From 44e5d21e6d3fd2a1fed7f0327cf72e99397e2eaf Mon Sep 17 00:00:00 2001 From: Gautam Menghani Date: Fri, 8 Nov 2024 15:18:37 +0530 Subject: powerpc/pseries: Fix KVM guest detection for disabling hardlockup detector 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 Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241108094839.33084-1-gautam@linux.ibm.com --- arch/powerpc/kernel/setup_64.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch') 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(); } -- cgit