[RFC PATCH v3 1/2] vhost: Add callback and private data for vhost PMD

[Tetsuya Mukawa <mukawa@igel.co.jp>]

These variables are needed to be able to manage one of virtio devices
using both vhost library APIs and vhost PMD.
For example, if vhost PMD uses current callback handler and private data
provided by vhost library, A DPDK application that links vhost library
cannot use some of vhost library APIs. To avoid it, callback and private
data for vhost PMD are needed.

Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
---
 lib/librte_vhost/rte_virtio_net.h             |  3 ++
 lib/librte_vhost/vhost_user/virtio-net-user.c |  8 +++---
 lib/librte_vhost/virtio-net.c                 | 40 +++++++++++++++++++++++++--
 lib/librte_vhost/virtio-net.h                 |  3 +-
 4 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index 93d3e27..ec84c9b 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -108,6 +108,7 @@ struct virtio_net {
 	uint32_t		virt_qp_nb;
 	uint32_t		mem_idx;	/** Used in set memory layout, unique for each queue within virtio device. */
 	void			*priv;		/**< private context */
+	void			*pmd_priv;	/**< private context for vhost PMD */
 } __rte_cache_aligned;
 
 /**
@@ -198,6 +199,8 @@ int rte_vhost_driver_unregister(const char *dev_name);
 
 /* Register callbacks. */
 int rte_vhost_driver_callback_register(struct virtio_net_device_ops const * const);
+/* Register callbacks for vhost PMD (Only for internal). */
+int rte_vhost_driver_pmd_callback_register(struct virtio_net_device_ops const * const);
 /* Start vhost driver session blocking loop. */
 int rte_vhost_driver_session_start(void);
 
diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c b/lib/librte_vhost/vhost_user/virtio-net-user.c
index 6a12d96..a75697f 100644
--- a/lib/librte_vhost/vhost_user/virtio-net-user.c
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
@@ -288,7 +288,7 @@ user_set_vring_kick(struct vhost_device_ctx ctx, struct VhostUserMsg *pmsg)
 
 	if (virtio_is_ready(dev) &&
 		!(dev->flags & VIRTIO_DEV_RUNNING))
-			notify_ops->new_device(dev);
+			notify_new_device(dev);
 }
 
 /*
@@ -302,7 +302,7 @@ user_get_vring_base(struct vhost_device_ctx ctx,
 
 	/* We have to stop the queue (virtio) if it is running. */
 	if (dev->flags & VIRTIO_DEV_RUNNING)
-		notify_ops->destroy_device(dev);
+		notify_destroy_device(dev);
 
 	/* Here we are safe to get the last used index */
 	ops->get_vring_base(ctx, state->index, state);
@@ -333,7 +333,7 @@ user_reset_owner(struct vhost_device_ctx ctx,
 
 	/* We have to stop the queue (virtio) if it is running. */
 	if (dev->flags & VIRTIO_DEV_RUNNING)
-		notify_ops->destroy_device(dev);
+		notify_destroy_device(dev);
 
 	RTE_LOG(INFO, VHOST_CONFIG,
 		"reset owner --- state idx:%d state num:%d\n", state->index, state->num);
@@ -379,7 +379,7 @@ user_destroy_device(struct vhost_device_ctx ctx)
 	uint32_t i;
 
 	if (dev && (dev->flags & VIRTIO_DEV_RUNNING))
-		notify_ops->destroy_device(dev);
+		notify_destroy_device(dev);
 
 	for (i = 0; i < dev->virt_qp_nb; i++)
 		if (dev && dev->mem_arr[i]) {
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 3131719..eec3c22 100644
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -64,6 +64,8 @@ struct virtio_net_config_ll {
 
 /* device ops to add/remove device to/from data core. */
 struct virtio_net_device_ops const *notify_ops;
+/* device ops for vhost PMD to add/remove device to/from data core. */
+struct virtio_net_device_ops const *pmd_notify_ops;
 /* root address of the linked list of managed virtio devices */
 static struct virtio_net_config_ll *ll_root;
 
@@ -84,6 +86,29 @@ static uint64_t VHOST_FEATURES = VHOST_SUPPORTED_FEATURES;
 
 static uint64_t VHOST_PROTOCOL_FEATURES = VHOST_SUPPORTED_PROTOCOL_FEATURES;
 
+int
+notify_new_device(struct virtio_net *dev)
+{
+	if ((pmd_notify_ops != NULL) && (pmd_notify_ops->new_device != NULL)) {
+		int ret = pmd_notify_ops->new_device(dev);
+		if (ret != 0)
+			return ret;
+	}
+	if ((notify_ops != NULL) && (notify_ops->new_device != NULL))
+		return notify_ops->new_device(dev);
+
+	return 0;
+}
+
+void
+notify_destroy_device(volatile struct virtio_net *dev)
+{
+	if ((pmd_notify_ops != NULL) && (pmd_notify_ops->destroy_device != NULL))
+		pmd_notify_ops->destroy_device(dev);
+	if ((notify_ops != NULL) && (notify_ops->destroy_device != NULL))
+		notify_ops->destroy_device(dev);
+}
+
 /*
  * Converts QEMU virtual address to Vhost virtual address. This function is
  * used to convert the ring addresses to our address space.
@@ -421,7 +446,7 @@ destroy_device(struct vhost_device_ctx ctx)
 			 * the function to remove it from the data core.
 			 */
 			if ((ll_dev_cur->dev.flags & VIRTIO_DEV_RUNNING))
-				notify_ops->destroy_device(&(ll_dev_cur->dev));
+				notify_destroy_device(&(ll_dev_cur->dev));
 			ll_dev_cur = rm_config_ll_entry(ll_dev_cur,
 					ll_dev_last);
 		} else {
@@ -884,7 +909,7 @@ set_backend(struct vhost_device_ctx ctx, struct vhost_vring_file *file)
 				dev->virtqueue[VIRTIO_RXQ]->enabled = 1;
 				dev->virtqueue[VIRTIO_TXQ]->enabled = 1;
 			}
-			return notify_ops->new_device(dev);
+			return notify_new_device(dev);
 		}
 	/* Otherwise we remove it. */
 	} else
@@ -1006,3 +1031,14 @@ rte_vhost_driver_callback_register(struct virtio_net_device_ops const * const op
 
 	return 0;
 }
+
+/*
+ * Register ops so that we can add/remove device to data core.
+ */
+int
+rte_vhost_driver_pmd_callback_register(struct virtio_net_device_ops const * const ops)
+{
+	pmd_notify_ops = ops;
+
+	return 0;
+}
diff --git a/lib/librte_vhost/virtio-net.h b/lib/librte_vhost/virtio-net.h
index ef6efae..f92ed73 100644
--- a/lib/librte_vhost/virtio-net.h
+++ b/lib/librte_vhost/virtio-net.h
@@ -39,7 +39,8 @@
 
 #define VHOST_USER_PROTOCOL_F_VRING_FLAG 2
 
-struct virtio_net_device_ops const *notify_ops;
 struct virtio_net *get_device(struct vhost_device_ctx ctx);
 
+int notify_new_device(struct virtio_net *dev);
+void notify_destroy_device(volatile struct virtio_net *dev);
 #endif
-- 
2.1.4