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| author | Gautam Menghani <gautam@linux.ibm.com> | 2024-11-08 15:18:37 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-12-05 14:02:43 +0100 |
| commit | 58d6473042e8ef117ad0d339bd782ed6854d3bf1 (patch) | |
| tree | 14c34e439917a0df28ca68ec6c5cc758636409ee /arch | |
| parent | 952741d54de920cac316998dda298c2bcc4b65d1 (diff) | |
| download | linux-58d6473042e8ef117ad0d339bd782ed6854d3bf1.tar.gz linux-58d6473042e8ef117ad0d339bd782ed6854d3bf1.tar.bz2 linux-58d6473042e8ef117ad0d339bd782ed6854d3bf1.zip | |
powerpc/pseries: Fix KVM guest detection for disabling hardlockup detector
commit 44e5d21e6d3fd2a1fed7f0327cf72e99397e2eaf upstream.
As per the kernel documentation[1], hardlockup detector should
be disabled in KVM guests as it may give false positives. On
PPC, hardlockup detector is enabled inside KVM guests because
disable_hardlockup_detector() is marked as early_initcall and it
relies on kvm_guest static key (is_kvm_guest()) which is initialized
later during boot by check_kvm_guest(), which is a core_initcall.
check_kvm_guest() is also called in pSeries_smp_probe(), which is called
before initcalls, but it is skipped if KVM guest does not have doorbell
support or if the guest is launched with SMT=1.
Call check_kvm_guest() in disable_hardlockup_detector() so that
is_kvm_guest() check goes through fine and hardlockup detector can be
disabled inside the KVM guest.
[1]: Documentation/admin-guide/sysctl/kernel.rst
Fixes: 633c8e9800f3 ("powerpc/pseries: Enable hardlockup watchdog for PowerVM partitions")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Gautam Menghani <gautam@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241108094839.33084-1-gautam@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 22f83fbbc762..1edc7cd68c10 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -920,6 +920,7 @@ static int __init disable_hardlockup_detector(void) hardlockup_detector_disable(); #else if (firmware_has_feature(FW_FEATURE_LPAR)) { + check_kvm_guest(); if (is_kvm_guest()) hardlockup_detector_disable(); } |