On Wed, 17 Apr 2019, Fenghua Yu wrote: > On Thu, Apr 18, 2019 at 12:14:12AM +0200, Thomas Gleixner wrote: > > On Wed, 17 Apr 2019, Fenghua Yu wrote: > > > +DEFINE_PER_CPU(u64, msr_test_ctl_cache); > > > +EXPORT_PER_CPU_SYMBOL_GPL(msr_test_ctl_cache); > > > > Contrary to things like cpufeatures or MSR bits, it's pretty useless to > > have a separate patch for this. Please fold this into the place which > > actualy uses it. > > Can I fold this patch into the KVM patch 0013 which first uses (reads) the > variable? But the variable will be set in later patches when enabling split > lock feature (patch 0014) and when enabling/disabling split lock feature > (patch 0015). > > Is this a right sequence to fit the variable in the patch set? As I said in the other reply, you are assuming that the content of that MSR is 0. Which might be true now, but is that true in a year from now? So you really want to at least initialize the variable by reading the MSR _before_ you make use of it in KVM. Thanks, tglx