From: Yishai Hadas <yishaih@mellanox.com>
Date: Sun, 17 Jun 2018 12:59:57 +0300
Subject: IB/mlx5: Introduce DEVX
Patch-mainline: v4.19-rc1
Git-commit: a8b92ca1b0e5ce620e425e9d2f89ce44f1a82a82
References: bsc#1103991 FATE#326007

Introduce DEVX to enable direct device commands in downstream patches
from this series.

In that mode of work the firmware manages the isolation between
processes' resources and as such a DEVX user id is created and assigned
to the given user context upon allocation request.

A capability check is done to make sure that this feature is really
supported by the firmware prior to creating the DEVX user id.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/mlx5/Makefile  |    1 
 drivers/infiniband/hw/mlx5/devx.c    |   58 +++++++++++++++++++++++++++++++++++
 drivers/infiniband/hw/mlx5/main.c    |   24 ++++++++++++--
 drivers/infiniband/hw/mlx5/mlx5_ib.h |   13 +++++++
 include/uapi/rdma/mlx5-abi.h         |    3 +
 5 files changed, 96 insertions(+), 3 deletions(-)
 create mode 100644 drivers/infiniband/hw/mlx5/devx.c

--- a/drivers/infiniband/hw/mlx5/Makefile
+++ b/drivers/infiniband/hw/mlx5/Makefile
@@ -3,3 +3,4 @@ obj-$(CONFIG_MLX5_INFINIBAND)	+= mlx5_ib
 mlx5_ib-y :=	main.o cq.o doorbell.o qp.o mem.o srq.o mr.o ah.o mad.o gsi.o ib_virt.o cmd.o cong.o
 mlx5_ib-$(CONFIG_INFINIBAND_ON_DEMAND_PAGING) += odp.o
 mlx5_ib-$(CONFIG_MLX5_ESWITCH) += ib_rep.o
+mlx5_ib-$(CONFIG_INFINIBAND_USER_ACCESS) += devx.o
--- /dev/null
+++ b/drivers/infiniband/hw/mlx5/devx.c
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/*
+ * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
+ */
+
+#include <rdma/ib_user_verbs.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/uverbs_types.h>
+#include <rdma/uverbs_ioctl.h>
+#include <rdma/mlx5_user_ioctl_cmds.h>
+#include <rdma/ib_umem.h>
+#include <linux/mlx5/driver.h>
+#include <linux/mlx5/fs.h>
+#include "mlx5_ib.h"
+
+int mlx5_ib_devx_create(struct mlx5_ib_dev *dev, struct mlx5_ib_ucontext *context)
+{
+	u32 in[MLX5_ST_SZ_DW(create_uctx_in)] = {0};
+	u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)] = {0};
+	u64 general_obj_types;
+	void *uctx;
+	void *hdr;
+	int err;
+
+	uctx = MLX5_ADDR_OF(create_uctx_in, in, uctx);
+	hdr = MLX5_ADDR_OF(create_uctx_in, in, hdr);
+
+	general_obj_types = MLX5_CAP_GEN_64(dev->mdev, general_obj_types);
+	if (!(general_obj_types & MLX5_GENERAL_OBJ_TYPES_CAP_UCTX) ||
+	    !(general_obj_types & MLX5_GENERAL_OBJ_TYPES_CAP_UMEM))
+		return -EINVAL;
+
+	if (!capable(CAP_NET_RAW))
+		return -EPERM;
+
+	MLX5_SET(general_obj_in_cmd_hdr, hdr, opcode, MLX5_CMD_OP_CREATE_GENERAL_OBJECT);
+	MLX5_SET(general_obj_in_cmd_hdr, hdr, obj_type, MLX5_OBJ_TYPE_UCTX);
+
+	err = mlx5_cmd_exec(dev->mdev, in, sizeof(in), out, sizeof(out));
+	if (err)
+		return err;
+
+	context->devx_uid = MLX5_GET(general_obj_out_cmd_hdr, out, obj_id);
+	return 0;
+}
+
+void mlx5_ib_devx_destroy(struct mlx5_ib_dev *dev,
+			  struct mlx5_ib_ucontext *context)
+{
+	u32 in[MLX5_ST_SZ_DW(general_obj_in_cmd_hdr)] = {0};
+	u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)] = {0};
+
+	MLX5_SET(general_obj_in_cmd_hdr, in, opcode, MLX5_CMD_OP_DESTROY_GENERAL_OBJECT);
+	MLX5_SET(general_obj_in_cmd_hdr, in, obj_type, MLX5_OBJ_TYPE_UCTX);
+	MLX5_SET(general_obj_in_cmd_hdr, in, obj_id, context->devx_uid);
+
+	mlx5_cmd_exec(dev->mdev, in, sizeof(in), out, sizeof(out));
+}
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1649,8 +1649,8 @@ static struct ib_ucontext *mlx5_ib_alloc
 	if (err)
 		return ERR_PTR(err);
 
-	if (req.flags)
-		return ERR_PTR(-EINVAL);
+	if (req.flags & ~MLX5_IB_ALLOC_UCTX_DEVX)
+		return ERR_PTR(-EOPNOTSUPP);
 
 	if (req.comp_mask || req.reserved0 || req.reserved1 || req.reserved2)
 		return ERR_PTR(-EOPNOTSUPP);
@@ -1734,6 +1734,18 @@ static struct ib_ucontext *mlx5_ib_alloc
 			goto out_uars;
 	}
 
+	if (req.flags & MLX5_IB_ALLOC_UCTX_DEVX) {
+		/* Block DEVX on Infiniband as of SELinux */
+		if (mlx5_ib_port_link_layer(ibdev, 1) != IB_LINK_LAYER_ETHERNET) {
+			err = -EPERM;
+			goto out_td;
+		}
+
+		err = mlx5_ib_devx_create(dev, context);
+		if (err)
+			goto out_td;
+	}
+
 	INIT_LIST_HEAD(&context->vma_private_list);
 	mutex_init(&context->vma_private_list_mutex);
 	INIT_LIST_HEAD(&context->db_page_list);
@@ -1794,7 +1806,7 @@ static struct ib_ucontext *mlx5_ib_alloc
 
 	err = ib_copy_to_udata(udata, &resp, resp.response_length);
 	if (err)
-		goto out_td;
+		goto out_mdev;
 
 	bfregi->ver = ver;
 	bfregi->num_low_latency_bfregs = req.num_low_latency_bfregs;
@@ -1804,6 +1816,9 @@ static struct ib_ucontext *mlx5_ib_alloc
 
 	return &context->ibucontext;
 
+out_mdev:
+	if (req.flags & MLX5_IB_ALLOC_UCTX_DEVX)
+		mlx5_ib_devx_destroy(dev, context);
 out_td:
 	if (MLX5_CAP_GEN(dev->mdev, log_max_transport_domain))
 		mlx5_ib_dealloc_transport_domain(dev, context->tdn);
@@ -1829,6 +1844,9 @@ static int mlx5_ib_dealloc_ucontext(stru
 	struct mlx5_ib_dev *dev = to_mdev(ibcontext->device);
 	struct mlx5_bfreg_info *bfregi;
 
+	if (context->devx_uid)
+		mlx5_ib_devx_destroy(dev, context);
+
 	bfregi = &context->bfregi;
 	if (MLX5_CAP_GEN(dev->mdev, log_max_transport_domain))
 		mlx5_ib_dealloc_transport_domain(dev, context->tdn);
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -143,6 +143,7 @@ struct mlx5_ib_ucontext {
 
 	u64			lib_caps;
 	DECLARE_BITMAP(dm_pages, MLX5_MAX_MEMIC_PAGES);
+	u16			devx_uid;
 };
 
 static inline struct mlx5_ib_ucontext *to_mucontext(struct ib_ucontext *ibucontext)
@@ -1215,6 +1216,18 @@ struct mlx5_core_dev *mlx5_ib_get_native
 void mlx5_ib_put_native_port_mdev(struct mlx5_ib_dev *dev,
 				  u8 port_num);
 
+#if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
+int mlx5_ib_devx_create(struct mlx5_ib_dev *dev,
+			struct mlx5_ib_ucontext *context);
+void mlx5_ib_devx_destroy(struct mlx5_ib_dev *dev,
+			  struct mlx5_ib_ucontext *context);
+#else
+static inline int
+mlx5_ib_devx_create(struct mlx5_ib_dev *dev,
+		    struct mlx5_ib_ucontext *context) { return -EOPNOTSUPP; };
+static inline void mlx5_ib_devx_destroy(struct mlx5_ib_dev *dev,
+					struct mlx5_ib_ucontext *context) {}
+#endif
 static inline void init_query_mad(struct ib_smp *mad)
 {
 	mad->base_version  = 1;
--- a/include/uapi/rdma/mlx5-abi.h
+++ b/include/uapi/rdma/mlx5-abi.h
@@ -75,6 +75,9 @@ enum mlx5_lib_caps {
 	MLX5_LIB_CAP_4K_UAR	= (__u64)1 << 0,
 };
 
+enum mlx5_ib_alloc_uctx_v2_flags {
+	MLX5_IB_ALLOC_UCTX_DEVX	= 1 << 0,
+};
 struct mlx5_ib_alloc_ucontext_req_v2 {
 	__u32	total_num_bfregs;
 	__u32	num_low_latency_bfregs;