On 26-Jan-18 3:41 AM, Jianfeng Tan wrote:
Previouly, there are three channels for multi-process
(i.e., primary/secondary) communication.
1. Config-file based channel, in which, the primary process writes
info into a pre-defined config file, and the secondary process
reads the info out.
2. vfio submodule has its own channel based on unix socket for the
secondary process to get container fd and group fd from the
primary process.
3. pdump submodule also has its own channel based on unix socket for
packet dump.
It'd be good to have a generic communication channel for multi-process
communication to accommodate the requirements including:
a. Secondary wants to send info to primary, for example, secondary
would like to send request (about some specific vdev to primary).
b. Sending info at any time, instead of just initialization time.
c. Share FDs with the other side, for vdev like vhost, related FDs
(memory region, kick) should be shared.
d. A send message request needs the other side to response immediately.
This patch proposes to create a communication channel, based on datagram
unix socket, for above requirements. Each process will block on a unix
socket waiting for messages from the peers.
Three new APIs are added:
1. rte_eal_mp_action_register() is used to register an action,
indexed by a string, when a component at receiver side would like
to response the messages from the peer processe.
2. rte_eal_mp_action_unregister() is used to unregister the action
if the calling component does not want to response the messages.
3. rte_eal_mp_sendmsg() is used to send a message, and returns
immediately. If there are n secondary processes, the primary
process will send n messages.
Suggested-by: Konstantin Ananyev <konstantin.anan...@intel.com>
Signed-off-by: Jianfeng Tan <jianfeng....@intel.com>
Reviewed-by: Anatoly Burakov <anatoly.bura...@intel.com>
Acked-by: Konstantin Ananyev <konstantin.anan...@intel.com>
---
<snip>
+
+static int
+mp_send(struct rte_mp_msg *msg)
+{
+ int ret = 0;
+ DIR *mp_dir;
+ struct dirent *ent;
+
+ if (rte_eal_process_type() == RTE_PROC_SECONDARY) {
+ if (send_msg(eal_mp_socket_path(), msg) < 0)
+ return -1;
+ else
+ return 0;
+ }
+
+ /* broadcast to all secondary processes */
+ mp_dir = opendir(mp_dir_path);
+ if (!mp_dir) {
+ RTE_LOG(ERR, EAL, "Unable to open directory %s\n",
+ mp_dir_path);
+ rte_errno = errno;
+ return -1;
+ }
+ while ((ent = readdir(mp_dir))) {
+ if (fnmatch(mp_filter, ent->d_name, 0) != 0)
+ continue;
+
+ if (send_msg(ent->d_name, msg) < 0)
+ ret = -1;
+ }
+ closedir(mp_dir);
+
+ return ret;
Nitpick: you probably don't need ret here, just return 0 as in other places.
+}
+
+static bool
+check_input(const struct rte_mp_msg *msg)
+{
+ if (msg == NULL) {
+ RTE_LOG(ERR, EAL, "Msg cannot be NULL\n");
+ rte_errno = -EINVAL;
+ return false;
+ }
+
+ if (validate_action_name(msg->name))
+ return false;
+
+ if (msg->len_param > RTE_MP_MAX_PARAM_LEN) {
+ RTE_LOG(ERR, EAL, "Message data is too long\n");
+ rte_errno = -E2BIG;
+ return false;
+ }
+
+ if (msg->num_fds > RTE_MP_MAX_FD_NUM) {
+ RTE_LOG(ERR, EAL, "Cannot send more than %d FDs\n",
+ RTE_MP_MAX_FD_NUM);
+ rte_errno = -E2BIG;
+ return false;
Otherwise, i'm happy with this patch.
--
Thanks,
Anatoly
