From 57c22f49e4c7d27a03e109a317c30b12f1bae0b2 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Sun, 22 Jul 2007 11:12:39 +0200 Subject: [PATCH] i386: Handle P6s without performance counters in nmi watchdog I got an oops while booting a 32bit kernel on KVM because it doesn't implement performance counters used by the NMI watchdog. Handle this case. Cc: Avi Kivity Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/i386/kernel/cpu/perfctr-watchdog.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/i386/kernel/cpu/perfctr-watchdog.c b/arch/i386/kernel/cpu/perfctr-watchdog.c index 30b5e48aa76b..572900398def 100644 --- a/arch/i386/kernel/cpu/perfctr-watchdog.c +++ b/arch/i386/kernel/cpu/perfctr-watchdog.c @@ -346,7 +346,9 @@ static int setup_p6_watchdog(unsigned nmi_hz) perfctr_msr = MSR_P6_PERFCTR0; evntsel_msr = MSR_P6_EVNTSEL0; - wrmsrl(perfctr_msr, 0UL); + /* KVM doesn't implement this MSR */ + if (wrmsr_safe(perfctr_msr, 0, 0) < 0) + return 0; evntsel = P6_EVNTSEL_INT | P6_EVNTSEL_OS -- 2.20.1