Commit 57c22f49 authored Jul 22, 2007 by Andi Kleen Committed by Linus Torvalds Jul 22, 2007

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 <avi@qumranet.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent f25f64ed

arch/i386/kernel/cpu/perfctr-watchdog.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -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