Re: [PATCH v5 00/13] Copy Offload in NVMe Fabrics with P2P PCI Memory

On Thu, Aug 30, 2018 at 12:53:39PM -0600, Logan Gunthorpe wrote:

[...]

When the PCI P2PDMA config option is selected the ACS bits in every
bridge port in the system are turned off to allow traffic to
pass freely behind the root port. At this time, the bit must be disabled
at boot so the IOMMU subsystem can correctly create the groups, though
this could be addressed in the future. There is no way to dynamically
disable the bit and alter the groups.

Can you provide an example on how to test this ? Like kernel command
line option, the doc patch does not have any such example. It would be
nice to add.

Maybe i have miss it in some of the patch. I just skimmed over for
now.

Cheers,
J�r�me