Re: [PATCH] netmap: support git-submodule build otption

[Peter Maydell]

On Fri, 4 Oct 2019 at 14:03, Giuseppe Lettieri <address@hidden> wrote:
>
> From: Giuseppe Lettieri <address@hidden>
>
> With this patch, netmap support can be enabled with
> the following options to the configure script:
>
>   --enable-netmap[=system]
>
>         Use the host system netmap installation.
>         Fail if not found.
>
>   --enable-netmap=git
>
>         clone the official netmap repository on
>         github (mostly useful for CI)
>
> Signed-off-by: Giuseppe Lettieri <address@hidden>
> ---
>  .gitmodules |  3 +++
>  configure   | 64 +++++++++++++++++++++++++++++++++++++++++++++--------
>  2 files changed, 58 insertions(+), 9 deletions(-)
>
> diff --git a/.gitmodules b/.gitmodules
> index c5c474169d..bf75dbc5e3 100644
> --- a/.gitmodules
> +++ b/.gitmodules
> @@ -58,3 +58,6 @@
>  [submodule "roms/opensbi"]
>         path = roms/opensbi
>         url =   https://git.qemu.org/git/opensbi.git
> +[submodule "netmap"]
> +       path = netmap
> +       url = https://github.com/luigirizzo/netmap.git

Hi; this patch seems to be missing the rationale for why
we want to do this. New submodules:
 * should always be on git.qemu.org (we need to mirror them
in case the original upstream vanishes)
 * need a strong justification for why they're required
(ie why we can't just use whatever the system-provided
version of the library is, or fall back to not providing
the feature if the library isn't present)

Basically new submodules are a pain so we seek to minimize
the use of them.

thanks
-- PMM