Re: [Scst-devel] vm sr-iov ib_srpt MAD registration failed for mlx4_0-1

[Nate P. <dar...@da...>]

>> 
>> Should I not expect this to work?  The module loads but can’t use the IB.
> 
> Hello Nate,
> 
> I think that sending MADs (management datagrams) over a VF (PCIe virtual function) is supported but receiving MADs not. That is why the above error message appears when trying to load ib_srpt in a VM that accesses a Mellanox card via SR-IOV. Would one of the following approaches work for you ?
> - Change the last statement in srpt_refresh_port() from "return ret"
>  into "return 0" on the target system. Disable srptools on the
>  initiator system and write into sysfs attributes like
>  /sys/class/infiniband_srp/srp-mlx4_0-1/add_target to trigger login.
>  The login information can be found on the target in the
>  /sys/kernel/scst_tgt/targets/ib_srpt/${port}/login_info attributes.
> - Use PCIe pass-through instead of SR-IOV to allow the VM to access the
>  HCA.
> 
> Bart.


Hi Bart,

Thanks for the quick reply!

My goal here is to export mhvtl tape changers and devices via srp.  I don’t believe disabling srptools on the initiators is something I’d *like* to do, but I may be able to try it out.

It’s not clear to me how to make the HCA available via PCIe pass-through w/o using SR-IOV especially since I’d like the host to use the IB and it’s running opensm.  I may just have to put my vtl on real hw.