linux_dsm_epyc7002/arch/x86
Thomas Gleixner d49597fd3b x86/cpu: Deal with broken firmware (VMWare/XEN)
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. The
physical package id which is used after a CPU comes up is retrieved from
CPUID. So we rely on ACPI/MP tables and CPUID agreeing in that respect.

There exist VMware and XEN implementations which violate the spec. As a
result the physical to logical package map, which relies on the ACPI/MP
tables does not work on those systems, because the CPUID initialized
physical package id does not match the firmware id. This causes system
crashes and malfunction due to invalid package mappings.

The only way to cure this is to sanitize the physical package id after the
CPUID enumeration and yell when the APIC ids are different. Fix up the
initial APIC id, which is fine as it is only used printout purposes.

If the physical package IDs differ yell and use the package information
from the ACPI/MP tables so the existing logical package map just works.

Chas provided the resulting dmesg output for his affected 4 virtual
sockets, 1 core per socket VM:

[Firmware Bug]: CPU1: APIC id mismatch. Firmware: 1 CPUID: 2
[Firmware Bug]: CPU1: Using firmware package id 1 instead of 2
....

Reported-and-tested-by: "Charles (Chas) Williams" <ciwillia@brocade.com>,
Reported-by: M. Vefa Bicakci <m.v.b@runbox.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: #4.6+ <stable@vger,kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1611091613540.3501@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-09 21:05:01 +01:00
..
boot * Refactor the EFI memory map code into architecture neutral files 2016-09-13 20:21:55 +02:00
configs IOMMU Updates for Linux v4.9 2016-10-11 12:52:41 -07:00
crypto crypto: sha512-mb - fix ctx pointer 2016-08-16 17:09:43 +08:00
entry x86/build: Fix build with older GCC versions 2016-10-25 11:44:25 +02:00
events perf/x86/intel: Honour the CPUID for number of fixed counters in hypervisors 2016-10-28 11:06:25 +02:00
ia32 x86/signal: Add SA_{X32,IA32}_ABI sa_flags 2016-09-14 21:28:11 +02:00
include x86/platform/intel-mid: Retrofit pci_platform_pm_ops ->get_state hook 2016-11-07 13:06:59 +01:00
kernel x86/cpu: Deal with broken firmware (VMWare/XEN) 2016-11-09 21:05:01 +01:00
kvm kvm: x86: Check memopp before dereference (CVE-2016-8630) 2016-11-02 21:31:53 +01:00
lguest lguest: Read offset of device_cap later 2016-06-10 11:39:09 +02:00
lib Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
math-emu
mm patches to fix a regression in 4.9-rc1 on x86 PAT 2016-10-28 09:36:07 -07:00
net bpf, x86: add support for constant blinding 2016-05-16 13:49:32 -04:00
oprofile oprofile/x86: Convert x86_backtrace() to use the new unwinder 2016-09-20 08:29:34 +02:00
pci PCI changes for the v4.9 merge window: 2016-10-07 11:46:37 -07:00
platform x86/platform/intel-mid: Retrofit pci_platform_pm_ops ->get_state hook 2016-11-07 13:06:59 +01:00
power x86/asm: Get rid of __read_cr4_safe() 2016-09-30 12:40:12 +02:00
purgatory Add sancov plugin 2016-06-07 22:57:10 +02:00
ras x86/RAS/mce_amd_inj: Remove debugfs dir recursively on exit 2016-09-26 11:13:17 +02:00
realmode x86/boot: Rework reserve_real_mode() to allow multiple tries 2016-08-11 11:15:01 +02:00
tools x86/insn: Add AVX-512 support to the instruction decoder 2016-07-21 09:37:11 -03:00
um Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
video x86/video: Don't assume all FB devices are PCI devices 2016-03-15 11:08:26 +01:00
xen xen: fixes for 4.9-rc2 2016-10-24 19:52:24 -07:00
.gitignore
Kbuild perf/x86: Move perf_event.c ............... => x86/events/core.c 2016-02-09 10:23:49 +01:00
Kconfig atomic64: no need for CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 2016-10-07 18:46:30 -07:00
Kconfig.cpu
Kconfig.debug Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-03-15 09:32:27 -07:00
Makefile lib/raid6: Add AVX512 optimized gen_syndrome functions 2016-09-21 09:09:44 -07:00
Makefile_32.cpu
Makefile.um