CVS commit: src/sys/arch/x86/x86

[Christos Zoulas]

Module Name:    src
Committed By:   christos
Date:           Wed Jun 26 20:52:28 UTC 2013

Modified Files:
        src/sys/arch/x86/x86: identcpu.c

Log Message:
PR/47967: Jeff Rizzo: Add a probe for QEMU to disable it from claiming it
has MSR_TSC. Fixes DTRACE crashing because it returned a frequency of 0.


To generate a diff of this commit:
cvs rdiff -u -r1.32 -r1.33 src/sys/arch/x86/x86/identcpu.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/arch/x86/x86/identcpu.c
diff -u src/sys/arch/x86/x86/identcpu.c:1.32 src/sys/arch/x86/x86/identcpu.c:1.33
--- src/sys/arch/x86/x86/identcpu.c:1.32	Sat Jun 16 13:30:19 2012
+++ src/sys/arch/x86/x86/identcpu.c	Wed Jun 26 16:52:28 2013
@@ -1,4 +1,4 @@
-/*	$NetBSD: identcpu.c,v 1.32 2012/06/16 17:30:19 chs Exp $	*/
+/*	$NetBSD: identcpu.c,v 1.33 2013/06/26 20:52:28 christos Exp $	*/
 
 /*-
  * Copyright (c) 1999, 2000, 2001, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: identcpu.c,v 1.32 2012/06/16 17:30:19 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: identcpu.c,v 1.33 2013/06/26 20:52:28 christos Exp $");
 
 #include "opt_xen.h"
 
@@ -563,6 +563,17 @@ cpu_probe_geode(struct cpu_info *ci)
 }
 
 static void
+cpu_probe_qemu(struct cpu_info *ci)
+{
+       if (memcmp("QEMU Virtual CPU", cpu_brand_string, 16) != 0)
+               return;
+
+       /* if QEMU does not implement MSR_TSC, disable the TSC */
+       ci->ci_feat_val[0] &= ~CPUID_MSR;
+       cpu_feature[0] &= ~CPUID_MSR;
+}
+
+static void
 cpu_probe_vortex86(struct cpu_info *ci)
 {
 #define PCI_MODE1_ADDRESS_REG	0x0cf8
@@ -709,6 +720,7 @@ cpu_probe(struct cpu_info *ci)
 	cpu_probe_c3(ci);
 	cpu_probe_geode(ci);
 	cpu_probe_vortex86(ci);
+	cpu_probe_qemu(ci);
 
 	x86_cpu_topology(ci);