On Fri, Oct 13, 2023 at 02:26:03PM +0900, Akihiko Odaki wrote: > On 2023/10/13 14:00, Jason Wang wrote: > > On Fri, Oct 13, 2023 at 12:14 PM Akihiko Odaki <akihiko.od...@daynix.com> > > wrote: > > > > > > On 2023/10/13 10:38, Jason Wang wrote: > > > > On Wed, Oct 11, 2023 at 11:40 PM Akihiko Odaki > > > > <akihiko.od...@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. > > Still Linux versions older than 2.6.35 do not look like "comparable software > versions to a listed platform" in my opinion.
This is fine - I would be ok to replace support with an error message and failure. Not checking that a capability is supported however isn't a good idea. And once we do - do we still gain anything by not working around that? > > And is something similar to such removal that has been done for other > > subsystems? > > With commit c42e77a90d ("qemu/osdep: Remove fallback for > MAP_FIXED_NOREPLACE"), I remove the support for glibc older than 2.28. Linux > 2.6.35 is even older.