Messages in this thread | | | From | "Liang, Kan" <> | Subject | RE: [PATCH V4 1/2] perf ignore LBR and extra_regs. | Date | Wed, 9 Jul 2014 14:32:28 +0000 |
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> On Tue, Jul 08, 2014 at 09:49:40AM -0700, kan.liang@intel.com wrote: > > +/* > > + * Under certain circumstances, access certain MSR may cause #GP. > > + * The function tests if the input MSR can be safely accessed. > > + */ > > +static inline bool check_msr(unsigned long msr) { > > + u64 value; > > + > > + if (rdmsrl_safe(msr, &value) < 0) > > + return false; > > + if (wrmsrl_safe(msr, value) < 0) > > + return false; > > + return true; > > +} > > What does this thing return after patch 2? does the write still fault or will > KVM silently take writes too?
If applying patch 2, the function will return true. The KVM just simply ignore the reads/writes.
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