[openib-general] MTHCA features

[James Lentini]

roland>     James> It is my understanding that the current MTHCA driver does
roland>     James> not support InfiniBand memory windows or memory
roland>     James> registration using virtual addresses.
roland> 
roland>     James> Is this information correct? If so, when will these
roland>     James> features be supported?
roland> 
roland> Well, memory registration is pretty complete.  By design, we only
roland> support memory registration with physical addresses for kernel
roland> consumers even at the verbs API level (ie there are no mthca-specific
roland> limitations).  In the kernel, registration by virtual address is not
roland> very useful.  For userspace verbs, only registration by virtual
roland> address is supported for obvious reasons.
roland> 
roland> Memory windows are not implemented for mthca.  It wouldn't be a lot of
roland> work for someone with access to Mellanox documentation to implement
roland> them, but they're not particularly useful due to their performance
roland> characteristics.

Is anyone on this list working on memory window support? 

I ask because the DAT API contains interfaces that allow users to 
interact with memory windows.