vhost: Add event index for interrupt notification to driver

VPP only supports a poor man's approach for interrupt notification to the
driver. It uses a simple binary flag for "interrupt needed" or "interrupt
not needed". Most drivers support more sophisticated event index already.
This feature is to add the long due missing feature and make it configurable,
off by default.

Type: feature

Signed-off-by: Steven Luong <sluong@cisco.com>
Change-Id: I68dab7dd07045cafb49af97b7f70db9b8131ae03

1 files changed, 7 insertions, 6 deletions

diff --git a/src/vnet/devices/virtio/vhost_user_output.c b/src/vnet/devices/virtio/vhost_user_output.c
index 80eefa6d9ed..465c0ea0903 100644
--- a/src/vnet/devices/virtio/vhost_user_output.c
+++ b/src/vnet/devices/virtio/vhost_user_output.c
@@ -279,7 +279,8 @@ vhost_user_handle_tx_offload (vhost_user_intf_t * vui, vlib_buffer_t * b,
 }
 
 static_always_inline void
-vhost_user_mark_desc_available (vlib_main_t * vm, vhost_user_vring_t * rxvq,
+vhost_user_mark_desc_available (vlib_main_t * vm, vhost_user_intf_t * vui,
+				vhost_user_vring_t * rxvq,
 				u16 * n_descs_processed, u8 chained,
 				vlib_frame_t * frame, u32 n_left)
 {
@@ -334,7 +335,7 @@ vhost_user_mark_desc_available (vlib_main_t * vm, vhost_user_vring_t * rxvq,
 
       rxvq->n_since_last_int += frame->n_vectors - n_left;
       if (rxvq->n_since_last_int > vum->coalesce_frames)
-	vhost_user_send_call (vm, rxvq);
+	vhost_user_send_call (vm, vui, rxvq);
     }
 }
 
@@ -645,7 +646,7 @@ retry:
 	  copy_len = 0;
 
 	  /* give buffers back to driver */
-	  vhost_user_mark_desc_available (vm, rxvq, &n_descs_processed,
+	  vhost_user_mark_desc_available (vm, vui, rxvq, &n_descs_processed,
 					  chained, frame, n_left);
 	}
 
@@ -660,8 +661,8 @@ done:
 	vlib_error_count (vm, node->node_index,
 			  VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
 
-      vhost_user_mark_desc_available (vm, rxvq, &n_descs_processed, chained,
-				      frame, n_left);
+      vhost_user_mark_desc_available (vm, vui, rxvq, &n_descs_processed,
+				      chained, frame, n_left);
     }
 
   /*
@@ -1019,7 +1020,7 @@ done:
       rxvq->n_since_last_int += frame->n_vectors - n_left;
 
       if (rxvq->n_since_last_int > vum->coalesce_frames)
-	vhost_user_send_call (vm, rxvq);
+	vhost_user_send_call (vm, vui, rxvq);
     }
 
   vhost_user_vring_unlock (vui, qid);