Re: [Qemu-devel] [PATCH 01/15] configure: add the disable-tcg option

[Paolo Bonzini]

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.

Paolo