[PATCH v2 1/2] build: clarify configuration without IOVA field in mbuf

[fengchengwen]

On 2023/3/7 0:13, Thomas Monjalon wrote:
> The impact of the option "enable_iova_as_pa" is explained for users.
> 
> Also the code flag "RTE_IOVA_AS_PA" is renamed as "RTE_IOVA_IN_MBUF"
> in order to be more accurate (IOVA mode is decided at runtime),
> and more readable in the code.
> 
> Similarly the drivers are using the variable "require_iova_in_mbuf"
> instead of "pmd_supports_disable_iova_as_pa" with an opposite meaning.
> By default, it is assumed that drivers require the IOVA field in mbuf.
> The drivers which support removing this field have to declare themselves.
> 
> If the option "enable_iova_as_pa" is disabled, the unsupported drivers
> will be listed with the new reason text "requires IOVA in mbuf".
> 
> Suggested-by: Bruce Richardson <bruce.richardson at intel.com>
> Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
> ---

...

>  compile_time_cpuflags = []
>  subdir(arch_subdir)
> diff --git a/doc/guides/rel_notes/release_22_11.rst b/doc/guides/rel_notes/release_22_11.rst
> index 91414573bd..c67c2823a2 100644
> --- a/doc/guides/rel_notes/release_22_11.rst
> +++ b/doc/guides/rel_notes/release_22_11.rst
> @@ -504,7 +504,7 @@ ABI Changes
>    ``rte-worker-<lcore_id>`` so that DPDK can accommodate lcores higher than 99.
>  
>  * mbuf: Replaced ``buf_iova`` field with ``next`` field and added a new field
> -  ``dynfield2`` at its place in second cacheline if ``RTE_IOVA_AS_PA`` is 0.
> +  ``dynfield2`` at its place in second cacheline if ``RTE_IOVA_IN_MBUF`` is 0.

Should add to release 23.03 rst.
The original 22.11 still have RTE_IOVA_AS_PA definition.

...

> diff --git a/drivers/net/hns3/meson.build b/drivers/net/hns3/meson.build
> index e1a5afa2ec..743fae9db7 100644
> --- a/drivers/net/hns3/meson.build
> +++ b/drivers/net/hns3/meson.build
> @@ -13,9 +13,7 @@ if arch_subdir != 'x86' and arch_subdir != 'arm' or not dpdk_conf.get('RTE_ARCH_
>      subdir_done()
>  endif
>  
> -if dpdk_conf.get('RTE_IOVA_AS_PA') == 0
> -    build = false
> -    reason = 'driver does not support disabling IOVA as PA mode'
> +if not get_option('enable_iova_as_pa')
>      subdir_done()
>  endif

Suggest keep original, and replace RTE_IOVA_AS_PA with RTE_IOVA_IN_MBUF:
if dpdk_conf.get('RTE_IOVA_IN_MBUF') == 0
     subdir_done()
endif
Meson build 0.63.0 already support deprecated a option by a new option.
When update to the new meson verion, the drivers' meson.build will not be modified.

>  
> diff --git a/drivers/net/ice/ice_rxtx_common_avx.h b/drivers/net/ice/ice_rxtx_common_avx.h
> index e69e23997f..dacb87dcb0 100644

...