Re: [Qemu-devel] [Patch v1 25/29] qmp: add QMP interface "query-cpu-model-comparison"

[Eduardo Habkost]

On Thu, Aug 04, 2016 at 09:34:16AM +0200, David Hildenbrand wrote:
> ##                                                                            
>   
> # @CpuModelCompareResult:                                                     
>   
> #                                                                             
>   
> # An enumeration of CPU model comparation results. The result is usually      
>   
> # calcualted using e.g. at CPU features or CPU generations.                   
>   
> #                                                                             
>   
> # @incompatible: If model A is incompatible to model B, model A is not        
>   
> #                guaranteed to run where model B runs and the other way 
> around. 
> #                                                                             
>   
> # @identical: If model A is identical to model B, model A is guaranteed to 
> run  
> #             where model B runs and the other way around.                    
>   
> #                                                                             
>   
> # @superset: If model A is a superset of model B, model B is guaranteed to 
> run  
> #            where model A runs. There are no guarantees about the other way. 
>   
> #                                                                             
>   
> # @subset: If model A is a subset of model B, model A is guaranteed to run    
>   
> #          where model B runs. There are no guarantees about the other way.   
>   
> #                                                                             
>   
> # Since: 2.8.0                                                                
>   
> ##
> 
> Think it's all about guarantees.
> 
[...]
> This comment is now:
> 
> ##                                                                            
>   
> # @query-cpu-model-comparison:                                                
>   
> #                                                                             
>   
> # Compares two CPU models, returning how they compare in a specific           
>   
> # configuration. The results indicates how both models compare regarding      
>   
> # runnability. This result can be used by tooling to make decisions if a      
>   
> # certain CPU model will run in a certain configuration or if a compatible    
>   
> # CPU model has to be created by baselining.                                  
>   
> #                                                                             
>   
> # Usually, a CPU model is compared against the maximum possible CPU model     
>   
> # of a ceratin configuration (e.g. the "host" model for KVM). If that CPU     
>   
> # model is identical or a subset, it will run in that configuration.          
>   
> #                                                                             
>   
> # The result returned by this command may be affected by:                     
>   
> #                                                                             
>   
> # * QEMU version: CPU models may look different depending on the QEMU 
> version.  
> #   (Except for CPU models reported as "static" in query-cpu-definitions.)    
>   
> # * machine-type: CPU model  may look different depending on the 
> machine-type.  
> #   (Except for CPU models reported as "static" in query-cpu-definitions.)    
>   
> # * machine options (including accelerator): in some architectures, CPU 
> models  
> #   may look different depending on machine and accelerator options. (Except 
> for
> #   CPU models reported as "static" in query-cpu-definitions.)                
>   
> # * "-cpu" arguments and global properties: arguments to the -cpu option and  
>   
> #   global properties may affect expansion of CPU models. Using               
>   
> #   query-cpu-model-expansion while using these is not advised.               
>   
> #                                                                             
>   
> # Some architectures may not support comparing CPU models. s390x supports     
>   
> # comparing CPU models.                                                       
>   
> #                                                                             
>   
> # Returns: a CpuModelBaselineInfo. Returns an error if comparing CPU models 
> is  
> #          not supported, if a model cannot be used, if a model contains      
>   
> #          an unknown cpu definition name, unknown properties or properties   
>   
> #          with wrong types.                                                  
>   
> #                                                                             
>   
> # Since: 2.8.0                                                                
>   
> ##  
> 
> (excluding the remark about s390x in this patch)

Both look very clear to me. Thanks!

-- 
Eduardo