diff -r 3de4393f5649 -r 3d08ce800ba0 SConstruct
--- a/SConstruct	Tue Oct 15 13:26:34 2013 +0200
+++ b/SConstruct	Tue Oct 15 13:44:55 2013 +0200
@@ -792,12 +792,35 @@
     context.Result(ret)
     return ret
 
+# Add a custom Check function to test for structure members.
+def CheckMember(context, include, decl, member, include_quotes="<>"):
+    context.Message("Checking for member %s in %s..." %
+                    (member, decl))
+    text = """
+#include %(header)s
+int main(){
+  %(decl)s test;
+  (void)test.%(member)s;
+  return 0;
+};
+""" % { "header" : include_quotes[0] + include + include_quotes[1],
+        "decl" : decl,
+        "member" : member,
+        }
+
+    ret = context.TryCompile(text, extension=".cc")
+    context.Result(ret)
+    return ret
+
 # Platform-specific configuration.  Note again that we assume that all
 # builds under a given build root run on the same host platform.
 conf = Configure(main,
                  conf_dir = joinpath(build_root, '.scons_config'),
                  log_file = joinpath(build_root, 'scons_config.log'),
-                 custom_tests = { 'CheckLeading' : CheckLeading })
+                 custom_tests = {
+        'CheckLeading' : CheckLeading,
+        'CheckMember' : CheckMember,
+        })
 
 # Check for leading underscores.  Don't really need to worry either
 # way so don't need to check the return code.
@@ -962,6 +985,12 @@
     return host_isa in isa_comp_table.get(isa, [])
 
 
+# Check if the exclude_host attribute is available. We want this to
+# get accurate instruction counts in KVM.
+main['HAVE_PERF_ATTR_EXCLUDE_HOST'] = conf.CheckMember(
+    'linux/perf_event.h', 'struct perf_event_attr', 'exclude_host')
+
+
 ######################################################################
 #
 # Finish the configuration
@@ -1063,7 +1092,8 @@
 
 # These variables get exported to #defines in config/*.hh (see src/SConscript).
 export_vars += ['USE_FENV', 'SS_COMPATIBLE_FP', 'TARGET_ISA', 'CP_ANNOTATE',
-                'USE_POSIX_CLOCK', 'PROTOCOL', 'HAVE_PROTOBUF']
+                'USE_POSIX_CLOCK', 'PROTOCOL', 'HAVE_PROTOBUF',
+                'HAVE_PERF_ATTR_EXCLUDE_HOST']
 
 ###################################################
 #
@@ -1241,6 +1271,13 @@
                 "target ISA combination"
             env['USE_KVM'] = False
 
+    # Warn about missing optional functionality
+    if env['USE_KVM']:
+        if not main['HAVE_PERF_ATTR_EXCLUDE_HOST']:
+            print "Warning: perf_event headers lack support for the " \
+                "exclude_host attribute. KVM instruction counts will " \
+                "be inaccurate."
+
     # Save sticky variable settings back to current variables file
     sticky_vars.Save(current_vars_file, env)
 
diff -r 3de4393f5649 -r 3d08ce800ba0 src/cpu/kvm/base.cc
--- a/src/cpu/kvm/base.cc	Tue Oct 15 13:26:34 2013 +0200
+++ b/src/cpu/kvm/base.cc	Tue Oct 15 13:44:55 2013 +0200
@@ -1133,6 +1133,12 @@
     cfgCycles.disabled(true)
         .pinned(true);
 
+    // Try to exclude the host. We set both exclude_hv and
+    // exclude_host since different architectures use slightly
+    // different APIs in the kernel.
+    cfgCycles.exclude_hv(true)
+        .exclude_host(true);
+
     if (perfControlledByTimer) {
         // We need to configure the cycles counter to send overflows
         // since we are going to use it to trigger timer signals that
@@ -1206,6 +1212,12 @@
     PerfKvmCounterConfig cfgInstructions(PERF_TYPE_HARDWARE,
                                          PERF_COUNT_HW_INSTRUCTIONS);
 
+    // Try to exclude the host. We set both exclude_hv and
+    // exclude_host since different architectures use slightly
+    // different APIs in the kernel.
+    cfgInstructions.exclude_hv(true)
+        .exclude_host(true);
+
     if (period) {
         // Setup a sampling counter if that has been requested.
         cfgInstructions.wakeupEvents(1)
diff -r 3de4393f5649 -r 3d08ce800ba0 src/cpu/kvm/perfevent.hh
--- a/src/cpu/kvm/perfevent.hh	Tue Oct 15 13:26:34 2013 +0200
+++ b/src/cpu/kvm/perfevent.hh	Tue Oct 15 13:44:55 2013 +0200
@@ -45,6 +45,8 @@
 
 #include <inttypes.h>
 
+#include "config/have_perf_attr_exclude_host.hh"
+
 /**
  * PerfEvent counter configuration.
  */
@@ -125,6 +127,39 @@
         return *this;
     }
 
+    /**
+     * Exclude the events from the host (i.e., only include events
+     * from the guest system).
+     *
+     * Intel CPUs seem to support this attribute from Linux 3.2 and
+     * onwards. Non-x86 architectures currently ignore this attribute
+     * (Linux 3.12-rc5).
+     *
+     * @warn This attribute is ignored if it isn't present in the
+     * kernel headers or if the kernel doesn't support it.
+     *
+     * @param val true to exclude host events
+     */
+    PerfKvmCounterConfig &exclude_host(bool val) {
+#if HAVE_PERF_ATTR_EXCLUDE_HOST == 1
+        attr.exclude_host = val;
+#endif
+        return *this;
+    }
+
+    /**
+     * Exclude the hyper visor (i.e., only include events from the
+     * guest system).
+     *
+     * @warn This is attribute only seems to be ignored on Intel.
+     *
+     * @param val true to exclude host events
+     */
+    PerfKvmCounterConfig &exclude_hv(bool val) {
+        attr.exclude_hv = val;
+        return *this;
+    }
+
     /** Underlying perf_event_attr structure describing the counter */
     struct perf_event_attr attr;
 };