Daniel P. Berrangé <[email protected]> writes:
> On Wed, Jun 27, 2018 at 09:57:09AM +0200, Markus Armbruster wrote: >> Thomas Huth <[email protected]> writes: >> >> > On 27.06.2018 08:51, Gerd Hoffmann wrote: >> [...] >> >> Drop support for 32bit hosts in qemu? >> > >> > I guess the only way to answer that question reliably is to send a patch >> > to mark 32-bit hosts as deprecated... >> > >> > Anyway, you still have got to fix that problem with -m32 now somehow >> > since we certainly can not drop 32-bit immediately. >> >> We certainly can if we want to. >> >> Our formal deprecation policy codifies our compromise between the need >> to evolve QEMU and the need of its users for stable external interfaces. >> >> "Compiles on host X" is also a need, but it's a different one. >> Evidence: "Supported build platforms" has its own appendix, separate >> from "Deprecated features". It's mum on 32-bit hosts. > > It is silent on host architecture coverage in general in fact. It was > only really focusing on operating systems and so any arch coverage is > at best inferred from what those OS target. Fedora covers 32-bit & 64-bit > arches for example, so you could take that to imply we need to support > both in QEMU. > > It is fuzzier though because while Peter has good OS coverage for his > merge testing, I don't think he has full host arch coverage for everything > that downstreams expect QEMU to build on ? We do however have cross build infrastructure for all tcg/foo backends. They are run by the shippable CI framework (which is how I noticed): https://app.shippable.com/github/qemu/qemu/runs?branchName=master Once we have the changes made to the wiki I'd like to use: https://wiki.qemu.org/Template:CIStatus In a few choice places on the wiki, including the front page, for better visibility. >> I'm not saying we *should* drop 32-bit hosts immediately. Only that the >> feature deprecation policy does not apply. >> >> Is QEMU still useful on 32-bit hosts? Honest question! > > That answer varies depending on what you're using QEMU for I think. It > could be that people see tools like qemu-img/qemu-nbd as useful even > if they don't use system emulators. And of course userspace emulators > are enough distinct use case. > > IMHO as long as distros are shipping 32-bit support, it is reasonable > to assume there will be people who find QEMU useful to some degree. > > Personally I don't have any need for 32-bit hosts, but clearly some > people do since otherwise distros would have killed their 32-bit > arches already. I know of at least one kernel developer who uses qemu-system-aarch64 on their 32 bit ARM Chromebook to test their 64 bit code. Next time I see them I'll see if they are still using it. My feeling is although probably not widespread it certainly can be handy. > > Regards, > Daniel -- Alex Bennée
