29.06.2018 23:24, Bernard wrote: [] >> I can say even more: upstream is seriously thinking about dropping 32bit >> host support completely, not only on x86 but on other architectures too, >> because supporting 32bit mode, especially to run 64bit guests, is not >> easy at all. So don't be surprized if one day it wont work at all, >> by definition (not by incident like now) > > You mean the kvm acceleration part is not easy with 64bit guests on > 32bits hosts? I expect the pure emulation part of qemu to be still > maintained, it's its core idea and useful for testing new > architectures/configurations.
Nope, it is worse. No qemu developers run any 32bit system at all. This qemu-system-i386 works when it is a 64bit x86 application. But it fails for you when it is a 32bit application. But no developer even _tries_ to run a 32bit qemu application, not to say about maintaining anything. That's why qemu team is considering dropping 32bi host support completely. No one actually maintains it, and even keeping 32bit qemu executables to be _compilable_ requires quite some effort, sometimes non-trivial (recent story was about 64bit atomic counters which does not exist in 32bit app since even 64bit increment is implemented in multiple instructions on 32bit) [] > But looking at the current i386 rank vs. the amd64 one on the > Popularity Contest web page, I realize now I should not have been > surprised. 32bit code with today hardware comes with lots of pitfails. Especially the memory management in the kernel which should be able to use all system memory which is often >4Gb (absolute limit for 32bit addressing). All current smartphones comes with 4+Gb RAM so have to run 64bit code. There are many other limitations, for example 32bit x86 has less available registers in the CPU than 64bit code. And I suspect that even in-CPU 32bit compatibility support is bit-rotting these days - expect more recent CPUs to break old 32bit applications.. >> So, in short, please don't hold your breath waiting till this will be fixed. >> Instead, try to switch to 64bit, -- that will be the real fix. > > So I understand that you want to move the bug in the "won't fix" category. > Fair enough. I don't "want" it to move, really. I'm saying something slightly different. You're running bitrotting configuration. Even if this particular BIG issue will be fixed, you risk to hit other issues, and it's good if it will just crash or refuse to start, - worse if it result in some data loss... Thanks! /mjt
