vcl: support for eventfd mq signaling

- support eventfd based mq signaling. Based on configuration, vcl
epoll/select can use either condvars or epoll on mq eventfds.
- add vcl support for memfd segments
- vpp explicitly registers cut-through segments with apps/vcl
- if using eventfd, make ldp allow one call to libc_epoll_create. Needed
for the message queue epfd
- update svm_queue_t to allow blocking calls with eventfd signaling.

Change-Id: I064151ac370bbe29bb16c968bf4e3659c8286bea
Signed-off-by: Florin Coras <fcoras@cisco.com>

1 files changed, 32 insertions, 2 deletions

diff --git a/src/vnet/session/session.api b/src/vnet/session/session.api
index 98748d8fbbb..58054ae4ba2 100644
--- a/src/vnet/session/session.api
+++ b/src/vnet/session/session.api
@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
-option version = "1.0.3";
+option version = "1.1.0";
 
 /** \brief client->vpp, attach application to session layer
     @param client_index - opaque cookie to identify the sender
@@ -38,6 +38,9 @@ option version = "1.0.3";
     @param retval - return code for the request
     @param app_event_queue_address - vpp event queue address or 0 if this 
                                  	 connection shouldn't send events
+    @param n_fds - number of fds exchanged
+    @param fd_flags - set of flags that indicate which fds are to be expected
+    				  over the socket (set only if socket transport available) 
     @param segment_size - size of first shm segment
     @param segment_name_length - length of segment name 
     @param segment_name - name of segment client needs to attach to
@@ -46,6 +49,8 @@ define application_attach_reply {
     u32 context;
     i32 retval;
     u64 app_event_queue_address;
+    u8 n_fds;
+    u8 fd_flags;
     u32 segment_size;
     u8 segment_name_length;
     u8 segment_name[128];
@@ -91,11 +96,16 @@ autoreply define application_detach {
 /** \brief vpp->client, please map an additional shared memory segment
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
-    @param segment_name - 
+   	@param fd_flags - set of flags that indicate which, if any, fds are 
+   					  to be expected over the socket. This is set only if 
+   					  socket transport available
+    @param segment_size - size of the segment to be mapped
+    @param segment_name - name of the segment to be mapped
 */
 autoreply define map_another_segment {
     u32 client_index;
     u32 context;
+    u8 fd_flags;
     u32 segment_size;
     u8 segment_name[128];
 };
@@ -391,6 +401,26 @@ define connect_session_reply {
   u16 lcl_port;
 };
 
+/** \brief ask app to add a new cut-through registration
+    @param client_index - opaque cookie to identify the sender
+                          client to vpp direction only
+    @param context - sender context, to match reply w/ request
+    @param evt_q_address - address of the mq in ssvm segment
+    @param peer_evt_q_address - address of peer's mq in ssvm segment
+    @param n_fds - number of fds exchanged
+    @param fd_flags - flag indicating the fds that will be exchanged over
+    				  api socket
+*/
+autoreply define app_cut_through_registration_add
+{
+  u32 client_index;
+  u32 context;
+  u64 evt_q_address;
+  u64 peer_evt_q_address;
+  u8 n_fds;
+  u8 fd_flags;
+};
+
 /** \brief enable/disable session layer
     @param client_index - opaque cookie to identify the sender
                           client to vpp direction only