Hi Ferruh,

-----Original Message-----
From: Yigit, Ferruh <redacted>
Sent: Wednesday, September 1, 2021 12:01 AM
To: Ding, Xuan <redacted>; dev@dpdk.org; Burakov, Anatoly
[off-list ref]
Cc: maxime.coquelin@redhat.com; Xia, Chenbo <redacted>; Hu,
Jiayu [off-list ref]; Richardson, Bruce [off-list ref]
Subject: Re: [PATCH] doc: announce change in vfio dma mapping

On 8/31/2021 2:10 PM, Xuan Ding wrote:

quoted

Currently, the VFIO subsystem will compact adjacent DMA regions for the
purposes of saving space in the internal list of mappings. This has a
side effect of compacting two separate mappings that just happen to be
adjacent in memory. Since VFIO implementation on IA platforms also does
not allow partial unmapping of memory mapped for DMA, the current

DPDK

quoted

VFIO implementation will prevent unmapping of accidentally adjacent
maps even though it could have been unmapped [1].

The proper fix for this issue is to change the VFIO DMA mapping API to
also include page size, and always map memory page-by-page.

[1] https://mails.dpdk.org/archives/dev/2021-July/213493.html

Signed-off-by: Xuan Ding <redacted>
---
 doc/guides/rel_notes/deprecation.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/doc/guides/rel_notes/deprecation.rst

b/doc/guides/rel_notes/deprecation.rst

quoted

index 76a4abfd6b..1234420caf 100644

--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst

@@ -287,3 +287,6 @@ Deprecation Notices
   reserved bytes to 2 (from 3), and use 1 byte to indicate warnings and

other

quoted

   information from the crypto/security operation. This field will be used to
   communicate events such as soft expiry with IPsec in lookaside mode.
+
+* vfio: the functions `rte_vfio_container_dma_map` will be amended to
+  include page size. This change is targeted for DPDK 22.02.

Is this means adding a new parameter to API?
If so this is an ABI/API break and we can't do this change in the 22.02.

Our original plan is add a new parameter in order not to use a new function name, so you mean, any changes to the API can only be done in the LTS version?
If so, we can only add a new API and retire the old one in 22.11.

Thanks for you classification.