On 22.06.2017 11:26, Paolo Bonzini wrote: > > > On 22/06/2017 08:33, Thomas Huth wrote: >> On 22.06.2017 08:22, Paolo Bonzini wrote: >>> >>>> On 21.06.2017 12:19, Yang Zhong wrote: >>>>> Add the disable-tcg option into configure and echo CONFIG_TCG=y into >>>>> $config_target_mak. The default tcg is enabled for all build. If tcg >>>>> is disabled in the build, only i386|x86_64 softmmu option can be disabled, >>>>> other softmmu of tagets and users build defaultly enabled the tcg. >>>> Why do you want to limit this disablement to x86 only? There are also >>>> other architectures that support KVM (ARM, PPC, MIPS), so disabling TCG >>>> might be possible there, too. So I think it might be better to check >>>> whether KVM is possible instead. >>> >>> You need to be careful and not use any helper from e.g. KVM or migration >>> code. So I would be very surprised if any other architecture compiles >>> with --disable-tcg. >> >> OK, fair, but we finally might want to get there, so I think we should >> allow the parameter in the configure script for other architectures, >> too, and then fix the bugs once we can try it out. > > I think it's the other way round---when someone wants to fix it, they > should add their architecture to the list of targets that support > --disable-tcg. "./configure <anything>", as a goal, should fail > immediately if make won't succeed; compilation errors are always a worse > experience.
Fine for me, too, but then the configure script should exit with a proper error message when the user tried to specify --disable-tcg on a non-x86 architecture. If I get the current patch right, it silently falls back to CONFIG_TCG=y instead, which is IMHO also a bad experience. Thomas
