[dpdk-dev] [PATCH v3 18/22] vhost: introduce API to start a specific driver
Yuanhan Liu
yuanhan.liu at linux.intel.com
Tue Mar 28 14:45:38 CEST 2017
We used to use rte_vhost_driver_session_start() to trigger the vhost-user
session. It takes no argument, thus it's a global trigger. And it could
be problematic.
The issue is, currently, rte_vhost_driver_register(path, flags) actually
tries to put it into the session loop (by fdset_add). However, it needs
a set of APIs to set a vhost-user driver properly:
* rte_vhost_driver_register(path, flags);
* rte_vhost_driver_set_features(path, features);
* rte_vhost_driver_callback_register(path, vhost_device_ops);
If a new vhost-user driver is registered after the trigger (think OVS-DPDK
that could add a port dynamically from cmdline), the current code will
effectively starts the session for the new driver just after the first
API rte_vhost_driver_register() is invoked, leaving later calls taking
no effect at all.
To handle the case properly, this patch introduce a new API,
rte_vhost_driver_start(path), to trigger a specific vhost-user driver.
To do that, the rte_vhost_driver_register(path, flags) is simplified
to create the socket only and let rte_vhost_driver_start(path) to
actually put it into the session loop.
Meanwhile, the rte_vhost_driver_session_start is removed: we could hide
the session thread internally (create the thread if it has not been
created). This would also simplify the application.
NOTE: the API order in prog guide is slightly adjusted for showing the
correct invoke order.
Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
---
v3: - fix broken reconnect
---
doc/guides/prog_guide/vhost_lib.rst | 24 +++++-----
doc/guides/rel_notes/release_17_05.rst | 8 ++++
drivers/net/vhost/rte_eth_vhost.c | 50 ++------------------
examples/tep_termination/main.c | 8 +++-
examples/vhost/main.c | 9 +++-
lib/librte_vhost/fd_man.c | 9 ++--
lib/librte_vhost/fd_man.h | 2 +-
lib/librte_vhost/rte_vhost_version.map | 2 +-
lib/librte_vhost/rte_virtio_net.h | 15 +++++-
lib/librte_vhost/socket.c | 84 ++++++++++++++++++++--------------
10 files changed, 108 insertions(+), 103 deletions(-)
diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
index a4fb1f1..5979290 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -116,12 +116,6 @@ The following is an overview of some key Vhost API functions:
vhost-user driver could be vhost-user net, yet it could be something else,
say, vhost-user SCSI.
-* ``rte_vhost_driver_session_start()``
-
- This function starts the vhost session loop to handle vhost messages. It
- starts an infinite loop, therefore it should be called in a dedicated
- thread.
-
* ``rte_vhost_driver_callback_register(path, vhost_device_ops)``
This function registers a set of callbacks, to let DPDK applications take
@@ -149,6 +143,17 @@ The following is an overview of some key Vhost API functions:
``VHOST_F_LOG_ALL`` will be set/cleared at the start/end of live
migration, respectively.
+* ``rte_vhost_driver_disable/enable_features(path, features))``
+
+ This function disables/enables some features. For example, it can be used to
+ disable mergeable buffers and TSO features, which both are enabled by
+ default.
+
+* ``rte_vhost_driver_start(path)``
+
+ This function triggers the vhost-user negotiation. It should be invoked at
+ the end of initializing a vhost-user driver.
+
* ``rte_vhost_enqueue_burst(vid, queue_id, pkts, count)``
Transmits (enqueues) ``count`` packets from host to guest.
@@ -157,13 +162,6 @@ The following is an overview of some key Vhost API functions:
Receives (dequeues) ``count`` packets from guest, and stored them at ``pkts``.
-* ``rte_vhost_driver_disable/enable_features(path, features))``
-
- This function disables/enables some features. For example, it can be used to
- disable mergeable buffers and TSO features, which both are enabled by
- default.
-
-
Vhost-user Implementations
--------------------------
diff --git a/doc/guides/rel_notes/release_17_05.rst b/doc/guides/rel_notes/release_17_05.rst
index 2efe292..8f06fc4 100644
--- a/doc/guides/rel_notes/release_17_05.rst
+++ b/doc/guides/rel_notes/release_17_05.rst
@@ -57,6 +57,11 @@ New Features
* Enable Vhost PMD's MTU get feature.
* Get max MTU value from host in Virtio PMD
+* **Made the vhost lib be a generic vhost-user lib.**
+
+ Now it could be used to implement any other vhost-user drivers, such
+ as, vhost-user SCSI.
+
Resolved Issues
---------------
@@ -157,6 +162,9 @@ API Changes
* The vhost struct ``virtio_net_device_ops`` is renamed to
``vhost_device_ops``
+ * The vhost API ``rte_vhost_driver_session_start`` is removed. Instead,
+ ``rte_vhost_driver_start`` should be used.
+
ABI Changes
-----------
diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
index 97a765f..e6c0758 100644
--- a/drivers/net/vhost/rte_eth_vhost.c
+++ b/drivers/net/vhost/rte_eth_vhost.c
@@ -127,9 +127,6 @@ struct internal_list {
static pthread_mutex_t internal_list_lock = PTHREAD_MUTEX_INITIALIZER;
-static rte_atomic16_t nb_started_ports;
-static pthread_t session_th;
-
static struct rte_eth_link pmd_link = {
.link_speed = 10000,
.link_duplex = ETH_LINK_FULL_DUPLEX,
@@ -743,42 +740,6 @@ struct vhost_xstats_name_off {
return vid;
}
-static void *
-vhost_driver_session(void *param __rte_unused)
-{
- /* start event handling */
- rte_vhost_driver_session_start();
-
- return NULL;
-}
-
-static int
-vhost_driver_session_start(void)
-{
- int ret;
-
- ret = pthread_create(&session_th,
- NULL, vhost_driver_session, NULL);
- if (ret)
- RTE_LOG(ERR, PMD, "Can't create a thread\n");
-
- return ret;
-}
-
-static void
-vhost_driver_session_stop(void)
-{
- int ret;
-
- ret = pthread_cancel(session_th);
- if (ret)
- RTE_LOG(ERR, PMD, "Can't cancel the thread\n");
-
- ret = pthread_join(session_th, NULL);
- if (ret)
- RTE_LOG(ERR, PMD, "Can't join the thread\n");
-}
-
static int
eth_dev_start(struct rte_eth_dev *dev)
{
@@ -1083,10 +1044,10 @@ struct vhost_xstats_name_off {
goto error;
}
- /* We need only one message handling thread */
- if (rte_atomic16_add_return(&nb_started_ports, 1) == 1) {
- if (vhost_driver_session_start())
- goto error;
+ if (rte_vhost_driver_start(iface_name) < 0) {
+ RTE_LOG(ERR, PMD, "Failed to start driver for %s\n",
+ iface_name);
+ goto error;
}
return data->port_id;
@@ -1213,9 +1174,6 @@ struct vhost_xstats_name_off {
eth_dev_close(eth_dev);
- if (rte_atomic16_sub_return(&nb_started_ports, 1) == 0)
- vhost_driver_session_stop();
-
rte_free(vring_states[eth_dev->data->port_id]);
vring_states[eth_dev->data->port_id] = NULL;
diff --git a/examples/tep_termination/main.c b/examples/tep_termination/main.c
index 738f2d2..24c62cd 100644
--- a/examples/tep_termination/main.c
+++ b/examples/tep_termination/main.c
@@ -1263,7 +1263,13 @@ static inline void __attribute__((always_inline))
"failed to register vhost driver callbacks.\n");
}
- rte_vhost_driver_session_start();
+ if (rte_vhost_driver_start(dev_basename) < 0) {
+ rte_exit(EXIT_FAILURE,
+ "failed to start vhost driver.\n");
+ }
+
+ RTE_LCORE_FOREACH_SLAVE(lcore_id)
+ rte_eal_wait_lcore(lcore_id);
return 0;
}
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index 4395306..64b3eea 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -1545,9 +1545,16 @@ static inline void __attribute__((always_inline))
rte_exit(EXIT_FAILURE,
"failed to register vhost driver callbacks.\n");
}
+
+ if (rte_vhost_driver_start(file) < 0) {
+ rte_exit(EXIT_FAILURE,
+ "failed to start vhost driver.\n");
+ }
}
- rte_vhost_driver_session_start();
+ RTE_LCORE_FOREACH_SLAVE(lcore_id)
+ rte_eal_wait_lcore(lcore_id);
+
return 0;
}
diff --git a/lib/librte_vhost/fd_man.c b/lib/librte_vhost/fd_man.c
index c7a4490..2ceacc9 100644
--- a/lib/librte_vhost/fd_man.c
+++ b/lib/librte_vhost/fd_man.c
@@ -210,8 +210,8 @@
* will wait until the flag is reset to zero(which indicates the callback is
* finished), then it could free the context after fdset_del.
*/
-void
-fdset_event_dispatch(struct fdset *pfdset)
+void *
+fdset_event_dispatch(void *arg)
{
int i;
struct pollfd *pfd;
@@ -221,9 +221,10 @@
int fd, numfds;
int remove1, remove2;
int need_shrink;
+ struct fdset *pfdset = arg;
if (pfdset == NULL)
- return;
+ return NULL;
while (1) {
@@ -294,4 +295,6 @@
if (need_shrink)
fdset_shrink(pfdset);
}
+
+ return NULL;
}
diff --git a/lib/librte_vhost/fd_man.h b/lib/librte_vhost/fd_man.h
index d319cac..90d34db 100644
--- a/lib/librte_vhost/fd_man.h
+++ b/lib/librte_vhost/fd_man.h
@@ -64,6 +64,6 @@ int fdset_add(struct fdset *pfdset, int fd,
void *fdset_del(struct fdset *pfdset, int fd);
-void fdset_event_dispatch(struct fdset *pfdset);
+void *fdset_event_dispatch(void *arg);
#endif
diff --git a/lib/librte_vhost/rte_vhost_version.map b/lib/librte_vhost/rte_vhost_version.map
index f4b74da..0785873 100644
--- a/lib/librte_vhost/rte_vhost_version.map
+++ b/lib/librte_vhost/rte_vhost_version.map
@@ -4,7 +4,6 @@ DPDK_2.0 {
rte_vhost_dequeue_burst;
rte_vhost_driver_callback_register;
rte_vhost_driver_register;
- rte_vhost_driver_session_start;
rte_vhost_enable_guest_notification;
rte_vhost_enqueue_burst;
@@ -35,6 +34,7 @@ DPDK_17.05 {
rte_vhost_driver_enable_features;
rte_vhost_driver_get_features;
rte_vhost_driver_set_features;
+ rte_vhost_driver_start;
rte_vhost_get_mem_table;
rte_vhost_get_mtu;
rte_vhost_get_negotiated_features;
diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index 11b204d..627708d 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -250,8 +250,19 @@ void rte_vhost_log_used_vring(int vid, uint16_t vring_idx,
/* Register callbacks. */
int rte_vhost_driver_callback_register(const char *path,
struct vhost_device_ops const * const ops);
-/* Start vhost driver session blocking loop. */
-int rte_vhost_driver_session_start(void);
+
+/**
+ *
+ * Start the vhost-user driver.
+ *
+ * This function triggers the vhost-user negotiation.
+ *
+ * @param path
+ * The vhost-user socket file path
+ * @return
+ * 0 on success, -1 on failure
+ */
+int rte_vhost_driver_start(const char *path);
/**
* Get the MTU value of the device if set in QEMU.
diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index 9fb28b5..eb2aedd 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -63,7 +63,8 @@ struct vhost_user_socket {
struct vhost_user_connection_list conn_list;
pthread_mutex_t conn_mutex;
char *path;
- int listenfd;
+ int socket_fd;
+ struct sockaddr_un un;
bool is_server;
bool reconnect;
bool dequeue_zero_copy;
@@ -101,7 +102,8 @@ struct vhost_user {
static void vhost_user_server_new_connection(int fd, void *data, int *remove);
static void vhost_user_read_cb(int fd, void *dat, int *remove);
-static int vhost_user_create_client(struct vhost_user_socket *vsocket);
+static int create_unix_socket(struct vhost_user_socket *vsocket);
+static int vhost_user_start_client(struct vhost_user_socket *vsocket);
static struct vhost_user vhost_user = {
.fdset = {
@@ -280,23 +282,26 @@ struct vhost_user {
free(conn);
- if (vsocket->reconnect)
- vhost_user_create_client(vsocket);
+ if (vsocket->reconnect) {
+ create_unix_socket(vsocket);
+ vhost_user_start_client(vsocket);
+ }
}
}
static int
-create_unix_socket(const char *path, struct sockaddr_un *un, bool is_server)
+create_unix_socket(struct vhost_user_socket *vsocket)
{
int fd;
+ struct sockaddr_un *un = &vsocket->un;
fd = socket(AF_UNIX, SOCK_STREAM, 0);
if (fd < 0)
return -1;
RTE_LOG(INFO, VHOST_CONFIG, "vhost-user %s: socket created, fd: %d\n",
- is_server ? "server" : "client", fd);
+ vsocket->is_server ? "server" : "client", fd);
- if (!is_server && fcntl(fd, F_SETFL, O_NONBLOCK)) {
+ if (!vsocket->is_server && fcntl(fd, F_SETFL, O_NONBLOCK)) {
RTE_LOG(ERR, VHOST_CONFIG,
"vhost-user: can't set nonblocking mode for socket, fd: "
"%d (%s)\n", fd, strerror(errno));
@@ -306,25 +311,21 @@ struct vhost_user {
memset(un, 0, sizeof(*un));
un->sun_family = AF_UNIX;
- strncpy(un->sun_path, path, sizeof(un->sun_path));
+ strncpy(un->sun_path, vsocket->path, sizeof(un->sun_path));
un->sun_path[sizeof(un->sun_path) - 1] = '\0';
- return fd;
+ vsocket->socket_fd = fd;
+ return 0;
}
static int
-vhost_user_create_server(struct vhost_user_socket *vsocket)
+vhost_user_start_server(struct vhost_user_socket *vsocket)
{
- int fd;
int ret;
- struct sockaddr_un un;
+ int fd = vsocket->socket_fd;
const char *path = vsocket->path;
- fd = create_unix_socket(path, &un, vsocket->is_server);
- if (fd < 0)
- return -1;
-
- ret = bind(fd, (struct sockaddr *)&un, sizeof(un));
+ ret = bind(fd, (struct sockaddr *)&vsocket->un, sizeof(vsocket->un));
if (ret < 0) {
RTE_LOG(ERR, VHOST_CONFIG,
"failed to bind to %s: %s; remove it and try again\n",
@@ -337,7 +338,6 @@ struct vhost_user {
if (ret < 0)
goto err;
- vsocket->listenfd = fd;
ret = fdset_add(&vhost_user.fdset, fd, vhost_user_server_new_connection,
NULL, vsocket);
if (ret < 0) {
@@ -456,20 +456,15 @@ struct vhost_user_reconnect_list {
}
static int
-vhost_user_create_client(struct vhost_user_socket *vsocket)
+vhost_user_start_client(struct vhost_user_socket *vsocket)
{
- int fd;
int ret;
- struct sockaddr_un un;
+ int fd = vsocket->socket_fd;
const char *path = vsocket->path;
struct vhost_user_reconnect *reconn;
- fd = create_unix_socket(path, &un, vsocket->is_server);
- if (fd < 0)
- return -1;
-
- ret = vhost_user_connect_nonblock(fd, (struct sockaddr *)&un,
- sizeof(un));
+ ret = vhost_user_connect_nonblock(fd, (struct sockaddr *)&vsocket->un,
+ sizeof(vsocket->un));
if (ret == 0) {
vhost_user_add_connection(fd, vsocket);
return 0;
@@ -492,7 +487,7 @@ struct vhost_user_reconnect_list {
close(fd);
return -1;
}
- reconn->un = un;
+ reconn->un = vsocket->un;
reconn->fd = fd;
reconn->vsocket = vsocket;
pthread_mutex_lock(&reconn_list.mutex);
@@ -643,11 +638,10 @@ struct vhost_user_reconnect_list {
goto out;
}
}
- ret = vhost_user_create_client(vsocket);
} else {
vsocket->is_server = true;
- ret = vhost_user_create_server(vsocket);
}
+ ret = create_unix_socket(vsocket);
if (ret < 0) {
free(vsocket->path);
free(vsocket);
@@ -703,8 +697,8 @@ struct vhost_user_reconnect_list {
if (!strcmp(vsocket->path, path)) {
if (vsocket->is_server) {
- fdset_del(&vhost_user.fdset, vsocket->listenfd);
- close(vsocket->listenfd);
+ fdset_del(&vhost_user.fdset, vsocket->socket_fd);
+ close(vsocket->socket_fd);
unlink(path);
} else if (vsocket->reconnect) {
vhost_user_remove_reconnect(vsocket);
@@ -774,8 +768,28 @@ struct vhost_device_ops const *
}
int
-rte_vhost_driver_session_start(void)
+rte_vhost_driver_start(const char *path)
{
- fdset_event_dispatch(&vhost_user.fdset);
- return 0;
+ struct vhost_user_socket *vsocket;
+ static pthread_t fdset_tid;
+
+ pthread_mutex_lock(&vhost_user.mutex);
+ vsocket = find_vhost_user_socket(path);
+ pthread_mutex_unlock(&vhost_user.mutex);
+
+ if (!vsocket)
+ return -1;
+
+ if (fdset_tid == 0) {
+ int ret = pthread_create(&fdset_tid, NULL, fdset_event_dispatch,
+ &vhost_user.fdset);
+ if (ret < 0)
+ RTE_LOG(ERR, VHOST_CONFIG,
+ "failed to create fdset handling thread");
+ }
+
+ if (vsocket->is_server)
+ return vhost_user_start_server(vsocket);
+ else
+ return vhost_user_start_client(vsocket);
}
--
1.9.0
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