Re: [PATCH v3 01/11] tap: Remove tap_probe_vnet_hdr_len()

[Jason Wang]

On Fri, Oct 13, 2023 at 12:14 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> On 2023/10/13 10:38, Jason Wang wrote:
> > On Wed, Oct 11, 2023 at 11:40 PM Akihiko Odaki <akihiko.odaki@daynix.com> 
> > wrote:
> >>
> >> It was necessary since an Linux older than 2.6.35 may implement the
> >> virtio-net header but may not allow to change its length. Remove it
> >> since such an old Linux is no longer supported.
> >
> > Where can I see this agreement?
>
> docs/about/build-platforms.rst says:
>  > The project aims to support the most recent major version at all times
>  > for up to five years after its initial release. Support for the
>  > previous major version will be dropped 2 years after the new major
>  > version is released or when the vendor itself drops support, whichever
>  > comes first. In this context, third-party efforts to extend the
>  > lifetime of a distro are not considered, even when they are endorsed
>  > by the vendor (eg. Debian LTS); the same is true of repositories that
>  > contain packages backported from later releases (e.g. Debian
>  > backports). Within each major release, only the most recent minor
>  > release is considered.
>  >
>  > For the purposes of identifying supported software versions available
>  > on Linux, the project will look at CentOS, Debian, Fedora, openSUSE,
>  > RHEL, SLES and Ubuntu LTS. Other distros will be assumed to ship
>  > similar software versions.

Well it also says:

"""
If a platform is not listed here, it does not imply that QEMU won't
work. If an unlisted platform has comparable software versions to a
listed platform, there is every expectation that it will work.
"""

A lot of downstream have customized build scripts.

And is something similar to such removal that has been done for other
subsystems?

Thanks

>
> All of the previous major versions of these distributions ship far newer
> kernels.
>
> CentOS Stream 8 and RHEL 8 ship 4.18.0.
> Debian bullseye ships 5.10.0.
> Fedora 37 ships 6.5.6.
> openSUSE Leap 15.4 ships 5.14.21.
> SLES 12 ships 4.12.14.
> Ubuntu 20.04 ships 5.4.
>