IB/uverbs: Expose UAPI to query ucontext

Expose UAPI to query ucontext, this will let user space application that
didn't allocate the ucontext but has access to by owning the matching
command FD to retrieve the ucontext information.

Link: https://lore.kernel.org/r/20200630093916.332097-4-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

4 files changed, 51 insertions, 1 deletions

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 40cf07129f66..1900c0df3c8a 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2674,6 +2674,7 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
 	SET_DEVICE_OP(dev_ops, query_port);
 	SET_DEVICE_OP(dev_ops, query_qp);
 	SET_DEVICE_OP(dev_ops, query_srq);
+	SET_DEVICE_OP(dev_ops, query_ucontext);
 	SET_DEVICE_OP(dev_ops, rdma_netdev_get_params);
 	SET_DEVICE_OP(dev_ops, read_counters);
 	SET_DEVICE_OP(dev_ops, reg_dm_mr);
diff --git a/drivers/infiniband/core/uverbs_std_types_device.c b/drivers/infiniband/core/uverbs_std_types_device.c
index ae4a59d6f9b1..8e58605a17be 100644
--- a/drivers/infiniband/core/uverbs_std_types_device.c
+++ b/drivers/infiniband/core/uverbs_std_types_device.c
@@ -229,6 +229,37 @@ static int UVERBS_HANDLER(UVERBS_METHOD_GET_CONTEXT)(
 	return 0;
 }
 
+static int UVERBS_HANDLER(UVERBS_METHOD_QUERY_CONTEXT)(
+	struct uverbs_attr_bundle *attrs)
+{
+	u64 core_support = IB_UVERBS_CORE_SUPPORT_OPTIONAL_MR_ACCESS;
+	struct ib_ucontext *ucontext;
+	struct ib_device *ib_dev;
+	u32 num_comp;
+	int ret;
+
+	ucontext = ib_uverbs_get_ucontext(attrs);
+	if (IS_ERR(ucontext))
+		return PTR_ERR(ucontext);
+	ib_dev = ucontext->device;
+
+	if (!ib_dev->ops.query_ucontext)
+		return -EOPNOTSUPP;
+
+	num_comp = attrs->ufile->device->num_comp_vectors;
+	ret = uverbs_copy_to(attrs, UVERBS_ATTR_QUERY_CONTEXT_NUM_COMP_VECTORS,
+			     &num_comp, sizeof(num_comp));
+	if (IS_UVERBS_COPY_ERR(ret))
+		return ret;
+
+	ret = uverbs_copy_to(attrs, UVERBS_ATTR_QUERY_CONTEXT_CORE_SUPPORT,
+			     &core_support, sizeof(core_support));
+	if (IS_UVERBS_COPY_ERR(ret))
+		return ret;
+
+	return ucontext->device->ops.query_ucontext(ucontext, attrs);
+}
+
 DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_METHOD_GET_CONTEXT,
 	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_GET_CONTEXT_NUM_COMP_VECTORS,
@@ -238,6 +269,13 @@ DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_ATTR_UHW());
 
 DECLARE_UVERBS_NAMED_METHOD(
+	UVERBS_METHOD_QUERY_CONTEXT,
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_QUERY_CONTEXT_NUM_COMP_VECTORS,
+			    UVERBS_ATTR_TYPE(u32), UA_OPTIONAL),
+	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_QUERY_CONTEXT_CORE_SUPPORT,
+			    UVERBS_ATTR_TYPE(u64), UA_OPTIONAL));
+
+DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_METHOD_INFO_HANDLES,
 	/* Also includes any device specific object ids */
 	UVERBS_ATTR_CONST_IN(UVERBS_ATTR_INFO_OBJECT_ID,
@@ -260,7 +298,8 @@ DECLARE_UVERBS_GLOBAL_METHODS(UVERBS_OBJECT_DEVICE,
 			      &UVERBS_METHOD(UVERBS_METHOD_GET_CONTEXT),
 			      &UVERBS_METHOD(UVERBS_METHOD_INVOKE_WRITE),
 			      &UVERBS_METHOD(UVERBS_METHOD_INFO_HANDLES),
-			      &UVERBS_METHOD(UVERBS_METHOD_QUERY_PORT));
+			      &UVERBS_METHOD(UVERBS_METHOD_QUERY_PORT),
+			      &UVERBS_METHOD(UVERBS_METHOD_QUERY_CONTEXT));
 
 const struct uapi_definition uverbs_def_obj_device[] = {
 	UAPI_DEF_CHAIN_OBJ_TREE_NAMED(UVERBS_OBJECT_DEVICE),
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 20c801730fed..6c72bb194148 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2645,6 +2645,10 @@ struct ib_device_ops {
 	 */
 	int (*fill_stat_mr_entry)(struct sk_buff *msg, struct ib_mr *ibmr);
 
+	/* query driver for its ucontext properties */
+	int (*query_ucontext)(struct ib_ucontext *context,
+			      struct uverbs_attr_bundle *attrs);
+
 	DECLARE_RDMA_OBJ_SIZE(ib_ah);
 	DECLARE_RDMA_OBJ_SIZE(ib_cq);
 	DECLARE_RDMA_OBJ_SIZE(ib_pd);
diff --git a/include/uapi/rdma/ib_user_ioctl_cmds.h b/include/uapi/rdma/ib_user_ioctl_cmds.h
index 4961d5e858eb..83b6e71ea216 100644
--- a/include/uapi/rdma/ib_user_ioctl_cmds.h
+++ b/include/uapi/rdma/ib_user_ioctl_cmds.h
@@ -69,6 +69,7 @@ enum uverbs_methods_device {
 	UVERBS_METHOD_INFO_HANDLES,
 	UVERBS_METHOD_QUERY_PORT,
 	UVERBS_METHOD_GET_CONTEXT,
+	UVERBS_METHOD_QUERY_CONTEXT,
 };
 
 enum uverbs_attrs_invoke_write_cmd_attr_ids {
@@ -87,6 +88,11 @@ enum uverbs_attrs_get_context_attr_ids {
 	UVERBS_ATTR_GET_CONTEXT_CORE_SUPPORT,
 };
 
+enum uverbs_attrs_query_context_attr_ids {
+	UVERBS_ATTR_QUERY_CONTEXT_NUM_COMP_VECTORS,
+	UVERBS_ATTR_QUERY_CONTEXT_CORE_SUPPORT,
+};
+
 enum uverbs_attrs_create_cq_cmd_attr_ids {
 	UVERBS_ATTR_CREATE_CQ_HANDLE,
 	UVERBS_ATTR_CREATE_CQ_CQE,