Re: [Qemu-devel] [RFC PATCH RDMA support v3: 03/10] documentation of RDMA protocol in docs/rdma.txt

[Michael S. Tsirkin]

On Mon, Mar 11, 2013 at 01:17:19PM -0400, Michael R. Hines wrote:
> On 03/11/2013 01:05 PM, Michael S. Tsirkin wrote:
> >Well that's exactly the question. As far as I remember the RDMA
> >memory model, you need to know a key and address to execute RDMA
> >writes. Remote memory also needs to be locked, so you need some
> >mechanism to lock chunks of memory, do RDMA write and unlock when
> >done.
> 
> Yes, memory is registered before the write occurs - that's is all
> taken care of in rdma.c (patch #04/10)
> 
> Same answer for the SEND messages: memory for each send must be
> registered before you send.
> 
> The pinning (mlock()) is already handled by libibverbs (by calling
> the function ibv_reg_mr()) - standard infiniband protocol
> initialization.
> 
> - Michael

Yes but the document should describe when is the destination
memory registered and how are keys/addresses passed back to
source.