linux/arch
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
..
alpha Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
arc ARC: module: print pretty section names 2016-10-28 10:10:29 -07:00
arm Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm 2016-10-31 08:10:38 -07:00
arm64 ARM: SoC fixes 2016-10-29 12:07:29 -07:00
avr32 Merge branch 'akpm' (patches from Andrew) 2016-10-07 21:38:00 -07:00
blackfin Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
c6x nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
cris cris/arch-v32: cryptocop: print a hex number after a 0x prefix 2016-10-27 18:43:43 -07:00
frv Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
h8300 h8300: fix syscall restarting 2016-10-27 18:43:42 -07:00
hexagon nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
ia64 Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
m32r mm: replace access_process_vm() write parameter with gup_flags 2016-10-19 08:31:25 -07:00
m68k Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
metag Metag architecture fixes for v4.9-rc1 2016-10-14 11:11:39 -07:00
microblaze Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
mips One NULL pointer dereference, and two fixes for regressions introduced 2016-11-04 13:08:05 -07:00
mn10300 Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
nios2 nios2 update for v4.9-rc1 2016-10-10 11:31:19 -07:00
openrisc Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
parisc parisc: Ignore the pkey system calls for now 2016-11-02 23:07:14 +01:00
powerpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-29 20:33:20 -07:00
s390 One NULL pointer dereference, and two fixes for regressions introduced 2016-11-04 13:08:05 -07:00
score Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
sh Minor changes to improve J2 support and match Kconfig expectations of 2016-10-19 11:21:06 -07:00
sparc sparc64: Handle extremely large kernel TLB range flushes more gracefully. 2016-10-27 09:11:05 -07:00
tile tile: use simpler API for random address requests 2016-10-11 15:06:32 -07:00
um nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
unicore32 unicore32: use simpler API for random address requests 2016-10-11 15:06:32 -07:00
x86 x86/cpu: Deal with broken firmware (VMWare/XEN) 2016-11-09 21:05:01 +01:00
xtensa Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
.gitignore
Kconfig This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00