Re: [Qemu-arm] [PATCH 06/10] target-i386: print obsolete warnings if +-features are used

[Paolo Bonzini]

On 07/06/2016 14:32, Igor Mammedov wrote:
>> > Could you detect using +foo together with foo=off, and -foo together
>> > with foo=on?  Those are the really problematic cases, without them +foo
>> > and -foo can become synonyms for =on and =off.
> That's (legacy)current semantic of -cpu +-foo where it overrides any foo=x,
> potentially it's possible to track foo=x locally in parser
> and then compare with +-foo both ways.
> But all we can do currently is to print warning about such use case.
> 
> I think Eduardo's suggestion to just warn that +-foo is obsolete for now
> and drop support for it in several releases is sufficient(good) enough.

kvm-unit-tests and libvirt both use it, especially because =on and =off
are relatively new I think?  It seems like it's really widespread.

Paolo