[PATCH v6 0/5] vhost: vhost_user.c code cleanup

[PATCH v6 0/5] vhost: vhost_user.c code cleanup

[Nikolay Nikolaev]

vhost: vhost_user.c code cleanup

This patchesries introduce a set of code redesigns in vhost_user.c.

The goal is to unify and simplify vhost-user message handling. The
patches do not intend to introduce any functional changes.

v6 changes:
 - Even more fixes to the usage of struct VhostUserMsg in
   the patches (Anatoly Burakov)

v5 changes:
 - fixed the usage of struct VhostUserMsg in all patches (Anatoly Burakov)

v4 changes:
 - use struct VhostUserMsg as the coding style guide suggests (Anatoly Burakov)
 - VH_RESULT_FATAL is removed as not needed anymore (Maxime Coquelin)

v3 changes:
 - rebased on top of git://dpdk.org/next/dpdk-next-virtio dead0602
 - introduce VH_RESULT_FATAL (Maxime Coquelin)
 - vhost_user_set_features return VH_RESULT_FATAL on failure.
   This allows keeping the propagate error logic (Ilya Maximets)
 - fixed vhost_user_set_vring_kick and vhost_user_set_protocol_features
   return VH_RESULT_ERR upon failure
 - fixed missing break in case VH_RESULT_ERR (Ilya Maximets)
 - fixed a type on the description of 2/5 patch (Maxime Coquelin)

v2 changes:
 - Fix the comments by Tiwei Bie
 - Keep the old behavior
   - Fall through when the callback returns VH_RESULT_ERR
   - Fall through if the request is out of range

---

Nikolay Nikolaev (5):
      vhost: unify struct VhostUserMsg usage
      vhost: make message handling functions prepare the reply
      vhost: handle unsupported message types in functions
      vhost: unify message handling function signature
      vhost: message handling implemented as a callback array


 lib/librte_vhost/vhost_user.c |  394 ++++++++++++++++++++++-------------------
 1 file changed, 209 insertions(+), 185 deletions(-)

--
Signature

[PATCH v6 1/5] vhost: unify struct VhostUserMsg usage

[Nikolay Nikolaev]

Do not use the typedef version of struct VhostUserMsg. Also unify the
related parameter name.

Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
---
 lib/librte_vhost/vhost_user.c |   41 +++++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 20 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 63d145b2d..505db3bfc 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -250,7 +250,7 @@ vhost_user_set_features(struct virtio_net *dev, uint64_t features)
  */
 static int
 vhost_user_set_vring_num(struct virtio_net *dev,
-			 VhostUserMsg *msg)
+			 struct VhostUserMsg *msg)
 {
 	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
 
@@ -611,7 +611,7 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
  * This function then converts these to our address space.
  */
 static int
-vhost_user_set_vring_addr(struct virtio_net **pdev, VhostUserMsg *msg)
+vhost_user_set_vring_addr(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
 	struct vhost_virtqueue *vq;
 	struct vhost_vring_addr *addr = &msg->payload.addr;
@@ -648,7 +648,7 @@ vhost_user_set_vring_addr(struct virtio_net **pdev, VhostUserMsg *msg)
  */
 static int
 vhost_user_set_vring_base(struct virtio_net *dev,
-			  VhostUserMsg *msg)
+			  struct VhostUserMsg *msg)
 {
 	dev->virtqueue[msg->payload.state.index]->last_used_idx  =
 			msg->payload.state.num;
@@ -780,10 +780,10 @@ vhost_memory_changed(struct VhostUserMemory *new,
 }
 
 static int
-vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *pmsg)
+vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
 	struct virtio_net *dev = *pdev;
-	struct VhostUserMemory memory = pmsg->payload.memory;
+	struct VhostUserMemory memory = msg->payload.memory;
 	struct rte_vhost_mem_region *reg;
 	void *mmap_addr;
 	uint64_t mmap_size;
@@ -804,7 +804,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *pmsg)
 			"(%d) memory regions not changed\n", dev->vid);
 
 		for (i = 0; i < memory.nregions; i++)
-			close(pmsg->fds[i]);
+			close(msg->fds[i]);
 
 		return 0;
 	}
@@ -845,7 +845,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *pmsg)
 	dev->mem->nregions = memory.nregions;
 
 	for (i = 0; i < memory.nregions; i++) {
-		fd  = pmsg->fds[i];
+		fd  = msg->fds[i];
 		reg = &dev->mem->regions[i];
 
 		reg->guest_phys_addr = memory.regions[i].guest_phys_addr;
@@ -994,16 +994,16 @@ virtio_is_ready(struct virtio_net *dev)
 }
 
 static void
-vhost_user_set_vring_call(struct virtio_net *dev, struct VhostUserMsg *pmsg)
+vhost_user_set_vring_call(struct virtio_net *dev, struct VhostUserMsg *msg)
 {
 	struct vhost_vring_file file;
 	struct vhost_virtqueue *vq;
 
-	file.index = pmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
-	if (pmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
+	file.index = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
+	if (msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
 		file.fd = VIRTIO_INVALID_EVENTFD;
 	else
-		file.fd = pmsg->fds[0];
+		file.fd = msg->fds[0];
 	RTE_LOG(INFO, VHOST_CONFIG,
 		"vring call idx:%d file:%d\n", file.index, file.fd);
 
@@ -1015,17 +1015,17 @@ vhost_user_set_vring_call(struct virtio_net *dev, struct VhostUserMsg *pmsg)
 }
 
 static int
-vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *pmsg)
+vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
 	struct vhost_vring_file file;
 	struct vhost_virtqueue *vq;
 	struct virtio_net *dev = *pdev;
 
-	file.index = pmsg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
-	if (pmsg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
+	file.index = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
+	if (msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
 		file.fd = VIRTIO_INVALID_EVENTFD;
 	else
-		file.fd = pmsg->fds[0];
+		file.fd = msg->fds[0];
 	RTE_LOG(INFO, VHOST_CONFIG,
 		"vring kick idx:%d file:%d\n", file.index, file.fd);
 
@@ -1073,7 +1073,7 @@ free_zmbufs(struct vhost_virtqueue *vq)
  */
 static int
 vhost_user_get_vring_base(struct virtio_net *dev,
-			  VhostUserMsg *msg)
+			  struct VhostUserMsg *msg)
 {
 	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
 
@@ -1126,7 +1126,7 @@ vhost_user_get_vring_base(struct virtio_net *dev,
  */
 static int
 vhost_user_set_vring_enable(struct virtio_net *dev,
-			    VhostUserMsg *msg)
+			    struct VhostUserMsg *msg)
 {
 	int enable = (int)msg->payload.state.num;
 	int index = (int)msg->payload.state.index;
@@ -1485,7 +1485,8 @@ send_vhost_slave_message(struct virtio_net *dev, struct VhostUserMsg *msg,
  * Allocate a queue pair if it hasn't been allocated yet
  */
 static int
-vhost_user_check_and_alloc_queue_pair(struct virtio_net *dev, VhostUserMsg *msg)
+vhost_user_check_and_alloc_queue_pair(struct virtio_net *dev,
+			struct VhostUserMsg *msg)
 {
 	uint16_t vring_idx;
 
@@ -1818,9 +1819,9 @@ vhost_user_msg_handler(int vid, int fd)
 }
 
 static int process_slave_message_reply(struct virtio_net *dev,
-				       const VhostUserMsg *msg)
+				       const struct VhostUserMsg *msg)
 {
-	VhostUserMsg msg_reply;
+	struct VhostUserMsg msg_reply;
 	int ret;
 
 	if ((msg->flags & VHOST_USER_NEED_REPLY) == 0)

[PATCH v6 2/5] vhost: make message handling functions prepare the reply

[Nikolay Nikolaev]

As VhostUserMsg structure is reused to generate the reply, move the
relevant fields update into the respective message handling functions.

Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
---
 lib/librte_vhost/vhost_user.c |   24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 505db3bfc..4ae7b9346 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -146,11 +146,15 @@ vhost_user_reset_owner(struct virtio_net *dev)
  * The features that we support are requested.
  */
 static uint64_t
-vhost_user_get_features(struct virtio_net *dev)
+vhost_user_get_features(struct virtio_net *dev, struct VhostUserMsg *msg)
 {
 	uint64_t features = 0;
 
 	rte_vhost_driver_get_features(dev->ifname, &features);
+
+	msg->payload.u64 = features;
+	msg->size = sizeof(msg->payload.u64);
+
 	return features;
 }
 
@@ -158,11 +162,15 @@ vhost_user_get_features(struct virtio_net *dev)
  * The queue number that we support are requested.
  */
 static uint32_t
-vhost_user_get_queue_num(struct virtio_net *dev)
+vhost_user_get_queue_num(struct virtio_net *dev, struct VhostUserMsg *msg)
 {
 	uint32_t queue_num = 0;
 
 	rte_vhost_driver_get_queue_num(dev->ifname, &queue_num);
+
+	msg->payload.u64 = (uint64_t)queue_num;
+	msg->size = sizeof(msg->payload.u64);
+
 	return queue_num;
 }
 
@@ -1117,6 +1125,8 @@ vhost_user_get_vring_base(struct virtio_net *dev,
 	rte_free(vq->batch_copy_elems);
 	vq->batch_copy_elems = NULL;
 
+	msg->size = sizeof(msg->payload.state);
+
 	return 0;
 }
 
@@ -1244,6 +1254,8 @@ vhost_user_set_log_base(struct virtio_net *dev, struct VhostUserMsg *msg)
 	dev->log_base = dev->log_addr + off;
 	dev->log_size = size;
 
+	msg->size = sizeof(msg->payload.u64);
+
 	return 0;
 }
 
@@ -1658,8 +1670,7 @@ vhost_user_msg_handler(int vid, int fd)
 
 	switch (msg.request.master) {
 	case VHOST_USER_GET_FEATURES:
-		msg.payload.u64 = vhost_user_get_features(dev);
-		msg.size = sizeof(msg.payload.u64);
+		vhost_user_get_features(dev, &msg);
 		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_FEATURES:
@@ -1690,7 +1701,6 @@ vhost_user_msg_handler(int vid, int fd)
 		if (ret)
 			goto skip_to_reply;
 		/* it needs a reply */
-		msg.size = sizeof(msg.payload.u64);
 		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_LOG_FD:
@@ -1712,7 +1722,6 @@ vhost_user_msg_handler(int vid, int fd)
 		ret = vhost_user_get_vring_base(dev, &msg);
 		if (ret)
 			goto skip_to_reply;
-		msg.size = sizeof(msg.payload.state);
 		send_vhost_reply(fd, &msg);
 		break;
 
@@ -1730,8 +1739,7 @@ vhost_user_msg_handler(int vid, int fd)
 		break;
 
 	case VHOST_USER_GET_QUEUE_NUM:
-		msg.payload.u64 = (uint64_t)vhost_user_get_queue_num(dev);
-		msg.size = sizeof(msg.payload.u64);
+		vhost_user_get_queue_num(dev, &msg);
 		send_vhost_reply(fd, &msg);
 		break;
 

[PATCH v6 3/5] vhost: handle unsupported message types in functions

[Nikolay Nikolaev]

Add new functions to handle the unsupported vhost message types:
 - vhost_user_set_vring_err
 - vhost_user_set_log_fd

Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
---
 lib/librte_vhost/vhost_user.c |   22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 4ae7b9346..77905dda0 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1022,6 +1022,14 @@ vhost_user_set_vring_call(struct virtio_net *dev, struct VhostUserMsg *msg)
 	vq->callfd = file.fd;
 }
 
+static void vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
+			struct VhostUserMsg *msg)
+{
+	if (!(msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK))
+		close(msg->fds[0]);
+	RTE_LOG(INFO, VHOST_CONFIG, "not implemented\n");
+}
+
 static int
 vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
@@ -1259,6 +1267,13 @@ vhost_user_set_log_base(struct virtio_net *dev, struct VhostUserMsg *msg)
 	return 0;
 }
 
+static void vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
+			struct VhostUserMsg *msg)
+{
+	close(msg->fds[0]);
+	RTE_LOG(INFO, VHOST_CONFIG, "not implemented.\n");
+}
+
 /*
  * An rarp packet is constructed and broadcasted to notify switches about
  * the new location of the migrated VM, so that packets from outside will
@@ -1704,8 +1719,7 @@ vhost_user_msg_handler(int vid, int fd)
 		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_LOG_FD:
-		close(msg.fds[0]);
-		RTE_LOG(INFO, VHOST_CONFIG, "not implemented.\n");
+		vhost_user_set_log_fd(&dev, &msg);
 		break;
 
 	case VHOST_USER_SET_VRING_NUM:
@@ -1733,9 +1747,7 @@ vhost_user_msg_handler(int vid, int fd)
 		break;
 
 	case VHOST_USER_SET_VRING_ERR:
-		if (!(msg.payload.u64 & VHOST_USER_VRING_NOFD_MASK))
-			close(msg.fds[0]);
-		RTE_LOG(INFO, VHOST_CONFIG, "not implemented\n");
+		vhost_user_set_vring_err(&dev, &msg);
 		break;
 
 	case VHOST_USER_GET_QUEUE_NUM:

[PATCH v6 4/5] vhost: unify message handling function signature

[Nikolay Nikolaev]

Each vhost-user message handling function will return an int result
which is described in the new enum vh_result: error, OK and reply.
All functions will now have two arguments, virtio_net double pointer
and VhostUserMsg pointer.

Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
---
 lib/librte_vhost/vhost_user.c |  211 ++++++++++++++++++++++++-----------------
 1 file changed, 125 insertions(+), 86 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 77905dda0..e1b705fa7 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -71,6 +71,16 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
 	[VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
 };
 
+/* The possible results of a message handling function */
+enum vh_result {
+	/* Message handling failed */
+	VH_RESULT_ERR   = -1,
+	/* Message handling successful */
+	VH_RESULT_OK    =  0,
+	/* Message handling successful and reply prepared */
+	VH_RESULT_REPLY =  1,
+};
+
 static uint64_t
 get_blk_size(int fd)
 {
@@ -127,27 +137,31 @@ vhost_backend_cleanup(struct virtio_net *dev)
  * the device hasn't been initialised.
  */
 static int
-vhost_user_set_owner(void)
+vhost_user_set_owner(struct virtio_net **pdev __rte_unused,
+		struct VhostUserMsg *msg __rte_unused)
 {
-	return 0;
+	return VH_RESULT_OK;
 }
 
 static int
-vhost_user_reset_owner(struct virtio_net *dev)
+vhost_user_reset_owner(struct virtio_net **pdev,
+		struct VhostUserMsg *msg __rte_unused)
 {
+	struct virtio_net *dev = *pdev;
 	vhost_destroy_device_notify(dev);
 
 	cleanup_device(dev, 0);
 	reset_device(dev);
-	return 0;
+	return VH_RESULT_OK;
 }
 
 /*
  * The features that we support are requested.
  */
-static uint64_t
-vhost_user_get_features(struct virtio_net *dev, struct VhostUserMsg *msg)
+static int
+vhost_user_get_features(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	uint64_t features = 0;
 
 	rte_vhost_driver_get_features(dev->ifname, &features);
@@ -155,15 +169,16 @@ vhost_user_get_features(struct virtio_net *dev, struct VhostUserMsg *msg)
 	msg->payload.u64 = features;
 	msg->size = sizeof(msg->payload.u64);
 
-	return features;
+	return VH_RESULT_REPLY;
 }
 
 /*
  * The queue number that we support are requested.
  */
-static uint32_t
-vhost_user_get_queue_num(struct virtio_net *dev, struct VhostUserMsg *msg)
+static int
+vhost_user_get_queue_num(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	uint32_t queue_num = 0;
 
 	rte_vhost_driver_get_queue_num(dev->ifname, &queue_num);
@@ -171,15 +186,17 @@ vhost_user_get_queue_num(struct virtio_net *dev, struct VhostUserMsg *msg)
 	msg->payload.u64 = (uint64_t)queue_num;
 	msg->size = sizeof(msg->payload.u64);
 
-	return queue_num;
+	return VH_RESULT_REPLY;
 }
 
 /*
  * We receive the negotiated features supported by us and the virtio device.
  */
 static int
-vhost_user_set_features(struct virtio_net *dev, uint64_t features)
+vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
+	uint64_t features = msg->payload.u64;
 	uint64_t vhost_features = 0;
 	struct rte_vdpa_device *vdpa_dev;
 	int did = -1;
@@ -189,12 +206,12 @@ vhost_user_set_features(struct virtio_net *dev, uint64_t features)
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"(%d) received invalid negotiated features.\n",
 			dev->vid);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	if (dev->flags & VIRTIO_DEV_RUNNING) {
 		if (dev->features == features)
-			return 0;
+			return VH_RESULT_OK;
 
 		/*
 		 * Error out if master tries to change features while device is
@@ -205,7 +222,7 @@ vhost_user_set_features(struct virtio_net *dev, uint64_t features)
 			RTE_LOG(ERR, VHOST_CONFIG,
 				"(%d) features changed while device is running.\n",
 				dev->vid);
-			return -1;
+			return VH_RESULT_ERR;
 		}
 
 		if (dev->notify_ops->features_changed)
@@ -250,16 +267,17 @@ vhost_user_set_features(struct virtio_net *dev, uint64_t features)
 	if (vdpa_dev && vdpa_dev->ops->set_features)
 		vdpa_dev->ops->set_features(dev->vid);
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 /*
  * The virtio device sends us the size of the descriptor ring.
  */
 static int
-vhost_user_set_vring_num(struct virtio_net *dev,
+vhost_user_set_vring_num(struct virtio_net **pdev,
 			 struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
 
 	vq->size = msg->payload.state.num;
@@ -272,7 +290,7 @@ vhost_user_set_vring_num(struct virtio_net *dev,
 	if ((vq->size & (vq->size - 1)) || vq->size > 32768) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"invalid virtqueue size %u\n", vq->size);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	if (dev->dequeue_zero_copy) {
@@ -298,7 +316,7 @@ vhost_user_set_vring_num(struct virtio_net *dev,
 		if (!vq->shadow_used_packed) {
 			RTE_LOG(ERR, VHOST_CONFIG,
 					"failed to allocate memory for shadow used ring.\n");
-			return -1;
+			return VH_RESULT_ERR;
 		}
 
 	} else {
@@ -308,7 +326,7 @@ vhost_user_set_vring_num(struct virtio_net *dev,
 		if (!vq->shadow_used_split) {
 			RTE_LOG(ERR, VHOST_CONFIG,
 					"failed to allocate memory for shadow used ring.\n");
-			return -1;
+			return VH_RESULT_ERR;
 		}
 	}
 
@@ -318,10 +336,10 @@ vhost_user_set_vring_num(struct virtio_net *dev,
 	if (!vq->batch_copy_elems) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"failed to allocate memory for batching copy.\n");
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 /*
@@ -621,12 +639,12 @@ translate_ring_addresses(struct virtio_net *dev, int vq_index)
 static int
 vhost_user_set_vring_addr(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	struct vhost_virtqueue *vq;
 	struct vhost_vring_addr *addr = &msg->payload.addr;
-	struct virtio_net *dev = *pdev;
 
 	if (dev->mem == NULL)
-		return -1;
+		return VH_RESULT_ERR;
 
 	/* addr->index refers to the queue index. The txq 1, rxq is 0. */
 	vq = dev->virtqueue[msg->payload.addr.index];
@@ -643,27 +661,28 @@ vhost_user_set_vring_addr(struct virtio_net **pdev, struct VhostUserMsg *msg)
 				(1ULL << VHOST_USER_F_PROTOCOL_FEATURES))) {
 		dev = translate_ring_addresses(dev, msg->payload.addr.index);
 		if (!dev)
-			return -1;
+			return VH_RESULT_ERR;
 
 		*pdev = dev;
 	}
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 /*
  * The virtio device sends us the available ring last used index.
  */
 static int
-vhost_user_set_vring_base(struct virtio_net *dev,
+vhost_user_set_vring_base(struct virtio_net **pdev,
 			  struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	dev->virtqueue[msg->payload.state.index]->last_used_idx  =
 			msg->payload.state.num;
 	dev->virtqueue[msg->payload.state.index]->last_avail_idx =
 			msg->payload.state.num;
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 static int
@@ -804,7 +823,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
 	if (memory.nregions > VHOST_MEMORY_MAX_NREGIONS) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"too many memory regions (%u)\n", memory.nregions);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	if (dev->mem && !vhost_memory_changed(&memory, dev->mem)) {
@@ -814,7 +833,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
 		for (i = 0; i < memory.nregions; i++)
 			close(msg->fds[i]);
 
-		return 0;
+		return VH_RESULT_OK;
 	}
 
 	if (dev->mem) {
@@ -838,7 +857,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
 				"(%d) failed to allocate memory "
 				"for dev->guest_pages\n",
 				dev->vid);
-			return -1;
+			return VH_RESULT_ERR;
 		}
 	}
 
@@ -848,7 +867,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"(%d) failed to allocate memory for dev->mem\n",
 			dev->vid);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 	dev->mem->nregions = memory.nregions;
 
@@ -945,7 +964,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
 
 			dev = translate_ring_addresses(dev, i);
 			if (!dev)
-				return -1;
+				return VH_RESULT_ERR;
 
 			*pdev = dev;
 		}
@@ -953,13 +972,13 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
 
 	dump_guest_pages(dev);
 
-	return 0;
+	return VH_RESULT_OK;
 
 err_mmap:
 	free_mem_region(dev);
 	rte_free(dev->mem);
 	dev->mem = NULL;
-	return -1;
+	return VH_RESULT_ERR;
 }
 
 static bool
@@ -1001,9 +1020,10 @@ virtio_is_ready(struct virtio_net *dev)
 	return 1;
 }
 
-static void
-vhost_user_set_vring_call(struct virtio_net *dev, struct VhostUserMsg *msg)
+static int
+vhost_user_set_vring_call(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	struct vhost_vring_file file;
 	struct vhost_virtqueue *vq;
 
@@ -1020,22 +1040,26 @@ vhost_user_set_vring_call(struct virtio_net *dev, struct VhostUserMsg *msg)
 		close(vq->callfd);
 
 	vq->callfd = file.fd;
+
+	return VH_RESULT_OK;
 }
 
-static void vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
+static int vhost_user_set_vring_err(struct virtio_net **pdev __rte_unused,
 			struct VhostUserMsg *msg)
 {
 	if (!(msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK))
 		close(msg->fds[0]);
 	RTE_LOG(INFO, VHOST_CONFIG, "not implemented\n");
+
+	return VH_RESULT_OK;
 }
 
 static int
 vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	struct vhost_vring_file file;
 	struct vhost_virtqueue *vq;
-	struct virtio_net *dev = *pdev;
 
 	file.index = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
 	if (msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK)
@@ -1048,7 +1072,7 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg)
 	/* Interpret ring addresses only when ring is started. */
 	dev = translate_ring_addresses(dev, file.index);
 	if (!dev)
-		return -1;
+		return VH_RESULT_ERR;
 
 	*pdev = dev;
 
@@ -1065,7 +1089,8 @@ vhost_user_set_vring_kick(struct virtio_net **pdev, struct VhostUserMsg *msg)
 	if (vq->kickfd >= 0)
 		close(vq->kickfd);
 	vq->kickfd = file.fd;
-	return 0;
+
+	return VH_RESULT_OK;
 }
 
 static void
@@ -1088,9 +1113,10 @@ free_zmbufs(struct vhost_virtqueue *vq)
  * when virtio is stopped, qemu will send us the GET_VRING_BASE message.
  */
 static int
-vhost_user_get_vring_base(struct virtio_net *dev,
+vhost_user_get_vring_base(struct virtio_net **pdev,
 			  struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
 
 	/* We have to stop the queue (virtio) if it is running. */
@@ -1135,7 +1161,7 @@ vhost_user_get_vring_base(struct virtio_net *dev,
 
 	msg->size = sizeof(msg->payload.state);
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 /*
@@ -1143,9 +1169,10 @@ vhost_user_get_vring_base(struct virtio_net *dev,
  * enable the virtio queue pair.
  */
 static int
-vhost_user_set_vring_enable(struct virtio_net *dev,
+vhost_user_set_vring_enable(struct virtio_net **pdev,
 			    struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	int enable = (int)msg->payload.state.num;
 	int index = (int)msg->payload.state.index;
 	struct rte_vdpa_device *vdpa_dev;
@@ -1166,13 +1193,14 @@ vhost_user_set_vring_enable(struct virtio_net *dev,
 
 	dev->virtqueue[index]->enabled = enable;
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
-static void
-vhost_user_get_protocol_features(struct virtio_net *dev,
+static int
+vhost_user_get_protocol_features(struct virtio_net **pdev,
 				 struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	uint64_t features, protocol_features;
 
 	rte_vhost_driver_get_features(dev->ifname, &features);
@@ -1189,40 +1217,46 @@ vhost_user_get_protocol_features(struct virtio_net *dev,
 
 	msg->payload.u64 = protocol_features;
 	msg->size = sizeof(msg->payload.u64);
+
+	return VH_RESULT_OK;
 }
 
 static int
-vhost_user_set_protocol_features(struct virtio_net *dev,
-				 uint64_t protocol_features)
+vhost_user_set_protocol_features(struct virtio_net **pdev,
+				 struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
+	uint64_t protocol_features = msg->payload.u64;
 	if (protocol_features & ~VHOST_USER_PROTOCOL_FEATURES) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"(%d) received invalid protocol features.\n",
 			dev->vid);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	dev->protocol_features = protocol_features;
-	return 0;
+
+	return VH_RESULT_OK;
 }
 
 static int
-vhost_user_set_log_base(struct virtio_net *dev, struct VhostUserMsg *msg)
+vhost_user_set_log_base(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	int fd = msg->fds[0];
 	uint64_t size, off;
 	void *addr;
 
 	if (fd < 0) {
 		RTE_LOG(ERR, VHOST_CONFIG, "invalid log fd: %d\n", fd);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	if (msg->size != sizeof(VhostUserLog)) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"invalid log base msg size: %"PRId32" != %d\n",
 			msg->size, (int)sizeof(VhostUserLog));
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	size = msg->payload.log.mmap_size;
@@ -1233,7 +1267,7 @@ vhost_user_set_log_base(struct virtio_net *dev, struct VhostUserMsg *msg)
 		RTE_LOG(ERR, VHOST_CONFIG,
 			"log offset %#"PRIx64" exceeds log size %#"PRIx64"\n",
 			off, size);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	RTE_LOG(INFO, VHOST_CONFIG,
@@ -1248,7 +1282,7 @@ vhost_user_set_log_base(struct virtio_net *dev, struct VhostUserMsg *msg)
 	close(fd);
 	if (addr == MAP_FAILED) {
 		RTE_LOG(ERR, VHOST_CONFIG, "mmap log base failed!\n");
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	/*
@@ -1264,14 +1298,16 @@ vhost_user_set_log_base(struct virtio_net *dev, struct VhostUserMsg *msg)
 
 	msg->size = sizeof(msg->payload.u64);
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
-static void vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
+static int vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
 			struct VhostUserMsg *msg)
 {
 	close(msg->fds[0]);
 	RTE_LOG(INFO, VHOST_CONFIG, "not implemented.\n");
+
+	return VH_RESULT_OK;
 }
 
 /*
@@ -1283,8 +1319,9 @@ static void vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
  * a flag 'broadcast_rarp' to let rte_vhost_dequeue_burst() inject it.
  */
 static int
-vhost_user_send_rarp(struct virtio_net *dev, struct VhostUserMsg *msg)
+vhost_user_send_rarp(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	uint8_t *mac = (uint8_t *)&msg->payload.u64;
 	struct rte_vdpa_device *vdpa_dev;
 	int did = -1;
@@ -1308,40 +1345,42 @@ vhost_user_send_rarp(struct virtio_net *dev, struct VhostUserMsg *msg)
 	if (vdpa_dev && vdpa_dev->ops->migration_done)
 		vdpa_dev->ops->migration_done(dev->vid);
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 static int
-vhost_user_net_set_mtu(struct virtio_net *dev, struct VhostUserMsg *msg)
+vhost_user_net_set_mtu(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	if (msg->payload.u64 < VIRTIO_MIN_MTU ||
 			msg->payload.u64 > VIRTIO_MAX_MTU) {
 		RTE_LOG(ERR, VHOST_CONFIG, "Invalid MTU size (%"PRIu64")\n",
 				msg->payload.u64);
 
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	dev->mtu = msg->payload.u64;
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 static int
-vhost_user_set_req_fd(struct virtio_net *dev, struct VhostUserMsg *msg)
+vhost_user_set_req_fd(struct virtio_net **pdev, struct VhostUserMsg *msg)
 {
+	struct virtio_net *dev = *pdev;
 	int fd = msg->fds[0];
 
 	if (fd < 0) {
 		RTE_LOG(ERR, VHOST_CONFIG,
 				"Invalid file descriptor for slave channel (%d)\n",
 				fd);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
 	dev->slave_req_fd = fd;
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 static int
@@ -1406,7 +1445,7 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg)
 		len = imsg->size;
 		vva = qva_to_vva(dev, imsg->uaddr, &len);
 		if (!vva)
-			return -1;
+			return VH_RESULT_ERR;
 
 		for (i = 0; i < dev->nr_vring; i++) {
 			struct vhost_virtqueue *vq = dev->virtqueue[i];
@@ -1432,10 +1471,10 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg)
 	default:
 		RTE_LOG(ERR, VHOST_CONFIG, "Invalid IOTLB message type (%d)\n",
 				imsg->type);
-		return -1;
+		return VH_RESULT_ERR;
 	}
 
-	return 0;
+	return VH_RESULT_OK;
 }
 
 /* return bytes# of read on success or negative val on failure. */
@@ -1685,26 +1724,26 @@ vhost_user_msg_handler(int vid, int fd)
 
 	switch (msg.request.master) {
 	case VHOST_USER_GET_FEATURES:
-		vhost_user_get_features(dev, &msg);
+		ret = vhost_user_get_features(&dev, &msg);
 		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_FEATURES:
-		ret = vhost_user_set_features(dev, msg.payload.u64);
+		ret = vhost_user_set_features(&dev, &msg);
 		break;
 
 	case VHOST_USER_GET_PROTOCOL_FEATURES:
-		vhost_user_get_protocol_features(dev, &msg);
+		ret = vhost_user_get_protocol_features(&dev, &msg);
 		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_PROTOCOL_FEATURES:
-		ret = vhost_user_set_protocol_features(dev, msg.payload.u64);
+		ret = vhost_user_set_protocol_features(&dev, &msg);
 		break;
 
 	case VHOST_USER_SET_OWNER:
-		ret = vhost_user_set_owner();
+		ret = vhost_user_set_owner(&dev, &msg);
 		break;
 	case VHOST_USER_RESET_OWNER:
-		ret = vhost_user_reset_owner(dev);
+		ret = vhost_user_reset_owner(&dev, &msg);
 		break;
 
 	case VHOST_USER_SET_MEM_TABLE:
@@ -1712,28 +1751,28 @@ vhost_user_msg_handler(int vid, int fd)
 		break;
 
 	case VHOST_USER_SET_LOG_BASE:
-		ret = vhost_user_set_log_base(dev, &msg);
+		ret = vhost_user_set_log_base(&dev, &msg);
 		if (ret)
 			goto skip_to_reply;
 		/* it needs a reply */
 		send_vhost_reply(fd, &msg);
 		break;
 	case VHOST_USER_SET_LOG_FD:
-		vhost_user_set_log_fd(&dev, &msg);
+		ret = vhost_user_set_log_fd(&dev, &msg);
 		break;
 
 	case VHOST_USER_SET_VRING_NUM:
-		ret = vhost_user_set_vring_num(dev, &msg);
+		ret = vhost_user_set_vring_num(&dev, &msg);
 		break;
 	case VHOST_USER_SET_VRING_ADDR:
 		ret = vhost_user_set_vring_addr(&dev, &msg);
 		break;
 	case VHOST_USER_SET_VRING_BASE:
-		ret = vhost_user_set_vring_base(dev, &msg);
+		ret = vhost_user_set_vring_base(&dev, &msg);
 		break;
 
 	case VHOST_USER_GET_VRING_BASE:
-		ret = vhost_user_get_vring_base(dev, &msg);
+		ret = vhost_user_get_vring_base(&dev, &msg);
 		if (ret)
 			goto skip_to_reply;
 		send_vhost_reply(fd, &msg);
@@ -1743,31 +1782,31 @@ vhost_user_msg_handler(int vid, int fd)
 		ret = vhost_user_set_vring_kick(&dev, &msg);
 		break;
 	case VHOST_USER_SET_VRING_CALL:
-		vhost_user_set_vring_call(dev, &msg);
+		ret = vhost_user_set_vring_call(&dev, &msg);
 		break;
 
 	case VHOST_USER_SET_VRING_ERR:
-		vhost_user_set_vring_err(&dev, &msg);
+		ret = vhost_user_set_vring_err(&dev, &msg);
 		break;
 
 	case VHOST_USER_GET_QUEUE_NUM:
-		vhost_user_get_queue_num(dev, &msg);
+		ret = vhost_user_get_queue_num(&dev, &msg);
 		send_vhost_reply(fd, &msg);
 		break;
 
 	case VHOST_USER_SET_VRING_ENABLE:
-		ret = vhost_user_set_vring_enable(dev, &msg);
+		ret = vhost_user_set_vring_enable(&dev, &msg);
 		break;
 	case VHOST_USER_SEND_RARP:
-		ret = vhost_user_send_rarp(dev, &msg);
+		ret = vhost_user_send_rarp(&dev, &msg);
 		break;
 
 	case VHOST_USER_NET_SET_MTU:
-		ret = vhost_user_net_set_mtu(dev, &msg);
+		ret = vhost_user_net_set_mtu(&dev, &msg);
 		break;
 
 	case VHOST_USER_SET_SLAVE_REQ_FD:
-		ret = vhost_user_set_req_fd(dev, &msg);
+		ret = vhost_user_set_req_fd(&dev, &msg);
 		break;
 
 	case VHOST_USER_IOTLB_MSG:

[PATCH v6 5/5] vhost: message handling implemented as a callback array

[Nikolay Nikolaev]

Introduce vhost_message_handlers, which maps the message request
type to the message handler. Then replace the switch construct
with a map and call.

Failing vhost_user_set_features is fatal and all processing should
stop immediately and propagate the error to the upper layers. Change
the code accordingly to reflect that.

Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
---
 lib/librte_vhost/vhost_user.c |  150 ++++++++++++++++-------------------------
 1 file changed, 57 insertions(+), 93 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index e1b705fa7..f6ce8e092 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1477,6 +1477,35 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg)
 	return VH_RESULT_OK;
 }
 
+typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
+					struct VhostUserMsg *msg);
+static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
+	[VHOST_USER_NONE] = NULL,
+	[VHOST_USER_GET_FEATURES] = vhost_user_get_features,
+	[VHOST_USER_SET_FEATURES] = vhost_user_set_features,
+	[VHOST_USER_SET_OWNER] = vhost_user_set_owner,
+	[VHOST_USER_RESET_OWNER] = vhost_user_reset_owner,
+	[VHOST_USER_SET_MEM_TABLE] = vhost_user_set_mem_table,
+	[VHOST_USER_SET_LOG_BASE] = vhost_user_set_log_base,
+	[VHOST_USER_SET_LOG_FD] = vhost_user_set_log_fd,
+	[VHOST_USER_SET_VRING_NUM] = vhost_user_set_vring_num,
+	[VHOST_USER_SET_VRING_ADDR] = vhost_user_set_vring_addr,
+	[VHOST_USER_SET_VRING_BASE] = vhost_user_set_vring_base,
+	[VHOST_USER_GET_VRING_BASE] = vhost_user_get_vring_base,
+	[VHOST_USER_SET_VRING_KICK] = vhost_user_set_vring_kick,
+	[VHOST_USER_SET_VRING_CALL] = vhost_user_set_vring_call,
+	[VHOST_USER_SET_VRING_ERR] = vhost_user_set_vring_err,
+	[VHOST_USER_GET_PROTOCOL_FEATURES] = vhost_user_get_protocol_features,
+	[VHOST_USER_SET_PROTOCOL_FEATURES] = vhost_user_set_protocol_features,
+	[VHOST_USER_GET_QUEUE_NUM] = vhost_user_get_queue_num,
+	[VHOST_USER_SET_VRING_ENABLE] = vhost_user_set_vring_enable,
+	[VHOST_USER_SEND_RARP] = vhost_user_send_rarp,
+	[VHOST_USER_NET_SET_MTU] = vhost_user_net_set_mtu,
+	[VHOST_USER_SET_SLAVE_REQ_FD] = vhost_user_set_req_fd,
+	[VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
+};
+
+
 /* return bytes# of read on success or negative val on failure. */
 static int
 read_vhost_message(int sockfd, struct VhostUserMsg *msg)
@@ -1630,6 +1659,7 @@ vhost_user_msg_handler(int vid, int fd)
 	int ret;
 	int unlock_required = 0;
 	uint32_t skip_master = 0;
+	int request;
 
 	dev = get_device(vid);
 	if (dev == NULL)
@@ -1722,100 +1752,34 @@ vhost_user_msg_handler(int vid, int fd)
 			goto skip_to_post_handle;
 	}
 
-	switch (msg.request.master) {
-	case VHOST_USER_GET_FEATURES:
-		ret = vhost_user_get_features(&dev, &msg);
-		send_vhost_reply(fd, &msg);
-		break;
-	case VHOST_USER_SET_FEATURES:
-		ret = vhost_user_set_features(&dev, &msg);
-		break;
-
-	case VHOST_USER_GET_PROTOCOL_FEATURES:
-		ret = vhost_user_get_protocol_features(&dev, &msg);
-		send_vhost_reply(fd, &msg);
-		break;
-	case VHOST_USER_SET_PROTOCOL_FEATURES:
-		ret = vhost_user_set_protocol_features(&dev, &msg);
-		break;
-
-	case VHOST_USER_SET_OWNER:
-		ret = vhost_user_set_owner(&dev, &msg);
-		break;
-	case VHOST_USER_RESET_OWNER:
-		ret = vhost_user_reset_owner(&dev, &msg);
-		break;
-
-	case VHOST_USER_SET_MEM_TABLE:
-		ret = vhost_user_set_mem_table(&dev, &msg);
-		break;
-
-	case VHOST_USER_SET_LOG_BASE:
-		ret = vhost_user_set_log_base(&dev, &msg);
-		if (ret)
-			goto skip_to_reply;
-		/* it needs a reply */
-		send_vhost_reply(fd, &msg);
-		break;
-	case VHOST_USER_SET_LOG_FD:
-		ret = vhost_user_set_log_fd(&dev, &msg);
-		break;
-
-	case VHOST_USER_SET_VRING_NUM:
-		ret = vhost_user_set_vring_num(&dev, &msg);
-		break;
-	case VHOST_USER_SET_VRING_ADDR:
-		ret = vhost_user_set_vring_addr(&dev, &msg);
-		break;
-	case VHOST_USER_SET_VRING_BASE:
-		ret = vhost_user_set_vring_base(&dev, &msg);
-		break;
-
-	case VHOST_USER_GET_VRING_BASE:
-		ret = vhost_user_get_vring_base(&dev, &msg);
-		if (ret)
-			goto skip_to_reply;
-		send_vhost_reply(fd, &msg);
-		break;
-
-	case VHOST_USER_SET_VRING_KICK:
-		ret = vhost_user_set_vring_kick(&dev, &msg);
-		break;
-	case VHOST_USER_SET_VRING_CALL:
-		ret = vhost_user_set_vring_call(&dev, &msg);
-		break;
-
-	case VHOST_USER_SET_VRING_ERR:
-		ret = vhost_user_set_vring_err(&dev, &msg);
-		break;
-
-	case VHOST_USER_GET_QUEUE_NUM:
-		ret = vhost_user_get_queue_num(&dev, &msg);
-		send_vhost_reply(fd, &msg);
-		break;
-
-	case VHOST_USER_SET_VRING_ENABLE:
-		ret = vhost_user_set_vring_enable(&dev, &msg);
-		break;
-	case VHOST_USER_SEND_RARP:
-		ret = vhost_user_send_rarp(&dev, &msg);
-		break;
-
-	case VHOST_USER_NET_SET_MTU:
-		ret = vhost_user_net_set_mtu(&dev, &msg);
-		break;
-
-	case VHOST_USER_SET_SLAVE_REQ_FD:
-		ret = vhost_user_set_req_fd(&dev, &msg);
-		break;
-
-	case VHOST_USER_IOTLB_MSG:
-		ret = vhost_user_iotlb_msg(&dev, &msg);
-		break;
+	request = msg.request.master;
+	if (request > VHOST_USER_NONE && request < VHOST_USER_MAX) {
+		if (!vhost_message_handlers[request])
+			goto skip_to_post_handle;
+		ret = vhost_message_handlers[request](&dev, &msg);
 
-	default:
-		ret = -1;
-		break;
+		switch (ret) {
+		case VH_RESULT_ERR:
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"Processing %s failed.\n",
+				vhost_message_str[request]);
+			break;
+		case VH_RESULT_OK:
+			RTE_LOG(DEBUG, VHOST_CONFIG,
+				"Processing %s succeeded.\n",
+				vhost_message_str[request]);
+			break;
+		case VH_RESULT_REPLY:
+			RTE_LOG(INFO, VHOST_CONFIG,
+				"Processing %s succeeded and needs reply.\n",
+				vhost_message_str[request]);
+			send_vhost_reply(fd, &msg);
+			break;
+		}
+	} else {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"Requested invalid message type %d.\n", request);
+		ret = VH_RESULT_ERR;
 	}
 
 skip_to_post_handle:

Re: [PATCH v6 1/5] vhost: unify struct VhostUserMsg usage

[Burakov, Anatoly]

On 24-Sep-18 9:17 PM, Nikolay Nikolaev wrote:
> Do not use the typedef version of struct VhostUserMsg. Also unify the
> related parameter name.
> 
> Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
> ---

Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>

-- 
Thanks,
Anatoly

Re: [PATCH v6 2/5] vhost: make message handling functions prepare the reply

[Burakov, Anatoly]

On 24-Sep-18 9:17 PM, Nikolay Nikolaev wrote:
> As VhostUserMsg structure is reused to generate the reply, move the
> relevant fields update into the respective message handling functions.
> 
> Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
> ---

Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>

-- 
Thanks,
Anatoly

Re: [PATCH v6 3/5] vhost: handle unsupported message types in functions

[Burakov, Anatoly]

On 24-Sep-18 9:17 PM, Nikolay Nikolaev wrote:
> Add new functions to handle the unsupported vhost message types:
>   - vhost_user_set_vring_err
>   - vhost_user_set_log_fd
> 
> Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
> ---

Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>

-- 
Thanks,
Anatoly

Re: [PATCH v6 5/5] vhost: message handling implemented as a callback array

[Maxime Coquelin]

Hi Nikolay,

On 09/24/2018 10:17 PM, Nikolay Nikolaev wrote:
> +		switch (ret) {
> +		case VH_RESULT_ERR:
> +			RTE_LOG(ERR, VHOST_CONFIG,
> +				"Processing %s failed.\n",
> +				vhost_message_str[request]);
> +			break;
> +		case VH_RESULT_OK:
> +			RTE_LOG(DEBUG, VHOST_CONFIG,
> +				"Processing %s succeeded.\n",
> +				vhost_message_str[request]);
> +			break;
> +		case VH_RESULT_REPLY:
> +			RTE_LOG(INFO, VHOST_CONFIG,
I would prefer having it has DEBUG log level, do you agree?
If so, no need to resend for it, I can fixup while applying.

> +				"Processing %s succeeded and needs reply.\n",
> +				vhost_message_str[request]);
> +			send_vhost_reply(fd, &msg);
> +			break;
> +		}

Thanks,
Maxime

Re: [PATCH v6 0/5] vhost: vhost_user.c code cleanup

[Maxime Coquelin]

Hi Nikolay,

On 09/24/2018 10:16 PM, Nikolay Nikolaev wrote:
> vhost: vhost_user.c code cleanup
> 
> This patchesries introduce a set of code redesigns in vhost_user.c.
> 
> The goal is to unify and simplify vhost-user message handling. The
> patches do not intend to introduce any functional changes.
> 
> v6 changes:
>   - Even more fixes to the usage of struct VhostUserMsg in
>     the patches (Anatoly Burakov)
> 
> v5 changes:
>   - fixed the usage of struct VhostUserMsg in all patches (Anatoly Burakov)
> 
> v4 changes:
>   - use struct VhostUserMsg as the coding style guide suggests (Anatoly Burakov)
>   - VH_RESULT_FATAL is removed as not needed anymore (Maxime Coquelin)
> 
> v3 changes:
>   - rebased on top of git://dpdk.org/next/dpdk-next-virtio dead0602
>   - introduce VH_RESULT_FATAL (Maxime Coquelin)
>   - vhost_user_set_features return VH_RESULT_FATAL on failure.
>     This allows keeping the propagate error logic (Ilya Maximets)
>   - fixed vhost_user_set_vring_kick and vhost_user_set_protocol_features
>     return VH_RESULT_ERR upon failure
>   - fixed missing break in case VH_RESULT_ERR (Ilya Maximets)
>   - fixed a type on the description of 2/5 patch (Maxime Coquelin)
> 
> v2 changes:
>   - Fix the comments by Tiwei Bie
>   - Keep the old behavior
>     - Fall through when the callback returns VH_RESULT_ERR
>     - Fall through if the request is out of range
> 
> ---
> 
> Nikolay Nikolaev (5):
>        vhost: unify struct VhostUserMsg usage
>        vhost: make message handling functions prepare the reply
>        vhost: handle unsupported message types in functions
>        vhost: unify message handling function signature
>        vhost: message handling implemented as a callback array
> 
> 
>   lib/librte_vhost/vhost_user.c |  394 ++++++++++++++++++++++-------------------
>   1 file changed, 209 insertions(+), 185 deletions(-)
> 
> --
> Signature
> 

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Series applied to dpdk-next-virtio with small change I suggested in
patch 5.

Thanks for your contribution!
Maxime

Re: [PATCH v6 5/5] vhost: message handling implemented as a callback array

[Maxime Coquelin]

Hi Nikolay,

On 09/24/2018 10:17 PM, Nikolay Nikolaev wrote:
> Introduce vhost_message_handlers, which maps the message request
> type to the message handler. Then replace the switch construct
> with a map and call.
> 
> Failing vhost_user_set_features is fatal and all processing should
> stop immediately and propagate the error to the upper layers. Change
> the code accordingly to reflect that.
> 
> Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
> ---
>   lib/librte_vhost/vhost_user.c |  150 ++++++++++++++++-------------------------
>   1 file changed, 57 insertions(+), 93 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index e1b705fa7..f6ce8e092 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1477,6 +1477,35 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg)
>   	return VH_RESULT_OK;
>   }
>   
> +typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
> +					struct VhostUserMsg *msg);
> +static vhost_message_handler_t vhost_message_handlers[VHOST_USER_MAX] = {
> +	[VHOST_USER_NONE] = NULL,
> +	[VHOST_USER_GET_FEATURES] = vhost_user_get_features,
> +	[VHOST_USER_SET_FEATURES] = vhost_user_set_features,
> +	[VHOST_USER_SET_OWNER] = vhost_user_set_owner,
> +	[VHOST_USER_RESET_OWNER] = vhost_user_reset_owner,
> +	[VHOST_USER_SET_MEM_TABLE] = vhost_user_set_mem_table,
> +	[VHOST_USER_SET_LOG_BASE] = vhost_user_set_log_base,
> +	[VHOST_USER_SET_LOG_FD] = vhost_user_set_log_fd,
> +	[VHOST_USER_SET_VRING_NUM] = vhost_user_set_vring_num,
> +	[VHOST_USER_SET_VRING_ADDR] = vhost_user_set_vring_addr,
> +	[VHOST_USER_SET_VRING_BASE] = vhost_user_set_vring_base,
> +	[VHOST_USER_GET_VRING_BASE] = vhost_user_get_vring_base,
> +	[VHOST_USER_SET_VRING_KICK] = vhost_user_set_vring_kick,
> +	[VHOST_USER_SET_VRING_CALL] = vhost_user_set_vring_call,
> +	[VHOST_USER_SET_VRING_ERR] = vhost_user_set_vring_err,
> +	[VHOST_USER_GET_PROTOCOL_FEATURES] = vhost_user_get_protocol_features,
> +	[VHOST_USER_SET_PROTOCOL_FEATURES] = vhost_user_set_protocol_features,
> +	[VHOST_USER_GET_QUEUE_NUM] = vhost_user_get_queue_num,
> +	[VHOST_USER_SET_VRING_ENABLE] = vhost_user_set_vring_enable,
> +	[VHOST_USER_SEND_RARP] = vhost_user_send_rarp,
> +	[VHOST_USER_NET_SET_MTU] = vhost_user_net_set_mtu,
> +	[VHOST_USER_SET_SLAVE_REQ_FD] = vhost_user_set_req_fd,
> +	[VHOST_USER_IOTLB_MSG] = vhost_user_iotlb_msg,
> +};
> +
> +
>   /* return bytes# of read on success or negative val on failure. */
>   static int
>   read_vhost_message(int sockfd, struct VhostUserMsg *msg)
> @@ -1630,6 +1659,7 @@ vhost_user_msg_handler(int vid, int fd)
>   	int ret;
>   	int unlock_required = 0;
>   	uint32_t skip_master = 0;
> +	int request;
>   
>   	dev = get_device(vid);
>   	if (dev == NULL)
> @@ -1722,100 +1752,34 @@ vhost_user_msg_handler(int vid, int fd)
>   			goto skip_to_post_handle;
>   	}
>   
> -	switch (msg.request.master) {
> -	case VHOST_USER_GET_FEATURES:
> -		ret = vhost_user_get_features(&dev, &msg);
> -		send_vhost_reply(fd, &msg);
> -		break;
> -	case VHOST_USER_SET_FEATURES:
> -		ret = vhost_user_set_features(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_GET_PROTOCOL_FEATURES:
> -		ret = vhost_user_get_protocol_features(&dev, &msg);
> -		send_vhost_reply(fd, &msg);
> -		break;
> -	case VHOST_USER_SET_PROTOCOL_FEATURES:
> -		ret = vhost_user_set_protocol_features(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_SET_OWNER:
> -		ret = vhost_user_set_owner(&dev, &msg);
> -		break;
> -	case VHOST_USER_RESET_OWNER:
> -		ret = vhost_user_reset_owner(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_SET_MEM_TABLE:
> -		ret = vhost_user_set_mem_table(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_SET_LOG_BASE:
> -		ret = vhost_user_set_log_base(&dev, &msg);
> -		if (ret)
> -			goto skip_to_reply;
> -		/* it needs a reply */
> -		send_vhost_reply(fd, &msg);
> -		break;
> -	case VHOST_USER_SET_LOG_FD:
> -		ret = vhost_user_set_log_fd(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_SET_VRING_NUM:
> -		ret = vhost_user_set_vring_num(&dev, &msg);
> -		break;
> -	case VHOST_USER_SET_VRING_ADDR:
> -		ret = vhost_user_set_vring_addr(&dev, &msg);
> -		break;
> -	case VHOST_USER_SET_VRING_BASE:
> -		ret = vhost_user_set_vring_base(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_GET_VRING_BASE:
> -		ret = vhost_user_get_vring_base(&dev, &msg);
> -		if (ret)
> -			goto skip_to_reply;
> -		send_vhost_reply(fd, &msg);
> -		break;
> -
> -	case VHOST_USER_SET_VRING_KICK:
> -		ret = vhost_user_set_vring_kick(&dev, &msg);
> -		break;
> -	case VHOST_USER_SET_VRING_CALL:
> -		ret = vhost_user_set_vring_call(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_SET_VRING_ERR:
> -		ret = vhost_user_set_vring_err(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_GET_QUEUE_NUM:
> -		ret = vhost_user_get_queue_num(&dev, &msg);
> -		send_vhost_reply(fd, &msg);
> -		break;
> -
> -	case VHOST_USER_SET_VRING_ENABLE:
> -		ret = vhost_user_set_vring_enable(&dev, &msg);
> -		break;
> -	case VHOST_USER_SEND_RARP:
> -		ret = vhost_user_send_rarp(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_NET_SET_MTU:
> -		ret = vhost_user_net_set_mtu(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_SET_SLAVE_REQ_FD:
> -		ret = vhost_user_set_req_fd(&dev, &msg);
> -		break;
> -
> -	case VHOST_USER_IOTLB_MSG:
> -		ret = vhost_user_iotlb_msg(&dev, &msg);
> -		break;
> +	request = msg.request.master;
> +	if (request > VHOST_USER_NONE && request < VHOST_USER_MAX) {
> +		if (!vhost_message_handlers[request])
> +			goto skip_to_post_handle;
> +		ret = vhost_message_handlers[request](&dev, &msg);

Have you tested the series?
In case ret == VH_RESULT_REPLY, like the first request (GET_FEATURES),
it fails because ret is tested as non-zero afterwards to detect
failures.

>   
> -	default:
> -		ret = -1;
> -		break;
> +		switch (ret) {
> +		case VH_RESULT_ERR:
> +			RTE_LOG(ERR, VHOST_CONFIG,
> +				"Processing %s failed.\n",
> +				vhost_message_str[request]);
> +			break;
> +		case VH_RESULT_OK:
> +			RTE_LOG(DEBUG, VHOST_CONFIG,
> +				"Processing %s succeeded.\n",
> +				vhost_message_str[request]);
> +			break;
> +		case VH_RESULT_REPLY:
> +			RTE_LOG(INFO, VHOST_CONFIG,
> +				"Processing %s succeeded and needs reply.\n",
> +				vhost_message_str[request]);
> +			send_vhost_reply(fd, &msg);
> +			break;
> +		}
> +	} else {
> +		RTE_LOG(ERR, VHOST_CONFIG,
> +			"Requested invalid message type %d.\n", request);
> +		ret = VH_RESULT_ERR;
>   	}
>   
>   skip_to_post_handle:
> 

Re: [PATCH v6 4/5] vhost: unify message handling function signature

[Maxime Coquelin]

On 09/24/2018 10:17 PM, Nikolay Nikolaev wrote:
> Each vhost-user message handling function will return an int result
> which is described in the new enum vh_result: error, OK and reply.
> All functions will now have two arguments, virtio_net double pointer
> and VhostUserMsg pointer.
> 
> Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
> ---
>   lib/librte_vhost/vhost_user.c |  211 ++++++++++++++++++++++++-----------------
>   1 file changed, 125 insertions(+), 86 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 77905dda0..e1b705fa7 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -71,6 +71,16 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
>   	[VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
>   };
>   
> +/* The possible results of a message handling function */
> +enum vh_result {
> +	/* Message handling failed */
> +	VH_RESULT_ERR   = -1,
> +	/* Message handling successful */
> +	VH_RESULT_OK    =  0,
> +	/* Message handling successful and reply prepared */
> +	VH_RESULT_REPLY =  1,
> +};
> +


> -vhost_user_get_vring_base(struct virtio_net *dev,
> +vhost_user_get_vring_base(struct virtio_net **pdev,
>   			  struct VhostUserMsg *msg)
>   {
> +	struct virtio_net *dev = *pdev;
>   	struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
>   
>   	/* We have to stop the queue (virtio) if it is running. */
> @@ -1135,7 +1161,7 @@ vhost_user_get_vring_base(struct virtio_net *dev,
>   
>   	msg->size = sizeof(msg->payload.state);
>   
> -	return 0;
> +	return VH_RESULT_OK;
>   }

VH_RESULT_REPLY here.

> -static void
> -vhost_user_get_protocol_features(struct virtio_net *dev,
> +static int
> +vhost_user_get_protocol_features(struct virtio_net **pdev,
>   				 struct VhostUserMsg *msg)
>   {
> +	struct virtio_net *dev = *pdev;
>   	uint64_t features, protocol_features;
>   
>   	rte_vhost_driver_get_features(dev->ifname, &features);
> @@ -1189,40 +1217,46 @@ vhost_user_get_protocol_features(struct virtio_net *dev,
>   
>   	msg->payload.u64 = protocol_features;
>   	msg->size = sizeof(msg->payload.u64);
> +
> +	return VH_RESULT_OK;
>   }

Ditto.

I have the patches to fix these, it will be posted as preliminary part 
of my postcopy series.

Please, next time, test your series before posting.

Thanks,
Maxime

Re: [PATCH v6 4/5] vhost: unify message handling function signature

[Nikolay Nikolaev]

On Tue, Oct 2, 2018 at 11:59 AM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
>
>
> On 09/24/2018 10:17 PM, Nikolay Nikolaev wrote:
> > Each vhost-user message handling function will return an int result
> > which is described in the new enum vh_result: error, OK and reply.
> > All functions will now have two arguments, virtio_net double pointer
> > and VhostUserMsg pointer.
> >
> > Signed-off-by: Nikolay Nikolaev <nicknickolaev@gmail.com>
> > ---
> >   lib/librte_vhost/vhost_user.c |  211 ++++++++++++++++++++++++-----------------
> >   1 file changed, 125 insertions(+), 86 deletions(-)
> >
> > diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> > index 77905dda0..e1b705fa7 100644
> > --- a/lib/librte_vhost/vhost_user.c
> > +++ b/lib/librte_vhost/vhost_user.c
> > @@ -71,6 +71,16 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
> >       [VHOST_USER_CRYPTO_CLOSE_SESS] = "VHOST_USER_CRYPTO_CLOSE_SESS",
> >   };
> >
> > +/* The possible results of a message handling function */
> > +enum vh_result {
> > +     /* Message handling failed */
> > +     VH_RESULT_ERR   = -1,
> > +     /* Message handling successful */
> > +     VH_RESULT_OK    =  0,
> > +     /* Message handling successful and reply prepared */
> > +     VH_RESULT_REPLY =  1,
> > +};
> > +
>
>
> > -vhost_user_get_vring_base(struct virtio_net *dev,
> > +vhost_user_get_vring_base(struct virtio_net **pdev,
> >                         struct VhostUserMsg *msg)
> >   {
> > +     struct virtio_net *dev = *pdev;
> >       struct vhost_virtqueue *vq = dev->virtqueue[msg->payload.state.index];
> >
> >       /* We have to stop the queue (virtio) if it is running. */
> > @@ -1135,7 +1161,7 @@ vhost_user_get_vring_base(struct virtio_net *dev,
> >
> >       msg->size = sizeof(msg->payload.state);
> >
> > -     return 0;
> > +     return VH_RESULT_OK;
> >   }
>
> VH_RESULT_REPLY here.
>
> > -static void
> > -vhost_user_get_protocol_features(struct virtio_net *dev,
> > +static int
> > +vhost_user_get_protocol_features(struct virtio_net **pdev,
> >                                struct VhostUserMsg *msg)
> >   {
> > +     struct virtio_net *dev = *pdev;
> >       uint64_t features, protocol_features;
> >
> >       rte_vhost_driver_get_features(dev->ifname, &features);
> > @@ -1189,40 +1217,46 @@ vhost_user_get_protocol_features(struct virtio_net *dev,
> >
> >       msg->payload.u64 = protocol_features;
> >       msg->size = sizeof(msg->payload.u64);
> > +
> > +     return VH_RESULT_OK;
> >   }
>
> Ditto.
>
> I have the patches to fix these, it will be posted as preliminary part
> of my postcopy series.
>
> Please, next time, test your series before posting.

Oh, sorry for that. I obviously underestimated the complexity of the refactoring
and indeed did not test beyond compilation and visual code inspect,
which of course can not be excused.
I guess at least running the vhost sample against qemu would have
shown these issues.

I'm sorry again, I could have done better.

regards,
Nikolay Nikolaev

>
> Thanks,
> Maxime