Re: [PATCH v4 10/19] x86/cpu: Detect VMX features on Intel, Centaur and Zhaoxin CPUs

On Thu, Dec 12, 2019 at 09:55:11AM -0800, Sean Christopherson wrote:

The reasoning behind using vanilla rdmsr() on PROC and PIN controls is that those MSRs should exist on any CPU that supports VMX, i.e. we want the WARN.

The alternative would be to use rdmsr_safe() for everything and then explicitly disable VMX if a fault on PROC or PIN occurs, but that circles us back to the handling a fault on rdmsr(MSR_IA32_FEAT_CTL), i.e. is it really worth gracefully handling a fault that should never occur?

No but pls put a comment above it explaining why we're doing rdmsr() only with those two MSRs.

Thx.