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

["Burakov, Anatoly" <anatoly.burakov@intel.com>]

On 7/4/2023 12:48 AM, Stephen Hemminger wrote:
> On Thu, 2 Jun 2022 10:23:07 +0200
> David Marchand <david.marchand@redhat.com> wrote:
> 
>> Hello Anatoly,
>>
>> On Tue, Nov 2, 2021 at 4:54 PM Burakov, Anatoly
>> <anatoly.burakov@intel.com> wrote:
>>>
>>> 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@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.
>>
>> It seems this patch fell through the cracks.
>> Any update?
>>
>> Thanks.
> 
> It is not clear what problem this is trying to solve.
> Is it for some hardware platform that is not available?
> Any updates on this patch or should it just be dropped?
> 

This should probably be dropped, because I believe there was already 
another patch that makes all mappings as page-by-page.

-- 
Thanks,
Anatoly