On 24/07/2017 16:11, Daniel P. Berrange wrote: >>> + >>> +The supported lifetime for versioned machine types is 12 releases, >>> +which is equivalent to 4 years worth of previous QEMU releases. >> I think there's still no consensus on this. > > Indeed, which is exactly why I sent this patch - we need to come up > with a sensible policy here, so we can stop repeating the same debate > over & over & over each time some proposes a patch to kill off some > random old machine type. > > The 12 release / 4 year figure was a fairly arbitrary starting > point to which I'd be hoping to see critical reviewer feedback > on (with possible counterproposals) so we can try to get something > documented, to put an end to the repeated debates in this area > each time someone proposes a patch.
I agree. At the moment, the status is "machine types never die". We can change it, but I think that we should also make a decision on whether removing machine types implies removing properties that only exist for backwards-compatibility reasons. 4 year seems like a long time, but it can actually be pretty taxing for RHEL. I'm pretty sure that around RHEL 8.4 (some time between 2020-2022) we'll need a 1.5-ish machine type (2016). Paolo >> The first two paragraphs >> should be added to the documentation for -machine in qemu-options.hx, >> since "-machine [type=]foo" is currently not documented at all. > I'll happily send a patch for the docs for qemu-options.hx.
