From: Andi Kleen Date: Sun, 22 Jul 2007 09:12:39 +0000 (+0200) Subject: i386: Handle P6s without performance counters in nmi watchdog X-Git-Tag: v2.6.23-rc1~25 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=57c22f49e4c7d27a03e109a317c30b12f1bae0b2;p=linux-2.6 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 --- diff --git a/arch/i386/kernel/cpu/perfctr-watchdog.c b/arch/i386/kernel/cpu/perfctr-watchdog.c index 30b5e48aa7..572900398d 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