linux/arch
Michael Kelley f1f8288d19 x86/hyperv: Disable hardlockup detector by default in Hyper-V guests
In newer versions of Hyper-V, the x86/x64 PMU can be virtualized
into guest VMs by explicitly enabling it. Linux kernels are typically
built to automatically enable the hardlockup detector if the PMU is
found. To prevent the possibility of false positives due to the
vagaries of VM scheduling, disable the PMU-based hardlockup detector
by default in a VM on Hyper-V.  The hardlockup detector can still be
enabled by overriding the default with the nmi_watchdog=1 option on
the kernel boot line or via sysctl at runtime.

This change mimics the approach taken with KVM guests in
commit 692297d8f9 ("watchdog: introduce the hardlockup_detector_disable()
function").

Linux on ARM64 does not provide a PMU-based hardlockup detector, so
there's no corresponding disable in the Hyper-V init code on ARM64.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1652111063-6535-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2022-05-11 14:36:46 +00:00
..
alpha Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
arc ARC: remove redundant READ_ONCE() in cmpxchg loop 2022-04-18 14:47:05 -07:00
arm xen: branch for v5.18-rc4 2022-04-23 13:53:21 -07:00
arm64 arm64 fixes for -rc4 2022-04-22 13:49:26 -07:00
csky ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
h8300 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
hexagon ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
ia64 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
m68k Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
microblaze Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
mips - build fix for gpio 2022-04-02 12:14:38 -07:00
nios2 ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
openrisc ptrace: Cleanups for v5.18 2022-03-28 17:29:53 -07:00
parisc Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
powerpc powerpc fixes for 5.18 #3 2022-04-24 12:11:20 -07:00
riscv RISC-V: 2022-04-22 17:58:36 -07:00
s390 RISC-V: 2022-04-22 17:58:36 -07:00
sh Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2022-04-01 19:57:03 -07:00
sparc sparc: cacheflush_32.h needs struct page 2022-04-23 09:27:17 -07:00
um Kbuild fixes for v5.18 2022-04-02 12:33:31 -07:00
x86 x86/hyperv: Disable hardlockup detector by default in Hyper-V guests 2022-05-11 14:36:46 +00:00
xtensa xtensa: fix a7 clobbering in coprocessor context load/store 2022-04-15 18:44:02 -07:00
.gitignore
Kconfig vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLOW_HUGE_VMAP 2022-04-19 12:08:57 -07:00