1 files changed, 12 insertions, 1 deletions
diff --git a/src/cpu/kvm/perfevent.cc b/src/cpu/kvm/perfevent.cc
index 5023b301e..0b5960d51 100644
--- a/src/cpu/kvm/perfevent.cc
+++ b/src/cpu/kvm/perfevent.cc
@@ -169,7 +169,18 @@ PerfKvmCounter::attach(PerfKvmCounterConfig &config,
                  group_fd,
                  0); // Flags
     if (fd == -1)
-        panic("PerfKvmCounter::open failed (%i)\n", errno);
+    {
+        if (errno == EACCES)
+        {
+            panic("PerfKvmCounter::attach recieved error EACCESS\n"
+            "  This error may be caused by a too restrictive setting\n"
+            "  in the file '/proc/sys/kernel/perf_event_paranoid'\n"
+            "  The default value was changed to 2 in kernel 4.6\n"
+            "  A value greater than 1 prevents gem5 from making\n"
+            "  the syscall to perf_event_open");
+        }
+        panic("PerfKvmCounter::attach failed (%i)\n", errno);
+    }
 
     mmapPerf(1);
 }