Date: Thu, 28 Apr 2016 08:29:57 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r298736 - head/sys/amd64/amd64 Message-ID: <201604280829.u3S8Tvwl045202@repo.freebsd.org>
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Author: avg Date: Thu Apr 28 08:29:57 2016 New Revision: 298736 URL: https://svnweb.freebsd.org/changeset/base/298736 Log: ensure that initial local apic id is sane on AMD 10h systems Summary: The Initial Local APIC ID is returned by CPUID function 1 (in EBX). On AMD Family 10h systems the way that ID is built is controlled by an MSR bit (InitApicIdCpuIdLo). BKDG instructs BIOS to set it in a certain way, but a BIOS can be buggy. In that case the ID can confuse tools that use it, e.g. hwloc. For example, on a system that I own real Local APIC IDs are configured as 0, 1, 2, 3, but IDs reported via CPUID.1 are 0, 0x40, 0x80, 0xc0. See: https://github.com/open-mpi/hwloc/issues/183 Reviewed by: kib MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D6060 Modified: head/sys/amd64/amd64/initcpu.c Modified: head/sys/amd64/amd64/initcpu.c ============================================================================== --- head/sys/amd64/amd64/initcpu.c Thu Apr 28 06:20:43 2016 (r298735) +++ head/sys/amd64/amd64/initcpu.c Thu Apr 28 08:29:57 2016 (r298736) @@ -80,6 +80,19 @@ init_amd(void) wrmsr(0xc0011029, rdmsr(0xc0011029) | 1); break; } + + /* + * BIOS may fail to set InitApicIdCpuIdLo to 1 as it should per BKDG. + * So, do it here or otherwise some tools could be confused by + * Initial Local APIC ID reported with CPUID Function 1 in EBX. + */ + if (CPUID_TO_FAMILY(cpu_id) == 0x10) { + if ((cpu_feature2 & CPUID2_HV) == 0) { + msr = rdmsr(MSR_NB_CFG1); + msr |= (uint64_t)1 << 54; + wrmsr(MSR_NB_CFG1, msr); + } + } } /*
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