[openib-general] mthca FMR correctness (and memory windows)

[Talpey, Thomas]

At 08:42 PM 3/20/2006, Diego Crupnicoff wrote:
>> If I can snoop or guess rkeys (not a huge challenge with 32 bits), and 
>> if I can use them on an arbitrary queuepair, then I can handily peek and 
>> poke at memory that does not belong to me. 
>
>No. You can't get to the Window from an arbitrary QP. Only from those QPs that belong to the same PD. 


Oh yeah, I have to guess the PD too.

>> For this reason, iWARP requires its steering tags to be scoped to a single 
>> connection. This leverages the IP security model and provides correctness. 
>> 
>> It is true that IB implementations generally don't do this. They should. 
>
>IB allows the 2 flavors (PD bound Windows aka type 1, and QP bound Windows aka type 2). 

Does mthca? I thought it's all type 1.

Tom.