[PATCH] dma/idxd: add allow/block list support

[Bruce Richardson]

On Tue, Nov 30, 2021 at 09:54:39AM +0000, Radu Nicolau wrote:
> Add support for allow or block list for devices bound
> to the kernel driver.
> When used the allow or block list applies as an additional
> condition to the name prefix.
> 
> Signed-off-by: Radu Nicolau <radu.nicolau at intel.com>
Reviewed-by: Bruce Richardson <bruce.richardson at intel.com>
Acked-by: Bruce Richardson <bruce.richardson at intel.com>

Minor comments inline below.
> ---
>  doc/guides/dmadevs/idxd.rst | 10 ++++++++++
>  drivers/dma/idxd/idxd_bus.c | 30 ++++++++++++++++++++++++++----
>  2 files changed, 36 insertions(+), 4 deletions(-)
> 
> diff --git a/doc/guides/dmadevs/idxd.rst b/doc/guides/dmadevs/idxd.rst
> index d4a210b854..6201d4db1d 100644
> --- a/doc/guides/dmadevs/idxd.rst
> +++ b/doc/guides/dmadevs/idxd.rst
> @@ -117,6 +117,16 @@ the value used as the DPDK ``--file-prefix`` parameter may be used as a workqueu
>  name prefix, instead of ``dpdk_``, allowing each DPDK application instance to only
>  use a subset of configured queues.
>  
> +Additionally, the -a (allowlist) or -b (blocklist) commandline parameters are
> +also available to further restrict the device list that will be used.
> +If the -a option is used then any device that passes the ``dpdk_`` or
Should probably have a comma after "used", and then you can split the line
at that point, having the rest of the sentence on one line. I believe
longer lines are allowed for docs so long as we split them at punctuation
points.

> +``--file-prefix`` prefix condition must also be present in the allow list.
> +Similarly, when the block list is used any device that passes the prefix
> +condition must not be in the block list.
Similarly for this sentence, can put comma and break after "used".

> +For example, to only use ``wq0.3``, assuming the name prefix condition is met::
> +
> +	$ dpdk-test -a wq0.3
> +
>  Once probed successfully, irrespective of kernel driver, the device will appear as a ``dmadev``,
>  that is a "DMA device type" inside DPDK, and can be accessed using APIs from the
>  ``rte_dmadev`` library.
<snip>