Commit a3c9d0fc authored by Mark Zhang's avatar Mark Zhang Committed by Leon Romanovsky
Browse files

RDMA/ucma: Support write an event into a CM 



Enable user-space to inject an event into a CM through it's event
channel. Two new events are added and supported: RDMA_CM_EVENT_USER and
RDMA_CM_EVENT_INTERNAL. With these 2 events a new event parameter "arg"
is supported, which is passed from sender to receiver transparently.

With this feature an application is able to write an event into a CM
channel with a new user-space rdmacm API. For example thread T1 could
write an event with the API:
    rdma_write_cm_event(cm_id, RDMA_CM_EVENT_USER, status, arg);
and thread T2 could receive the event with rdma_get_cm_event().

Signed-off-by: default avatarMark Zhang <markzhang@nvidia.com>
Reviewed-by: default avatarVlad Dumitrescu <vdumitrescu@nvidia.com>
Link: https://patch.msgid.link/fdf49d0b17a45933c5d8c1d90605c9447d9a3c73.1751279794.git.leonro@nvidia.com


Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent 810f874e

drivers/infiniband/core/ucma.c

+51 −1
Original line number Diff line number Diff line
@@ -1745,6 +1745,55 @@ static ssize_t ucma_migrate_id(struct ucma_file *new_file, 
	return ret;

}



static ssize_t ucma_write_cm_event(struct ucma_file *file,

				   const char __user *inbuf, int in_len,

				   int out_len)

{

	struct rdma_ucm_write_cm_event cmd;

	struct rdma_cm_event event = {};

	struct ucma_event *uevent;

	struct ucma_context *ctx;

	int ret = 0;



	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))

		return -EFAULT;



	if ((cmd.event != RDMA_CM_EVENT_USER) &&

	    (cmd.event != RDMA_CM_EVENT_INTERNAL))

		return -EINVAL;



	ctx = ucma_get_ctx(file, cmd.id);

	if (IS_ERR(ctx))

		return PTR_ERR(ctx);



	event.event = cmd.event;

	event.status = cmd.status;

	event.param.arg = cmd.param.arg;



	uevent = kzalloc(sizeof(*uevent), GFP_KERNEL);

	if (!uevent) {

		ret = -ENOMEM;

		goto out;

	}



	uevent->ctx = ctx;

	uevent->resp.uid = ctx->uid;

	uevent->resp.id = ctx->id;

	uevent->resp.event = event.event;

	uevent->resp.status = event.status;

	memcpy(uevent->resp.param.arg32, &event.param.arg,

	       sizeof(event.param.arg));



	mutex_lock(&ctx->file->mut);

	list_add_tail(&uevent->list, &ctx->file->event_list);

	mutex_unlock(&ctx->file->mut);

	wake_up_interruptible(&ctx->file->poll_wait);



out:

	ucma_put_ctx(ctx);

	return ret;

}



static ssize_t (*ucma_cmd_table[])(struct ucma_file *file,

				   const char __user *inbuf,

				   int in_len, int out_len) = {
@@ -1771,7 +1820,8 @@ static ssize_t (*ucma_cmd_table[])(struct ucma_file *file, 
	[RDMA_USER_CM_CMD_BIND]		 = ucma_bind,

	[RDMA_USER_CM_CMD_RESOLVE_ADDR]	 = ucma_resolve_addr,

	[RDMA_USER_CM_CMD_JOIN_MCAST]	 = ucma_join_multicast,

	[RDMA_USER_CM_CMD_RESOLVE_IB_SERVICE] = ucma_resolve_ib_service

	[RDMA_USER_CM_CMD_RESOLVE_IB_SERVICE] = ucma_resolve_ib_service,

	[RDMA_USER_CM_CMD_WRITE_CM_EVENT] = ucma_write_cm_event,

};



static ssize_t ucma_write(struct file *filp, const char __user *buf,

include/rdma/rdma_cm.h

+4 −1
Original line number Diff line number Diff line
@@ -35,7 +35,9 @@ enum rdma_cm_event_type { 
	RDMA_CM_EVENT_ADDR_CHANGE,

	RDMA_CM_EVENT_TIMEWAIT_EXIT,

	RDMA_CM_EVENT_ADDRINFO_RESOLVED,

	RDMA_CM_EVENT_ADDRINFO_ERROR

	RDMA_CM_EVENT_ADDRINFO_ERROR,

	RDMA_CM_EVENT_USER,

	RDMA_CM_EVENT_INTERNAL,

};



const char *__attribute_const__ rdma_event_msg(enum rdma_cm_event_type event);
@@ -98,6 +100,7 @@ struct rdma_cm_event { 
	union {

		struct rdma_conn_param	conn;

		struct rdma_ud_param	ud;

		u64			arg;

	} param;

	struct rdma_ucm_ece ece;

};

include/uapi/rdma/rdma_user_cm.h

+15 −1
Original line number Diff line number Diff line
@@ -68,7 +68,8 @@ enum { 
	RDMA_USER_CM_CMD_BIND,

	RDMA_USER_CM_CMD_RESOLVE_ADDR,

	RDMA_USER_CM_CMD_JOIN_MCAST,

	RDMA_USER_CM_CMD_RESOLVE_IB_SERVICE

	RDMA_USER_CM_CMD_RESOLVE_IB_SERVICE,

	RDMA_USER_CM_CMD_WRITE_CM_EVENT,

};



/* See IBTA Annex A11, servies ID bytes 4 & 5 */
@@ -304,6 +305,7 @@ struct rdma_ucm_event_resp { 
	union {

		struct rdma_ucm_conn_param conn;

		struct rdma_ucm_ud_param   ud;

		__u32 arg32[2];

	} param;

	__u32 reserved;

	struct rdma_ucm_ece ece;
@@ -362,4 +364,16 @@ struct rdma_ucm_resolve_ib_service { 
	__u32 id;

	struct rdma_ucm_ib_service ibs;

};



struct rdma_ucm_write_cm_event {

	__u32 id;

	__u32 reserved;

	__u32 event;

	__u32 status;

	union {

		struct rdma_ucm_conn_param conn;

		struct rdma_ucm_ud_param ud;

		__u64 arg;

	} param;

};

#endif /* RDMA_USER_CM_H */