Re: [RFC 2/9] target/arm: parse cpu feature related options

[Peng Liang]

On 8/13/2020 8:21 PM, Andrew Jones wrote:
> On Thu, Aug 13, 2020 at 06:26:50PM +0800, Peng Liang wrote:
>> The implementation of CPUClass::parse_features only supports CPU
>> features in "feature=value" format.  However, libvirt maybe send us a
>> CPU feature string in "+feature/-feature" format. 
> 
> Why would libvirt do that? If we have a boolean feature, then I'd think
> libvirt should be capable of sending feature=on/off just as easily as a
> +/-feature. Indeed libvirt seems to do the right thing with all the
> CPU features we already have: pmu, sve*, ...
> 
> Thanks,
> drew
> 
> .
> 

Libvirt before d47db7b16dd5422c7e487c8c8ee5b181a2f9cd66 ("qemu: command:
Support new cpu feature argument syntax") will send +/-feature.  Does QEMU
need to support it?  If not, I'll remote it.

Thanks,
Peng