RDMA/nldev: Add support to add/delete a sub IB device through netlink

Add new netlink commands and attributes to support adding and deleting
a sub IB device with admin privilege.

Examples:
$ rdma dev add smi1 type SMI parent ibp8s0f1
$ rdma dev del smi1

Signed-off-by: Mark Zhang <[email protected]>
Link: https://lore.kernel.org/r/77cbf1b36359642be8a8d8c5c2f4e585b544282f.1718553901.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <[email protected]>

Author: MarkZhang81

drivers/infiniband/core/nldev.c

@@ -167,6 +167,7 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
 	[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC] = { .type = NLA_U8 },
 	[RDMA_NLDEV_SYS_ATTR_PRIVILEGED_QKEY_MODE] = { .type = NLA_U8 },
 	[RDMA_NLDEV_ATTR_DRIVER_DETAILS]	= { .type = NLA_U8 },
+	[RDMA_NLDEV_ATTR_DEV_TYPE]		= { .type = NLA_U8 },
 };
 
 static int put_driver_name_print_type(struct sk_buff *msg, const char *name,
@@ -2548,6 +2549,56 @@ static int nldev_stat_get_counter_status_doit(struct sk_buff *skb,
 	return ret;
 }
 
+static int nldev_newdev(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
+	enum rdma_nl_dev_type type;
+	struct ib_device *parent;
+	char name[IFNAMSIZ] = {};
+	u32 parentid;
+	int ret;
+
+	ret = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
+			  nldev_policy, extack);
+	if (ret || !tb[RDMA_NLDEV_ATTR_DEV_INDEX] ||
+		!tb[RDMA_NLDEV_ATTR_DEV_NAME] || !tb[RDMA_NLDEV_ATTR_DEV_TYPE])
+		return -EINVAL;
+
+	nla_strscpy(name, tb[RDMA_NLDEV_ATTR_DEV_NAME], sizeof(name));
+	type = nla_get_u8(tb[RDMA_NLDEV_ATTR_DEV_TYPE]);
+	parentid = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
+	parent = ib_device_get_by_index(sock_net(skb->sk), parentid);
+	if (!parent)
+		return -EINVAL;
+
+	ret = ib_add_sub_device(parent, type, name);
+	ib_device_put(parent);
+
+	return ret;
+}
+
+static int nldev_deldev(struct sk_buff *skb, struct nlmsghdr *nlh,
+			struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
+	struct ib_device *device;
+	u32 devid;
+	int ret;
+
+	ret = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
+			  nldev_policy, extack);
+	if (ret || !tb[RDMA_NLDEV_ATTR_DEV_INDEX])
+		return -EINVAL;
+
+	devid = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
+	device = ib_device_get_by_index(sock_net(skb->sk), devid);
+	if (!device)
+		return -EINVAL;
+
+	return ib_del_sub_device_and_put(device);
+}
+
 static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
 	[RDMA_NLDEV_CMD_GET] = {
 		.doit = nldev_get_doit,
@@ -2646,6 +2697,14 @@ static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
 	[RDMA_NLDEV_CMD_STAT_GET_STATUS] = {
 		.doit = nldev_stat_get_counter_status_doit,
 	},
+	[RDMA_NLDEV_CMD_NEWDEV] = {
+		.doit = nldev_newdev,
+		.flags = RDMA_NL_ADMIN_PERM,
+	},
+	[RDMA_NLDEV_CMD_DELDEV] = {
+		.doit = nldev_deldev,
+		.flags = RDMA_NL_ADMIN_PERM,
+	},
 };
 
 void __init nldev_init(void)

include/uapi/rdma/rdma_netlink.h

@@ -301,6 +301,10 @@ enum rdma_nldev_command {
 
 	RDMA_NLDEV_CMD_RES_SRQ_GET_RAW,
 
+	RDMA_NLDEV_CMD_NEWDEV,
+
+	RDMA_NLDEV_CMD_DELDEV,
+
 	RDMA_NLDEV_NUM_OPS
 };
 
@@ -564,6 +568,8 @@ enum rdma_nldev_attr {
 	 */
 	RDMA_NLDEV_ATTR_RES_SUBTYPE,		/* string */
 
+	RDMA_NLDEV_ATTR_DEV_TYPE,		/* u8 */
+
 	/*
 	 * Always the end
 	 */