:

Let me give you a non-hack recomendation.

- Give up on being wire compatible with IPoIB.

- Define and implement ethernet over inifiniband aka EoIB.

With EoIB:
- The SM would map ethernet address to inifiniband hardware addresses.
- You discover which multicast addresses are of interest from the
   IP layer above so no snooping is necessary.
- You could run queue pairs directly to hosts.

Shrug.  It is trivial and it will work.  It will probably run into the
same problems that have historically been a problem for using IPoIB
(lack of stateless offloads) but shrug that is mostly a NIC firmware
problem.  The switches will have no trouble and interoperability will
be assured.

If you want to map ethernet over infiniband please map ethernet over
infiniband.  Don't poorly NAT ethernet into infiniband.

EoIB is a valid suggestion and we will look into it as well, BUT:

Providing EoIB is a separate discussion, obviously defining and 
standardizing a new protocol takes what is takes (a lot of time, longish 
term effort), and will also take time to develop/debug/mature e.g as you 
mentioned, some of the features/offloads might require new NIC HW, etc 
-- compared to IPoIB which is here for many years

In practice there is already a huge install base for IPoIB software and 
hardware products, in different operating environments/OS. We can't just 
through away everything and tell people to replace it all with a new 
protocol, e.g. bridging devices, storage systems/appliances, VMware, 
Windows, .. systems in production environments --- so
the interoperability concern you've mentioned gonna hit very hard.

The eIPoIB driver comes to provide a way to work with IPoIB in 
virtualized environments, where still, the suggestions/concerns raised 
in this thread should be addressed.

Or.