[dpdk-dev] [PATCH v5 2/9] net/virtio: add in-order feature bit definition

[Marvin Liu <yong.liu@intel.com>]

If VIRTIO_F_IN_ORDER has been negotiated, driver will use descriptors in
ring order: starting from offset 0 in the table, and wrapping around at
the end of the table. Also introduce use_inorder_[rt]x flag for
selection of IN_ORDER [RT]x handlers.

Signed-off-by: Marvin Liu <yong.liu@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
index a28ba8339..77f805df6 100644
--- a/drivers/net/virtio/virtio_pci.h
+++ b/drivers/net/virtio/virtio_pci.h
@@ -121,6 +121,12 @@ struct virtnet_ctl;
 #define VIRTIO_TRANSPORT_F_START 28
 #define VIRTIO_TRANSPORT_F_END   34
 
+/*
+ * Inorder feature indicates that all buffers are used by the device
+ * in the same order in which they have been made available.
+ */
+#define VIRTIO_F_IN_ORDER 35
+
 /* The Guest publishes the used index for which it expects an interrupt
  * at the end of the avail ring. Host should ignore the avail->flags field. */
 /* The Host publishes the avail index for which it expects a kick
@@ -233,6 +239,8 @@ struct virtio_hw {
 	uint8_t     modern;
 	uint8_t     use_simple_rx;
 	uint8_t     use_simple_tx;
+	uint8_t     use_inorder_rx;
+	uint8_t     use_inorder_tx;
 	uint16_t    port_id;
 	uint8_t     mac_addr[ETHER_ADDR_LEN];
 	uint32_t    notify_off_multiplier;
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 1c102ca72..8747cbf94 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -441,6 +441,8 @@ virtio_user_eth_dev_alloc(struct rte_vdev_device *vdev)
 	hw->modern   = 0;
 	hw->use_simple_rx = 0;
 	hw->use_simple_tx = 0;
+	hw->use_inorder_rx = 0;
+	hw->use_inorder_tx = 0;
 	hw->virtio_user_dev = dev;
 	return eth_dev;
 }
-- 
2.17.0