On Wed, Nov 09, 2016 at 04:35:51PM +0100, Thomas Gleixner wrote: > Both ACPI and MP specifications require that the APIC id in the respective > tables must be the same as the APIC id in CPUID. > > The kernel retrieves the physical package id from the APIC id during the > ACPI/MP table scan and builds the physical to logical package map. > > There exist Virtualbox and Xen implementations which violate the spec. As a
ISTR it was VMware, not VirtualBox, but whatever.. they're both crazy virt stuff. > /* > + * The physical to logical package id mapping is initialized from the > + * acpi/mptables information. Make sure that CPUID actually agrees with > + * that. > + */ > +static void sanitize_package_id(struct cpuinfo_x86 *c) > +{ > +#ifdef CONFIG_SMP > + unsigned int pkg, apicid, cpu = smp_processor_id(); > + > + apicid = apic->cpu_present_to_apicid(cpu); > + pkg = apicid >> boot_cpu_data.x86_coreid_bits; > + > + if (apicid != c->initial_apicid) { > + pr_err(FW_BUG "CPU%u: APIC id mismatch. Firmware: %x CPUID: > %x\n", > + cpu, apicid, c->initial_apicid); Should we not also 'fix' c->initial_apicid ? > + } > + if (pkg != c->phys_proc_id) { > + pr_err(FW_BUG "CPU%u: Using firmware package id %u instead of > %u\n", > + cpu, pkg, c->phys_proc_id); > + c->phys_proc_id = pkg; > + } > + c->logical_proc_id = topology_phys_to_logical_pkg(pkg); > +#else > + c->locical_proc_id = 0; UP FTW ;-) > +#endif > +}