Re: Problem Pinning Physical Memory

Eli Cohen
2010-11-24T13:55:07Z

On Mon, Nov 22, 2010 at 06:28:47PM +0000, Brian wrote:
> ibv_reg_mr works fine as long as the shared region is in RAM. However, if I
> change the memory region to the physical memory on a PCI device the call to
> ibv_reg_mr fails. What should I be doing to register a physical memory region?
>
> In searching through this forum I've seen some patches relating to
> reg_io_mr/dereg_io_mr. However, I don't see those changes in the 1.5.2 ofed
> sources. I had hoped to try applying the patches myself but the structure of the
> unchanged code in the patches appears to be different than the 1.5.2 ofed
> sources. Is there another, more recent, code base that I should be using?
>

You can't regiter IO memory using ibv_reg_mr() - you can only do that
by registering that memory using physical memory registration which is
available only for kernel consumers. You can't allow userspace to
register physical pages as this is a security breach.