Re: [SPDK] SPDK failed to access CMB cards

[Walker, Benjamin <benjamin.walker at intel.com>]

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On Mon, 2018-06-18 at 20:33 +0530, Srinath Mannam wrote:
> Outbound mapping in our platforms, CPU address is not same as PCI bus address.
> If we program CPU address (CMB bar physical address) as SQ address. then CMB
> card will send read request  to corresponding CPU address over PCIe bus, which
> is invalid inbound address to our RC so it is rejected as UR.
> 
> For the same issue, we have a fix in kernel driver. The fix is, SQ address has
> to configure rather PCI bus address than CPU address.
> In this case CMB card read SQ from its local memory (CMB bar memory) without
> generating memory read on PCIe bus.
> 
> We need same type of fix in spdk nvme library also.
> 
> We think two different solutions to solve this issue.
> 1. Get PCI bus address to corresponding CPU address (SMB bar address) through
> sysfs entry, in the same way we get BAR phy address with the read of
> "resource" file in sysfs. This case we program PCI bus address as SQ address. 
> This fix is similar to the kernel driver fix. 

Which sysfs entry contains the proper address?

Thanks,
Ben