On Mon, 2020-09-07 at 12:06 +0200, Borislav Petkov wrote: > + Srinivas. > + kitsunyan. > > On Mon, Sep 07, 2020 at 11:48:43AM +0200, Jason A. Donenfeld wrote: > > Popular tools, like intel-undervolt, use MSR 0x150 to control the > > CPU > > voltage offset. In fact, evidently the intel_turbo_max_3 driver in- > > tree > > also uses this MSR. So, teach the kernel's MSR list about this, so > > that > > intel-undervolt and other such tools don't spew warnings to dmesg, > > while > > unifying the constant used throughout the kernel. > >
[...] > > - if (reg == MSR_IA32_ENERGY_PERF_BIAS) > > + switch (reg) { > > + case MSR_IA32_ENERGY_PERF_BIAS: There is already sysfs interface for it. > > + case MSR_IA32_OC_MAILBOX: > > return 0; > > + } > > [...] > Actually, we added the filtering to catch exactly such misuses and, > lemme check what is the proper word now... /me checks, aha, adding > new > MSRs to the "passlist" is the wrong thing to do. > > Srinivas, can you pls convert this in-tree driver to use a proper > sysfs > interface for that mailbox MSR and also work with the intel-undervolt > author - I hope I have the right person CCed from the git repo on > github > - to come up with a proper interface so that we can drop this MSR use > too. Overclocking is not architectural I/F and is supported by some special CPU skews. I can't find any public document to specify the commands which can be used via this OC mailbox. I have to check internally to see if there is any. To add a proper sysfs interface we have to make sure that we are not allowing some random commands to hardware and crash the system. Thanks, Srinivas