[openib-general] [PATCH 1/7] IB/core - Add DMA mapping functions to allow device drivers to interpose

[Steve Wise]

> > 
> > But how?
> > Wait, work request posting functions actually get a virtual
> > address and a key, not a dma address. 
> 
> Work requests posted using ib_post_send/recv are specified using a dma 
> address obtained using the appropriate Linux DMA mapping API function. 
> They are not virtual addresses.
> 

This isn't necessarily true.  The addr field in the WR is a dma addr
when using a MR allocated via ib_get_dma_mr().  For MRs allocated via
ib_reg_phys_mem(), then the addr field is something relative to the
iova_start u64 passed into the ib_reg_phys_mem().  Right?