On 22/06/2017 11:30, Thomas Huth wrote: > 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.
Yes, I agree. Thanks for reviewing the patch. Paolo
