[PATCH] net/intel: deprecate some SSE paths

[PATCH] net/intel: deprecate some SSE paths

[Ciara Loftus]

The SSE rx and tx paths will be removed from the i40e, iavf and ice
drivers in the 25.11 release. Each of these drivers have faster vector
paths (AVX2 and AVX-512) which have feature parity with the soon to be
removed SSE paths. In environments where AVX2 or AVX-512 are not
supported, the scalar path will still be used, which also has feature
parity.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
 doc/guides/rel_notes/deprecation.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index e2d4125308..7b9b6beaa5 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -80,6 +80,11 @@ Deprecation Notices
   and the header struct ``rte_vxlan_gpe_hdr`` with the macro ``RTE_ETHER_VXLAN_GPE_HLEN``
   will be removed in DPDK 25.11.
 
+* net/intel: drivers that have an SSE vector path alongside other vector paths, namely
+  i40e, iavf and ice, will have their SSE vector paths removed in DPDK 25.11. This change
+  will not result in any feature loss, as the fallback scalar paths which have feature
+  parity with SSE will be used in the cases where the SSE paths would have been used.
+
 * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
   should start with relevant protocol header structure from lib/net/.
   The individual protocol header fields and the protocol header struct
-- 
2.34.1

Re: [PATCH] net/intel: deprecate some SSE paths

[Bruce Richardson]

On Thu, Jul 03, 2025 at 12:16:24PM +0000, Ciara Loftus wrote:
> The SSE rx and tx paths will be removed from the i40e, iavf and ice
> drivers in the 25.11 release. Each of these drivers have faster vector
> paths (AVX2 and AVX-512) which have feature parity with the soon to be
> removed SSE paths. In environments where AVX2 or AVX-512 are not
> supported, the scalar path will still be used, which also has feature
> parity.
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> ---
>  doc/guides/rel_notes/deprecation.rst | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> index e2d4125308..7b9b6beaa5 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -80,6 +80,11 @@ Deprecation Notices
>    and the header struct ``rte_vxlan_gpe_hdr`` with the macro ``RTE_ETHER_VXLAN_GPE_HLEN``
>    will be removed in DPDK 25.11.
>  
> +* net/intel: drivers that have an SSE vector path alongside other vector paths, namely
> +  i40e, iavf and ice, will have their SSE vector paths removed in DPDK 25.11. This change
> +  will not result in any feature loss, as the fallback scalar paths which have feature
> +  parity with SSE will be used in the cases where the SSE paths would have been used.
> +

Hi Ciara,

I think it would be good to mention AVX in the deprecation notice as well
as in the commit log, since it's not as though we are removing the SSE to
have all apps drop down to scalar. Instead, it's being deprecated because
modern x86 systems all support AVX2, if not AXV-512, so SSE code path
should be unnecessary in new deployments.

/Bruce

>  * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
>    should start with relevant protocol header structure from lib/net/.
>    The individual protocol header fields and the protocol header struct
> -- 
> 2.34.1
> 

[PATCH v2] net/intel: deprecate some SSE paths

[Ciara Loftus]

The SSE rx and tx paths will be removed from the i40e, iavf and ice
drivers in the 25.11 release. Each of these drivers have faster vector
paths (AVX2 and AVX-512) which have feature parity with the soon to be
removed SSE paths. In environments where AVX2 or AVX-512 are not
supported, the scalar path will still be used, which also has feature
parity.

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
 doc/guides/rel_notes/deprecation.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
index e2d4125308..0d020c9c1f 100644
--- a/doc/guides/rel_notes/deprecation.rst
+++ b/doc/guides/rel_notes/deprecation.rst
@@ -80,6 +80,13 @@ Deprecation Notices
   and the header struct ``rte_vxlan_gpe_hdr`` with the macro ``RTE_ETHER_VXLAN_GPE_HLEN``
   will be removed in DPDK 25.11.
 
+* net/intel: drivers that have an SSE vector path alongside other vector paths,
+  namely i40e, iavf and ice, will have their SSE vector paths removed in DPDK 25.11.
+  Modern x86 systems all support AVX2, if not AVX-512, so the SSE path is no longer
+  widely used. This change will not result in any feature loss, as the fallback
+  scalar paths which have feature parity with SSE will be used in the cases where
+  the SSE paths would have been used.
+
 * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
   should start with relevant protocol header structure from lib/net/.
   The individual protocol header fields and the protocol header struct
-- 
2.34.1

Re: [PATCH v2] net/intel: deprecate some SSE paths

[Bruce Richardson]

On Thu, Jul 03, 2025 at 02:31:19PM +0000, Ciara Loftus wrote:
> The SSE rx and tx paths will be removed from the i40e, iavf and ice
> drivers in the 25.11 release. Each of these drivers have faster vector
> paths (AVX2 and AVX-512) which have feature parity with the soon to be
> removed SSE paths. In environments where AVX2 or AVX-512 are not
> supported, the scalar path will still be used, which also has feature
> parity.
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> ---
>  doc/guides/rel_notes/deprecation.rst | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> index e2d4125308..0d020c9c1f 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -80,6 +80,13 @@ Deprecation Notices
>    and the header struct ``rte_vxlan_gpe_hdr`` with the macro ``RTE_ETHER_VXLAN_GPE_HLEN``
>    will be removed in DPDK 25.11.
>  
> +* net/intel: drivers that have an SSE vector path alongside other vector paths,
> +  namely i40e, iavf and ice, will have their SSE vector paths removed in DPDK 25.11.
> +  Modern x86 systems all support AVX2, if not AVX-512, so the SSE path is no longer
> +  widely used. This change will not result in any feature loss, as the fallback
> +  scalar paths which have feature parity with SSE will be used in the cases where
> +  the SSE paths would have been used.
> +

Acked-by: Bruce Richardson <bruce.richardson@intel.com>

RE: [PATCH v2] net/intel: deprecate some SSE paths

[Konstantin Ananyev]

> The SSE rx and tx paths will be removed from the i40e, iavf and ice
> drivers in the 25.11 release. Each of these drivers have faster vector
> paths (AVX2 and AVX-512) which have feature parity with the soon to be
> removed SSE paths. In environments where AVX2 or AVX-512 are not
> supported, the scalar path will still be used, which also has feature
> parity.
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> ---
>  doc/guides/rel_notes/deprecation.rst | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> index e2d4125308..0d020c9c1f 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -80,6 +80,13 @@ Deprecation Notices
>    and the header struct ``rte_vxlan_gpe_hdr`` with the macro ``RTE_ETHER_VXLAN_GPE_HLEN``
>    will be removed in DPDK 25.11.
> 
> +* net/intel: drivers that have an SSE vector path alongside other vector paths,
> +  namely i40e, iavf and ice, will have their SSE vector paths removed in DPDK 25.11.
> +  Modern x86 systems all support AVX2, if not AVX-512, so the SSE path is no longer
> +  widely used. This change will not result in any feature loss, as the fallback
> +  scalar paths which have feature parity with SSE will be used in the cases where
> +  the SSE paths would have been used.
> +
>  * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
>    should start with relevant protocol header structure from lib/net/.
>    The individual protocol header fields and the protocol header struct
> --

Acked-by: Konstantin Ananyev <konstantin.ananyev@huawei.com> 

> 2.34.1

Re: [PATCH v2] net/intel: deprecate some SSE paths

[Kevin Traynor]

On 03/07/2025 15:31, Ciara Loftus wrote:
> The SSE rx and tx paths will be removed from the i40e, iavf and ice
> drivers in the 25.11 release. Each of these drivers have faster vector
> paths (AVX2 and AVX-512) which have feature parity with the soon to be
> removed SSE paths. In environments where AVX2 or AVX-512 are not
> supported, the scalar path will still be used, which also has feature
> parity.
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> ---
>  doc/guides/rel_notes/deprecation.rst | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> index e2d4125308..0d020c9c1f 100644
> --- a/doc/guides/rel_notes/deprecation.rst
> +++ b/doc/guides/rel_notes/deprecation.rst
> @@ -80,6 +80,13 @@ Deprecation Notices
>    and the header struct ``rte_vxlan_gpe_hdr`` with the macro ``RTE_ETHER_VXLAN_GPE_HLEN``
>    will be removed in DPDK 25.11.
>  
> +* net/intel: drivers that have an SSE vector path alongside other vector paths,
> +  namely i40e, iavf and ice, will have their SSE vector paths removed in DPDK 25.11.
> +  Modern x86 systems all support AVX2, if not AVX-512, so the SSE path is no longer
> +  widely used. This change will not result in any feature loss, as the fallback
> +  scalar paths which have feature parity with SSE will be used in the cases where
> +  the SSE paths would have been used.
> +
>  * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
>    should start with relevant protocol header structure from lib/net/.
>    The individual protocol header fields and the protocol header struct

I'm not aware of anyone using hardware that old and relying on SSE, but
it seems a bit short notice for a patch to remove hardware support.

Would it hurt much to give it a longer deprecation so anyone who needs
to prepare by upgrade, or taking 25.11 with support etc. can do that ?

Re: [PATCH v2] net/intel: deprecate some SSE paths

[Bruce Richardson]

On Fri, Jul 18, 2025 at 04:03:17PM +0100, Kevin Traynor wrote:
> On 03/07/2025 15:31, Ciara Loftus wrote:
> > The SSE rx and tx paths will be removed from the i40e, iavf and ice
> > drivers in the 25.11 release. Each of these drivers have faster vector
> > paths (AVX2 and AVX-512) which have feature parity with the soon to be
> > removed SSE paths. In environments where AVX2 or AVX-512 are not
> > supported, the scalar path will still be used, which also has feature
> > parity.
> > 
> > Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> > ---
> >  doc/guides/rel_notes/deprecation.rst | 7 +++++++
> >  1 file changed, 7 insertions(+)
> > 
> > diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> > index e2d4125308..0d020c9c1f 100644
> > --- a/doc/guides/rel_notes/deprecation.rst
> > +++ b/doc/guides/rel_notes/deprecation.rst
> > @@ -80,6 +80,13 @@ Deprecation Notices
> >    and the header struct ``rte_vxlan_gpe_hdr`` with the macro ``RTE_ETHER_VXLAN_GPE_HLEN``
> >    will be removed in DPDK 25.11.
> >  
> > +* net/intel: drivers that have an SSE vector path alongside other vector paths,
> > +  namely i40e, iavf and ice, will have their SSE vector paths removed in DPDK 25.11.
> > +  Modern x86 systems all support AVX2, if not AVX-512, so the SSE path is no longer
> > +  widely used. This change will not result in any feature loss, as the fallback
> > +  scalar paths which have feature parity with SSE will be used in the cases where
> > +  the SSE paths would have been used.
> > +
> >  * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
> >    should start with relevant protocol header structure from lib/net/.
> >    The individual protocol header fields and the protocol header struct
> 
> I'm not aware of anyone using hardware that old and relying on SSE, but
> it seems a bit short notice for a patch to remove hardware support.
> 
> Would it hurt much to give it a longer deprecation so anyone who needs
> to prepare by upgrade, or taking 25.11 with support etc. can do that ?
> 
Do we think that will make a difference? After all, dropping the SSE path
won't break DPDK on older hardware, it will only run a bit slower using the
scalar path. Beyond that, it would only affect deployments with new/latest
DPDK on old hardware - obviously old hardware running older DPDK would be
unaffected.

/Bruce

Re: [PATCH v2] net/intel: deprecate some SSE paths

[Kevin Traynor]

On 18/07/2025 16:19, Bruce Richardson wrote:
> On Fri, Jul 18, 2025 at 04:03:17PM +0100, Kevin Traynor wrote:
>> On 03/07/2025 15:31, Ciara Loftus wrote:
>>> The SSE rx and tx paths will be removed from the i40e, iavf and ice
>>> drivers in the 25.11 release. Each of these drivers have faster vector
>>> paths (AVX2 and AVX-512) which have feature parity with the soon to be
>>> removed SSE paths. In environments where AVX2 or AVX-512 are not
>>> supported, the scalar path will still be used, which also has feature
>>> parity.
>>>
>>> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
>>> ---
>>>  doc/guides/rel_notes/deprecation.rst | 7 +++++++
>>>  1 file changed, 7 insertions(+)
>>>
>>> diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
>>> index e2d4125308..0d020c9c1f 100644
>>> --- a/doc/guides/rel_notes/deprecation.rst
>>> +++ b/doc/guides/rel_notes/deprecation.rst
>>> @@ -80,6 +80,13 @@ Deprecation Notices
>>>    and the header struct ``rte_vxlan_gpe_hdr`` with the macro ``RTE_ETHER_VXLAN_GPE_HLEN``
>>>    will be removed in DPDK 25.11.
>>>  
>>> +* net/intel: drivers that have an SSE vector path alongside other vector paths,
>>> +  namely i40e, iavf and ice, will have their SSE vector paths removed in DPDK 25.11.
>>> +  Modern x86 systems all support AVX2, if not AVX-512, so the SSE path is no longer
>>> +  widely used. This change will not result in any feature loss, as the fallback
>>> +  scalar paths which have feature parity with SSE will be used in the cases where
>>> +  the SSE paths would have been used.
>>> +
>>>  * ethdev: The flow API matching pattern structures, ``struct rte_flow_item_*``,
>>>    should start with relevant protocol header structure from lib/net/.
>>>    The individual protocol header fields and the protocol header struct
>>
>> I'm not aware of anyone using hardware that old and relying on SSE, but
>> it seems a bit short notice for a patch to remove hardware support.
>>
>> Would it hurt much to give it a longer deprecation so anyone who needs
>> to prepare by upgrade, or taking 25.11 with support etc. can do that ?
>>
> Do we think that will make a difference? After all, dropping the SSE path
> won't break DPDK on older hardware, it will only run a bit slower using the
> scalar path. Beyond that, it would only affect deployments with new/latest
> DPDK on old hardware - obviously old hardware running older DPDK would be
> unaffected.
> 

Don't disagree, and it does seem a bit of mismatch using old hw and new
DPDK, but I needed to spend a bit of time to try and check if this would
impact wrt systems used, compile options, product upgrade paths etc. so
others might be in same boat.

Alternatively, could put the deprecation now and revisit if anyone
complains before 25.11.

> /Bruce
> 

Re: [PATCH v2] net/intel: deprecate some SSE paths

[Bruce Richardson]

On Fri, Jul 18, 2025 at 05:05:45PM +0100, Kevin Traynor wrote:
> On 18/07/2025 16:19, Bruce Richardson wrote:
> > On Fri, Jul 18, 2025 at 04:03:17PM +0100, Kevin Traynor wrote:
> >> On 03/07/2025 15:31, Ciara Loftus wrote:
> >>> The SSE rx and tx paths will be removed from the i40e, iavf and ice
> >>> drivers in the 25.11 release. Each of these drivers have faster
> >>> vector paths (AVX2 and AVX-512) which have feature parity with the
> >>> soon to be removed SSE paths. In environments where AVX2 or AVX-512
> >>> are not supported, the scalar path will still be used, which also has
> >>> feature parity.
> >>>
> >>> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> ---
> >>> doc/guides/rel_notes/deprecation.rst | 7 +++++++ 1 file changed, 7
> >>> insertions(+)
> >>>
> >>> diff --git a/doc/guides/rel_notes/deprecation.rst
> >>> b/doc/guides/rel_notes/deprecation.rst index e2d4125308..0d020c9c1f
> >>> 100644 --- a/doc/guides/rel_notes/deprecation.rst +++
> >>> b/doc/guides/rel_notes/deprecation.rst @@ -80,6 +80,13 @@ Deprecation
> >>> Notices and the header struct ``rte_vxlan_gpe_hdr`` with the macro
> >>> ``RTE_ETHER_VXLAN_GPE_HLEN`` will be removed in DPDK 25.11.
> >>>  
> >>> +* net/intel: drivers that have an SSE vector path alongside other
> >>> vector paths, +  namely i40e, iavf and ice, will have their SSE
> >>> vector paths removed in DPDK 25.11.  +  Modern x86 systems all
> >>> support AVX2, if not AVX-512, so the SSE path is no longer +  widely
> >>> used. This change will not result in any feature loss, as the
> >>> fallback +  scalar paths which have feature parity with SSE will be
> >>> used in the cases where +  the SSE paths would have been used.  + *
> >>> ethdev: The flow API matching pattern structures, ``struct
> >>> rte_flow_item_*``, should start with relevant protocol header
> >>> structure from lib/net/.  The individual protocol header fields and
> >>> the protocol header struct
> >>
> >> I'm not aware of anyone using hardware that old and relying on SSE,
> >> but it seems a bit short notice for a patch to remove hardware
> >> support.
> >>
> >> Would it hurt much to give it a longer deprecation so anyone who needs
> >> to prepare by upgrade, or taking 25.11 with support etc. can do that ?
> >>
> > Do we think that will make a difference? After all, dropping the SSE
> > path won't break DPDK on older hardware, it will only run a bit slower
> > using the scalar path. Beyond that, it would only affect deployments
> > with new/latest DPDK on old hardware - obviously old hardware running
> > older DPDK would be unaffected.
> > 
> 
> Don't disagree, and it does seem a bit of mismatch using old hw and new
> DPDK, but I needed to spend a bit of time to try and check if this would
> impact wrt systems used, compile options, product upgrade paths etc. so
> others might be in same boat.
> 
> Alternatively, could put the deprecation now and revisit if anyone
> complains before 25.11.
> 
Sure. Let's deprecate now and if there are any objections or we decide to
postpone the removal in 25.11 that is fine.

/Bruce

Re: [PATCH v2] net/intel: deprecate some SSE paths

[Kevin Traynor]

On 18/07/2025 17:13, Bruce Richardson wrote:
> On Fri, Jul 18, 2025 at 05:05:45PM +0100, Kevin Traynor wrote:
>> On 18/07/2025 16:19, Bruce Richardson wrote:
>>> On Fri, Jul 18, 2025 at 04:03:17PM +0100, Kevin Traynor wrote:
>>>> On 03/07/2025 15:31, Ciara Loftus wrote:
>>>>> The SSE rx and tx paths will be removed from the i40e, iavf and ice
>>>>> drivers in the 25.11 release. Each of these drivers have faster
>>>>> vector paths (AVX2 and AVX-512) which have feature parity with the
>>>>> soon to be removed SSE paths. In environments where AVX2 or AVX-512
>>>>> are not supported, the scalar path will still be used, which also has
>>>>> feature parity.
>>>>>
>>>>> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com> ---
>>>>> doc/guides/rel_notes/deprecation.rst | 7 +++++++ 1 file changed, 7
>>>>> insertions(+)
>>>>>
>>>>> diff --git a/doc/guides/rel_notes/deprecation.rst
>>>>> b/doc/guides/rel_notes/deprecation.rst index e2d4125308..0d020c9c1f
>>>>> 100644 --- a/doc/guides/rel_notes/deprecation.rst +++
>>>>> b/doc/guides/rel_notes/deprecation.rst @@ -80,6 +80,13 @@ Deprecation
>>>>> Notices and the header struct ``rte_vxlan_gpe_hdr`` with the macro
>>>>> ``RTE_ETHER_VXLAN_GPE_HLEN`` will be removed in DPDK 25.11.
>>>>>  
>>>>> +* net/intel: drivers that have an SSE vector path alongside other
>>>>> vector paths, +  namely i40e, iavf and ice, will have their SSE
>>>>> vector paths removed in DPDK 25.11.  +  Modern x86 systems all
>>>>> support AVX2, if not AVX-512, so the SSE path is no longer +  widely
>>>>> used. This change will not result in any feature loss, as the
>>>>> fallback +  scalar paths which have feature parity with SSE will be
>>>>> used in the cases where +  the SSE paths would have been used.  + *
>>>>> ethdev: The flow API matching pattern structures, ``struct
>>>>> rte_flow_item_*``, should start with relevant protocol header
>>>>> structure from lib/net/.  The individual protocol header fields and
>>>>> the protocol header struct
>>>>
>>>> I'm not aware of anyone using hardware that old and relying on SSE,
>>>> but it seems a bit short notice for a patch to remove hardware
>>>> support.
>>>>
>>>> Would it hurt much to give it a longer deprecation so anyone who needs
>>>> to prepare by upgrade, or taking 25.11 with support etc. can do that ?
>>>>
>>> Do we think that will make a difference? After all, dropping the SSE
>>> path won't break DPDK on older hardware, it will only run a bit slower
>>> using the scalar path. Beyond that, it would only affect deployments
>>> with new/latest DPDK on old hardware - obviously old hardware running
>>> older DPDK would be unaffected.
>>>
>>
>> Don't disagree, and it does seem a bit of mismatch using old hw and new
>> DPDK, but I needed to spend a bit of time to try and check if this would
>> impact wrt systems used, compile options, product upgrade paths etc. so
>> others might be in same boat.
>>
>> Alternatively, could put the deprecation now and revisit if anyone
>> complains before 25.11.
>>
> Sure. Let's deprecate now and if there are any objections or we decide to
> postpone the removal in 25.11 that is fine.
> 

Sounds good.

Acked-by: Kevin Traynor <ktraynor@redhat.com>

> /Bruce
>