perf: 'perf kvm' tool for monitoring guest performance from host

Here is the patch of userspace perf tool.

Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 3a1d94d75dce..207e860591e2 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -33,7 +33,7 @@ static int perf_session__add_hist_entry(struct perf_session *self,
                 return -ENOMEM;
 
         if (hit)
-                he->count += count;
+                __perf_session__add_count(he, al, count);
 
         return 0;
 }
@@ -225,6 +225,10 @@ int cmd_diff(int argc, const char **argv, const char *prefix __used)
                         input_new = argv[1];
                 } else
                         input_new = argv[0];
+        } else if (symbol_conf.default_guest_vmlinux_name ||
+                   symbol_conf.default_guest_kallsyms) {
+                input_old = "perf.data.host";
+                input_new = "perf.data.guest";
         }
 
         symbol_conf.exclude_other = false;