Re: [PATCH 0/2] i386: Adjust CPUID_EXT_PDCM based on enable_pmu at realization

[Zhao Liu <zhao1.liu@intel.com>]

Hi Xiaoyao,

> First, it's not a good practice that values in env->features[] cannot be
> directly used for guest CPUID in void cpu_x86_cpuid(), but require further
> adjustment there. env->features[] are supposed to be finalized at cpu
> realization, so that after it env->features[] is reliable.
> 
> Second, there is one dependency entry relates to CPUID_EXT_PDCM in
> feature_dependencies[]. QEMU needs to get correct value of
> CPUID_EXT_PDCM in env->features[] to ensure applying the dependencies
> correctly.

I agree that this is a very good idea, especially since PDCM has a
dependency entry.

"pmu" is totally a property rather than a feature bit, which makes the
dependency relationships in the code complex. Therefore, I think it's
worth having a series to clarify the dependencies of pmu as much as
possible.

I remember Dapeng/Zide also have fixes for pmu dependencies, and if
possible, I could help you combine this series with others' cleanups.

Additionally, I think patch 1 and patch 2 can be merged together. Do you
agree?

Thanks,
Zhao