Re: [PATCH v10 00/28] KVM: Enable FRED support with KVM VMX

[Xin Li]

> On Sep 11, 2026, at 2:36 PM, Sohil Mehta <sohil.mehta@xxxxxxxxx> wrote:
> 
> I mainly rebased the patches to the latest kvm-x86/next branch and fixed
> a handful of issues reported during internal testing and basic AI
> reviews. I've avoided making any major code changes or commit message
> updates as this is the first iteration that I am posting. 

Thanks a lot for taking care of the patch series.

> 
> Going forward, based on the feedback, I'll rework the patches as needed.
> I've listed a few opens below that need additional discussion or
> clarification. I'm relatively new to the KVM subsystem, so please feel
> free to provide suggestions on the series structure, code organization
> as well as commit log clarity to smoothen the review process.

I’ve been thinking about an optimization: because FRED drops most of the old    
syscall MSRs (IA32_LSTAR/IA32_CSTAR/IA32_SFMASK), we should be able to omit     
them from KVM's uret MSR tracking entirely as if host enables FRED (no matter   
whether a guest uses FRED).

Thanks!
Xin