On 2019/3/23 0:52, Peter Zijlstra wrote: > On Fri, Mar 22, 2019 at 05:44:45PM +0100, Borislav Petkov wrote: >> On Sat, Mar 23, 2019 at 12:19:01AM +0800, Pu Wen wrote: >>> That 6 is not a magic number. >> >> Well, if I see a naked 6, then it is only magic to me. Now if it were a >> proper define with a descriptive name... > > Does AMD/Hygon not have a CPUID leaf to read useful things like this > from?
ApicId[6] is read from CPUID_Fn00000001_EBX[30]. Please see section 2.1.11.1 and 2.1.10.2.1.3 of referrence [1]. Reference: [1] https://www.amd.com/system/files/TechDocs/54945_PPR_Family_17h_Models_00h-0Fh.pdf -- Regards, Pu Wen
