[PATCH rdma-next v3 7/7] RDMA/nldev: Provide detailed QP information

Leon Romanovsky
2018-01-11T15:31:32Z

From: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

Implement RDMA nldev netlink interface to get detailed
QP information.

Currently only dumpit variant is implemented.

Reviewed-by: Mark Bloch <markb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
drivers/infiniband/core/nldev.c | 228 +++++++++++++++++++++++++++++++++++++++
include/uapi/rdma/rdma_netlink.h | 45 ++++++++
2 files changed, 273 insertions(+)

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 952c95b776c9..8b243f222088 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -60,6 +60,18 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
.len = 16 },
[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_CURR] = { .type = NLA_U64 },
[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX] = { .type = NLA_U64 },
+ [RDMA_NLDEV_ATTR_RES_QP] = { .type = NLA_NESTED },
+ [RDMA_NLDEV_ATTR_RES_QP_ENTRY] = { .type = NLA_NESTED },
+ [RDMA_NLDEV_ATTR_RES_LQPN] = { .type = NLA_U32 },
+ [RDMA_NLDEV_ATTR_RES_RQPN] = { .type = NLA_U32 },
+ [RDMA_NLDEV_ATTR_RES_RQ_PSN] = { .type = NLA_U32 },
+ [RDMA_NLDEV_ATTR_RES_SQ_PSN] = { .type = NLA_U32 },
+ [RDMA_NLDEV_ATTR_RES_PATH_MIG_STATE] = { .type = NLA_U8 },
+ [RDMA_NLDEV_ATTR_RES_TYPE] = { .type = NLA_U8 },
+ [RDMA_NLDEV_ATTR_RES_STATE] = { .type = NLA_U8 },
+ [RDMA_NLDEV_ATTR_RES_PID] = { .type = NLA_U32 },
+ [RDMA_NLDEV_ATTR_RES_PID_COMM] = { .type = NLA_NUL_STRING,
+ .len = TASK_COMM_LEN },
};

static int fill_nldev_handle(struct sk_buff *msg, struct ib_device *device)
@@ -226,6 +238,78 @@ static int fill_res_info(struct sk_buff *msg, struct ib_device *device)
return ret;
}

+static int fill_res_qp_entry(struct sk_buff *msg,
+ struct ib_qp *qp, uint32_t port)
+{
+ struct rdma_restrack_entry *res = &qp->res;
+ struct ib_qp_init_attr qp_init_attr;
+ struct nlattr *entry_attr;
+ struct ib_qp_attr qp_attr;
+ int ret;
+
+ ret = ib_query_qp(qp, &qp_attr, 0, &qp_init_attr);
+ if (ret)
+ return ret;
+
+ if (port && port != qp_attr.port_num)
+ return 0;
+
+ entry_attr = nla_nest_start(msg, RDMA_NLDEV_ATTR_RES_QP_ENTRY);
+ if (!entry_attr)
+ goto out;
+
+ /* In create_qp() port is not set yet */
+ if (qp_attr.port_num &&
+ nla_put_u32(msg, RDMA_NLDEV_ATTR_PORT_INDEX, qp_attr.port_num))
+ goto err;
+
+ if (nla_put_u32(msg, RDMA_NLDEV_ATTR_RES_LQPN, qp->qp_num))
+ goto err;
+ if (qp->qp_type == IB_QPT_RC || qp->qp_type == IB_QPT_UC) {
+ if (nla_put_u32(msg, RDMA_NLDEV_ATTR_RES_RQPN,
+ qp_attr.dest_qp_num))
+ goto err;
+ if (nla_put_u32(msg, RDMA_NLDEV_ATTR_RES_RQ_PSN,
+ qp_attr.rq_psn))
+ goto err;
+ }
+
+ if (nla_put_u32(msg, RDMA_NLDEV_ATTR_RES_SQ_PSN, qp_attr.sq_psn))
+ goto err;
+
+ if (qp->qp_type == IB_QPT_RC || qp->qp_type == IB_QPT_UC ||
+ qp->qp_type == IB_QPT_XRC_INI || qp->qp_type == IB_QPT_XRC_TGT) {
+ if (nla_put_u8(msg, RDMA_NLDEV_ATTR_RES_PATH_MIG_STATE,
+ qp_attr.path_mig_state))
+ goto err;
+ }
+ if (nla_put_u8(msg, RDMA_NLDEV_ATTR_RES_TYPE, qp->qp_type))
+ goto err;
+ if (nla_put_u8(msg, RDMA_NLDEV_ATTR_RES_STATE, qp_attr.qp_state))
+ goto err;
+
+ /*
+ * Existence of task means that it is user QP and netlink
+ * user is invited to go and read /proc/PID/comm to get name
+ * of the task file and res->task_com should be NULL.
+ */
+ if (res->task &&
+ nla_put_u32(msg, RDMA_NLDEV_ATTR_RES_PID, task_pid_vnr(res->task)))
+ goto err;
+
+ if (res->task_comm &&
+ nla_put_string(msg, RDMA_NLDEV_ATTR_RES_PID_COMM, res->task_comm))
+ goto err;
+
+ nla_nest_end(msg, entry_attr);
+ return 0;
+
+err:
+ nla_nest_cancel(msg, entry_attr);
+out:
+ return -EMSGSIZE;
+}
+
static int nldev_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{
@@ -502,6 +586,137 @@ static int nldev_res_get_dumpit(struct sk_buff *skb,
return ib_enum_all_devs(_nldev_res_get_dumpit, skb, cb);
}

+static int nldev_res_get_qp_dumpit(struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ struct nlattr *tb[RDMA_NLDEV_ATTR_MAX];
+ struct rdma_restrack_entry *res, *nxt;
+ int err, ret, key, idx = 0;
+ struct nlattr *table_attr;
+ struct ib_device *device;
+ int start = cb->args[0];
+ struct nlmsghdr *nlh;
+ u32 index, port = 0;
+ struct ib_qp *qp;
+
+ err = nlmsg_parse(cb->nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
+ nldev_policy, NULL);
+ /*
+ * Right now, we are expecting the device index to get QP information,
+ * but it is possible to extend this code to return all devices in
+ * one shot by checking the existence of RDMA_NLDEV_ATTR_DEV_INDEX.
+ * if it doesn't exist, we will iterate over all devices.
+ *
+ * But it is not needed for now.
+ */
+ if (err || !tb[RDMA_NLDEV_ATTR_DEV_INDEX])
+ return -EINVAL;
+
+ index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
+ device = ib_device_get_by_index(index);
+ if (!device)
+ return -EINVAL;
+
+ /*
+ * If no PORT_INDEX is supplied, we will return QPs from whole device
+ */
+ if (tb[RDMA_NLDEV_ATTR_PORT_INDEX]) {
+ port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
+ if (!rdma_is_port_valid(device, port)) {
+ ret = -EINVAL;
+ goto err_index;
+ }
+ }
+
+ nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+ RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_RES_QP_GET),
+ 0, NLM_F_MULTI);
+
+ if (fill_nldev_handle(skb, device)) {
+ ret = -EMSGSIZE;
+ goto err;
+ }
+
+ table_attr = nla_nest_start(skb, RDMA_NLDEV_ATTR_RES_QP);
+ if (!table_attr) {
+ ret = -EMSGSIZE;
+ goto err;
+ }
+
+ rdma_restrack_lock(&device->res, RDMA_RESTRACK_QP);
+ for_each_res_safe(res, nxt, RDMA_RESTRACK_QP, device) {
+ if (idx < start) {
+ idx++;
+ continue;
+ }
+
+ key = srcu_read_lock(&res->srcu);
+
+ if ((!res->task && task_active_pid_ns(current) != &init_pid_ns) ||
+ (res->task &&
+ task_active_pid_ns(current) != task_active_pid_ns(res->task))) {
+ srcu_read_unlock(&res->srcu, key);
+ /*
+ * 1. Kernel QPs should be visible in init namsapce only
+ * 2. Preent only QPs visible in the current namespace
+ */
+ continue;
+ }
+
+ qp = container_of(res, struct ib_qp, res);
+ /*
+ * We are releasing the object list lock to ensure that
+ * object creation/destroy doesn't can progress while
+ * we are getting information about QP.
+ *
+ * It is needed to prevent writer starvation, because of
+ * large number of reources in object list.
+ */
+ rdma_restrack_unlock(&device->res, RDMA_RESTRACK_QP);
+ ret = fill_res_qp_entry(skb, qp, port);
+ rdma_restrack_lock(&device->res, RDMA_RESTRACK_QP);
+
+ /*
+ * There is a need to ensure that next QP is valid,
+ * because we dropped the lock protecting our linked list.
+ *
+ * The RCU protection of "res" ensures that it is safe.
+ */
+ list_safe_reset_next(res, nxt, list);
+
+ srcu_read_unlock(&res->srcu, key);
+
+ if (ret == -EMSGSIZE)
+ /*
+ * There is a chance to optimize here.
+ * It can be done by using list_prepare_entry
+ * and list_for_each_entry_continue afterwards.
+ */
+ break;
+ if (ret)
+ goto res_err;
+ idx++;
+ }
+ rdma_restrack_unlock(&device->res, RDMA_RESTRACK_QP);
+
+ nla_nest_end(skb, table_attr);
+ nlmsg_end(skb, nlh);
+ cb->args[0] = idx;
+ put_device(&device->dev);
+ return 0;
+
+res_err:
+ nla_nest_cancel(skb, table_attr);
+ rdma_restrack_unlock(&device->res, RDMA_RESTRACK_QP);
+
+err:
+ nlmsg_cancel(skb, nlh);
+
+err_index:
+ put_device(&device->dev);
+ return ret;
+}
+
static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
[RDMA_NLDEV_CMD_GET] = {
.doit = nldev_get_doit,
@@ -515,6 +730,19 @@ static const struct rdma_nl_cbs nldev_cb_table[RDMA_NLDEV_NUM_OPS] = {
.doit = nldev_res_get_doit,
.dump = nldev_res_get_dumpit,
},
+ [RDMA_NLDEV_CMD_RES_QP_GET] = {
+ .dump = nldev_res_get_qp_dumpit,
+ /*
+ * .doit is not implemented yet for two reasons:
+ * 1. It is not needed yet.
+ * 2. There is a need to provide identifier, while it is easy
+ * for the QPs (device index + port index + LQPN), it is not
+ * the case for the rest of resources (PD and CQ). Because it
+ * is better to provide similar interface for all resources,
+ * let's wait till we will have other resources implemented
+ * too.
+ */
+ },
};

void __init nldev_init(void)
diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
index e041d2eca4b8..b4fc354bea43 100644
--- a/include/uapi/rdma/rdma_netlink.h
+++ b/include/uapi/rdma/rdma_netlink.h
@@ -241,6 +241,11 @@ enum rdma_nldev_command {
RDMA_NLDEV_CMD_RES_NEW,
RDMA_NLDEV_CMD_RES_DEL,

+ RDMA_NLDEV_CMD_RES_QP_GET, /* can dump */
+ RDMA_NLDEV_CMD_RES_QP_SET,
+ RDMA_NLDEV_CMD_RES_QP_NEW,
+ RDMA_NLDEV_CMD_RES_QP_DEL,
+
RDMA_NLDEV_NUM_OPS
};

@@ -314,6 +319,46 @@ enum rdma_nldev_attr {
RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_CURR, /* u64 */
RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX, /* u64 */

+ RDMA_NLDEV_ATTR_RES_QP, /* nested table */
+ RDMA_NLDEV_ATTR_RES_QP_ENTRY, /* nested table */
+ /*
+ * Local QPN
+ */
+ RDMA_NLDEV_ATTR_RES_LQPN, /* u32 */
+ /*
+ * Remote QPN,
+ * Applicable for RC and UC only IBTA 11.2.5.3 QUERY QUEUE PAIR
+ */
+ RDMA_NLDEV_ATTR_RES_RQPN, /* u32 */
+ /*
+ * Receive Queue PSN,
+ * Applicable for RC and UC only 11.2.5.3 QUERY QUEUE PAIR
+ */
+ RDMA_NLDEV_ATTR_RES_RQ_PSN, /* u32 */
+ /*
+ * Send Queue PSN
+ */
+ RDMA_NLDEV_ATTR_RES_SQ_PSN, /* u32 */
+ RDMA_NLDEV_ATTR_RES_PATH_MIG_STATE, /* u8 */
+ /*
+ * QP types as visible to RDMA/core, the reserved QPT
+ * are not exported through this interface.
+ */
+ RDMA_NLDEV_ATTR_RES_TYPE, /* u8 */
+ RDMA_NLDEV_ATTR_RES_STATE, /* u8 */
+ /*
+ * Process ID which created object,
+ * in case of kernel origin, PID won't exist.
+ */
+ RDMA_NLDEV_ATTR_RES_PID, /* u32 */
+ /*
+ * The name of process created following resource.
+ * It will exist only for kernel objects.
+ * For user created objects, the user is supposed
+ * to read /proc/PID/comm file.
+ */
+ RDMA_NLDEV_ATTR_RES_PID_COMM, /* string */
+
RDMA_NLDEV_ATTR_MAX
};
#endif /* _UAPI_RDMA_NETLINK_H */
--
2.15.1