[PATCH] drivers: skip build of sub-libs not supporting IOVA mode

[Thomas Monjalon]

02/03/2023 14:52, Zhang, Qi Z:
> From: Thomas Monjalon <thomas at monjalon.net>
> > If IOVA as PA is disabled and the driver does not support IOVA as VA, the
> > build of the driver was disabled.
> > Unfortunately some drivers were building some sub-libraries (with specific
> > options for vector paths) which were not disabled.
> > 
> > The build parsing of those drivers need to be skipped earlier to avoid
> > defining the sub-libraries.
> > 
> > Fixes: a986c2b7973d ("build: add option to configure IOVA mode as PA")
> > Cc: stable at dpdk.org
> > 
> > Signed-off-by: Thomas Monjalon <thomas at monjalon.net>
[...]
> > --- a/drivers/meson.build
> > +++ b/drivers/meson.build
> > @@ -127,9 +127,9 @@ foreach subpath:subdirs
> >              # pull in driver directory which should update all the local variables
> >              subdir(drv_path)
> > 
> > -            if dpdk_conf.get('RTE_IOVA_AS_PA') == 0 and not
> > pmd_supports_disable_iova_as_pa and not
> > always_enable.contains(drv_path)
> > +            if not get_option('enable_iova_as_pa') and not
> > + pmd_supports_disable_iova_as_pa and not
> > + always_enable.contains(drv_path)
> >                  build = false
> > -                reason = 'driver does not support disabling IOVA as PA mode'
> > +                reason = 'IOVA as VA not supported'
> >              endif
> 
> If we check enable_iova_as_pa for each unsupported driver , do we still need "pmd_supports_disable_iova_as_pa"?

They are a bit redundant.
The idea is to use pmd_supports_disable_iova_as_pa (could be renamed)
as it is simpler to use.
But in the case of drivers having sub-libs (always enabled),
we need an extra check of enable_iova_as_pa inside the driver file.