RE: [PATCH 4/4] target/i386: add live migration support for FRED

[Li, Xin3]

> > FRED CPU states are managed in 10 FRED MSRs, in addtion to a few
> > existing CPU registers and MSRs, e.g., the CR4.FRED bit.
> >
> > Add the 10 new FRED MSRs to x86 CPUArchState for live migration support.
> >
> 
> IMO, it's better to split this patch into two, one is for FRED MSR access, 
> the other
> is for LM support.
> 
> And move the FRED MSRs from basic x86_cpu part to .subsections part because
> FRED doesn't belong to basic CPU registers.  In the .subsections part, you may
> define a struct to hold FRED MSRs then add  .needed callback helper for QEMU 
> to
> query whether FRED MSRs are necessary for live migration.

Good point!

> 
> See other features, e.g., vmstate_msr_intel_sgx