On 28/01/2025 01.42, Richard Henderson wrote:
Time for our biennial attempt to kill ancient hosts.
I've been re-working the tcg code generator a bit over the holidays.
One place that screams for a bit of cleanup is with 64-bit guest
addresses on 32-bit hosts. Of course the best "cleanup" is to not
have to handle such silliness at all.
Two years after Thomas' last attempt,
https://lore.kernel.org/qemu-devel/20230130114428.1297295-1-th...@redhat.com/
which resulted only in deprecation of i686 host for system emulation.
By itself, this just isn't enough for large-scale cleanups.
I'll note that we've separately deprecated mips32, set to expire
with the end of Debian bookworm, set to enter LTS in June 2026.
I'll note that there is *already* no Debian support for ppc32,
and that I am currently unable to cross-compile that host at all.
IIRC the biggest pushback that I got two years ago was with regards to
32-bit arm: The recommended version of Raspberry Pi OS is still 32-bit:
https://lore.kernel.org/qemu-devel/f852c238-77b8-4e24-9494-8d060eb78...@livius.net/
And looking at https://www.raspberrypi.com/software/operating-systems/ this
still seems to be the case...
So I guess the main question is now: Would it be ok to kill support for
32-bit Raspberry Pi OS nowadays?
Showing my hand a bit, I am willing to limit deprecation to
64-bit guests on 32-bit hosts. But I'd prefer to go the whole hog:
unconditional support for TCG_TYPE_I64 would remove a *lot* of
32-bit fallback code.
Sound like a good alternative to me!
Thomas
