[dpdk-dev] [PATCH v2 1/1] vfio: add page-by-page mapping API

[Burakov, Anatoly]

On 28-Oct-21 3:09 PM, Anatoly Burakov wrote:
> Currently, there is no way to map memory for DMA in a way that allows
> unmapping it partially later, because some IOMMU's do not support
> partial unmapping. There is a workaround of mapping all of these
> segments separately, but this is inconvenient and silly, so this
> commit adds a proper API that does it.
> 
> This commit relies on earlier infrastructure that was built out to
> support "chunking", as the concept of "chunks" is essentially the same
> as page size.
> 
> Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
> ---
> 
> Notes:
>      v2:
>      - Added checks for page alignment of supplied values
>      - Added rte_errno values (similar to patch 103165 [1])
>      
>      [1] http://patches.dpdk.org/project/dpdk/patch/e8c5e7ba089e2283c3cd67e4529e52fe49390eb9.1635428963.git.anatoly.burakov@intel.com/

I think this API also needs VA and IOVA addresses in an array, so that 
it's possible to map IOVA-discontiguous segments. This is too late for 
this release, so let's postpone it till 22.02.

-- 
Thanks,
Anatoly