vhost: potential crash in map_guest_mem using debug image

map_guest_mem may be called from worker-thread/dataplane. It has a call
to vlib_log and may crash inside vlib_log's ASSERT statement

  /* make sure we are running on the main thread to avoid use in dataplane
     code, for dataplane logging consider use of event-logger */
  ASSERT (vlib_get_thread_index () == 0);

The fix is to convert the vlib_log call in map_guest_map to event logger

Change-Id: Iaaf6d86782aa8a18d25e0209f22dc31f04668d56
Signed-off-by: Steven Luong <sluong@cisco.com>
(cherry picked from commit b0789106cb4f4c7ac529c02a5ff1ac346f0913dd)

1 files changed, 14 insertions, 1 deletions

diff --git a/src/vnet/devices/virtio/vhost_user_inline.h b/src/vnet/devices/virtio/vhost_user_inline.h
index 02c15ad666f..544e2d36952 100644
--- a/src/vnet/devices/virtio/vhost_user_inline.h
+++ b/src/vnet/devices/virtio/vhost_user_inline.h
@@ -15,6 +15,7 @@
 #ifndef __VIRTIO_VHOST_USER_INLINE_H__
 #define __VIRTIO_VHOST_USER_INLINE_H__
 /* vhost-user inline functions */
+#include <vppinfra/elog.h>
 
 static_always_inline void *
 map_guest_mem (vhost_user_intf_t * vui, uword addr, u32 * hint)
@@ -134,7 +135,19 @@ vhost_map_guest_mem_done:
 	}
     }
 #endif
-  vu_log_err (vui, "failed to map guest mem addr %llx", addr);
+  /* *INDENT-OFF* */
+  ELOG_TYPE_DECLARE (el) =
+  {
+    .format = "failed to map guest mem addr %lx",
+    .format_args = "i8",
+  };
+  /* *INDENT-ON* */
+  struct
+  {
+    uword addr;
+  } *ed;
+  ed = ELOG_DATA (&vlib_global_main.elog_main, el);
+  ed->addr = addr;
   *hint = 0;
   return 0;
 }