On 25/06/20 18:25, Sean Christopherson wrote: > I get the "what" of the change, and even the "why" to some extent, but I > dislike the idea of supporting/encouraging blind reads/writes to MSRs. > Blind writes are just asking for problems, and suppressing warnings on reads > is almost guaranteed to be suppressing a KVM bug. Right, that's why this patch does not just suppress warnings: it adds a different return value to detect the case. > TSC_CTRL aside, if we insist on pointing a gun at our foot at some point, > this should be a dedicated flavor of MSR access, e.g. msr_data.kvm_initiated, > so that it at least requires intentionally loading the gun. With this patch, __kvm_get_msr does not know about ignore_msrs at all, that seems to be strictly an improvement; do you agree with that? What would you think about adding warn_unused_result to __kvm_get_msr? Paolo