[PATCH v3 rdma-next 7/7] RDMA/nldev: Expose whether RDMA monitoring is supported

[Michael Guralnik <michaelgur@nvidia.com>]

From: Chiara Meiohas <cmeiohas@nvidia.com>

Extend the "rdma sys" command to display whether RDMA
monitoring is supported.

RDMA monitoring is not supported in mlx4 because it does
not use the ib_device_set_netdev() API, which sends the
RDMA events.

Example output for kernel where monitoring is supported:
$ rdma sys show
netns shared privileged-qkey off monitor on copy-on-fork on

Example output for kernel where monitoring is not supported:
$ rdma sys show
netns shared privileged-qkey off monitor off copy-on-fork on

Signed-off-by: Chiara Meiohas <cmeiohas@nvidia.com>
Signed-off-by: Michael Guralnik <michaelgur@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/infiniband/core/nldev.c  | 6 ++++++
 include/uapi/rdma/rdma_netlink.h | 1 +
 2 files changed, 7 insertions(+)

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 30b0fd54a7d3..b2dca6aa531d 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -1952,6 +1952,12 @@ static int nldev_sys_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 		nlmsg_free(msg);
 		return err;
 	}
+
+	err = nla_put_u8(msg, RDMA_NLDEV_SYS_ATTR_MONITOR_MODE, 1);
+	if (err) {
+		nlmsg_free(msg);
+		return err;
+	}
 	/*
 	 * Copy-on-fork is supported.
 	 * See commits:
diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
index 5f9636d26050..39be09c0ffbb 100644
--- a/include/uapi/rdma/rdma_netlink.h
+++ b/include/uapi/rdma/rdma_netlink.h
@@ -579,6 +579,7 @@ enum rdma_nldev_attr {
 
 	RDMA_NLDEV_ATTR_EVENT_TYPE,		/* u8 */
 
+	RDMA_NLDEV_SYS_ATTR_MONITOR_MODE,	/* u8 */
 	/*
 	 * Always the end
 	 */
-- 
2.17.2