Re: [PATCH v3 2/8] KVM: VMX: Refactor intel_pmu_set_msr() to align with other set_msr() helpers

Sean Christopherson
2023-01-27T02:09:37Z

On Fri, Nov 11, 2022, Like Xu wrote:
> From: Sean Christopherson <seanjc@google.com>
>
> Invert the flows in intel_pmu_set_msr()'s case statements so that they
> follow the kernel's preferred style of:
>
> if (<not valid>)
> return <error>
>
> <commit change>
> return <success>
>
> which is also the style used by every other set_msr() helper (except
> AMD's PMU variant, which doesn't use a switch statement).
>
> Opportunstically move the "val == current" checks below the validity
> checks. Except for the one-off case for MSR_P6_EVNTSEL2, the reserved
> bit checks are extremely cheap, and the guest is unlikely to frequently
> write the current value, i.e. avoiding the reserved bit checks doesn't
> add much (any?) value.
>
> No functional change intended.
>
> Signed-off-by: Sean Christopherson <seanjc@google.com>

FYI, I'm going to post this separately and extend it to give the get_msr() flow
the same treatment. I'll plan on getting it queued sooner than later so that
this series can use it as a base.