RE: [PATCH v2 1/5] build: add meson option to configure IOVA mode as VA

["Morten Brørup" <mb@smartsharesystems.com>]

> From: Bruce Richardson [mailto:bruce.richardson@intel.com]
> Sent: Wednesday, 7 September 2022 17.38
> 
> On Wed, Sep 07, 2022 at 08:31:09AM -0700, Stephen Hemminger wrote:
> > On Wed, 7 Sep 2022 19:13:36 +0530 Shijith Thotton
> <sthotton@marvell.com>
> > wrote:
> >
> > > IOVA mode in DPDK is either PA or VA. The new build option
> iova_as_va
> > > configures the mode to VA at compile time and prevents setting it
> to PA
> > > at runtime. For now, all drivers which are not always enabled are
> > > disabled with this option. Supported driver can set the flag
> > > pmd_iova_as_va in its build file to enable build.
> > >
> > > mbuf structure holds the physical (PA) and virtual address (VA) of
> a
> > > buffer. if IOVA mode is set to VA, PA is redundant as it is the
> same as
> > > VA. So PA field need not be updated and marked invalid if the build
> is
> > > configured to use only VA.
> > >
> > > Signed-off-by: Shijith Thotton <sthotton@marvell.com>
> >
> > NAK This works ok for use cases where NFV is building local version
> of
> > DPDK, but meson options dont work for distro vendors.
> >
> I think for something of this magnitude a build-time option is
> definitely
> the way to go. Sure, it won't be available in distro-packages, but for
> something like this it's just too invasive - and rather niche IMHO - to
> make a runtime option.
+1