vfio/mlx5: Create and destroy page tracker object

Add support for creating and destroying page tracker object.

This object is used to control/report the device dirty pages.

As part of creating the tracker need to consider the device capabilities
for max ranges and adapt/combine ranges accordingly.

Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-8-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/pci/mlx5/cmd.c

@@ -410,6 +410,148 @@ end:
 	return err;
 }
 
+static void combine_ranges(struct rb_root_cached *root, u32 cur_nodes,
+			   u32 req_nodes)
+{
+	struct interval_tree_node *prev, *curr, *comb_start, *comb_end;
+	unsigned long min_gap;
+	unsigned long curr_gap;
+
+	/* Special shortcut when a single range is required */
+	if (req_nodes == 1) {
+		unsigned long last;
+
+		curr = comb_start = interval_tree_iter_first(root, 0, ULONG_MAX);
+		while (curr) {
+			last = curr->last;
+			prev = curr;
+			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
+			if (prev != comb_start)
+				interval_tree_remove(prev, root);
+		}
+		comb_start->last = last;
+		return;
+	}
+
+	/* Combine ranges which have the smallest gap */
+	while (cur_nodes > req_nodes) {
+		prev = NULL;
+		min_gap = ULONG_MAX;
+		curr = interval_tree_iter_first(root, 0, ULONG_MAX);
+		while (curr) {
+			if (prev) {
+				curr_gap = curr->start - prev->last;
+				if (curr_gap < min_gap) {
+					min_gap = curr_gap;
+					comb_start = prev;
+					comb_end = curr;
+				}
+			}
+			prev = curr;
+			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);
+		}
+		comb_start->last = comb_end->last;
+		interval_tree_remove(comb_end, root);
+		cur_nodes--;
+	}
+}
+
+static int mlx5vf_create_tracker(struct mlx5_core_dev *mdev,
+				 struct mlx5vf_pci_core_device *mvdev,
+				 struct rb_root_cached *ranges, u32 nnodes)
+{
+	int max_num_range =
+		MLX5_CAP_ADV_VIRTUALIZATION(mdev, pg_track_max_num_range);
+	struct mlx5_vhca_page_tracker *tracker = &mvdev->tracker;
+	int record_size = MLX5_ST_SZ_BYTES(page_track_range);
+	u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)] = {};
+	struct interval_tree_node *node = NULL;
+	u64 total_ranges_len = 0;
+	u32 num_ranges = nnodes;
+	u8 log_addr_space_size;
+	void *range_list_ptr;
+	void *obj_context;
+	void *cmd_hdr;
+	int inlen;
+	void *in;
+	int err;
+	int i;
+
+	if (num_ranges > max_num_range) {
+		combine_ranges(ranges, nnodes, max_num_range);
+		num_ranges = max_num_range;
+	}
+
+	inlen = MLX5_ST_SZ_BYTES(create_page_track_obj_in) +
+				 record_size * num_ranges;
+	in = kzalloc(inlen, GFP_KERNEL);
+	if (!in)
+		return -ENOMEM;
+
+	cmd_hdr = MLX5_ADDR_OF(create_page_track_obj_in, in,
+			       general_obj_in_cmd_hdr);
+	MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, opcode,
+		 MLX5_CMD_OP_CREATE_GENERAL_OBJECT);
+	MLX5_SET(general_obj_in_cmd_hdr, cmd_hdr, obj_type,
+		 MLX5_OBJ_TYPE_PAGE_TRACK);
+	obj_context = MLX5_ADDR_OF(create_page_track_obj_in, in, obj_context);
+	MLX5_SET(page_track, obj_context, vhca_id, mvdev->vhca_id);
+	MLX5_SET(page_track, obj_context, track_type, 1);
+	MLX5_SET(page_track, obj_context, log_page_size,
+		 ilog2(tracker->host_qp->tracked_page_size));
+	MLX5_SET(page_track, obj_context, log_msg_size,
+		 ilog2(tracker->host_qp->max_msg_size));
+	MLX5_SET(page_track, obj_context, reporting_qpn, tracker->fw_qp->qpn);
+	MLX5_SET(page_track, obj_context, num_ranges, num_ranges);
+
+	range_list_ptr = MLX5_ADDR_OF(page_track, obj_context, track_range);
+	node = interval_tree_iter_first(ranges, 0, ULONG_MAX);
+	for (i = 0; i < num_ranges; i++) {
+		void *addr_range_i_base = range_list_ptr + record_size * i;
+		unsigned long length = node->last - node->start;
+
+		MLX5_SET64(page_track_range, addr_range_i_base, start_address,
+			   node->start);
+		MLX5_SET64(page_track_range, addr_range_i_base, length, length);
+		total_ranges_len += length;
+		node = interval_tree_iter_next(node, 0, ULONG_MAX);
+	}
+
+	WARN_ON(node);
+	log_addr_space_size = ilog2(total_ranges_len);
+	if (log_addr_space_size <
+	    (MLX5_CAP_ADV_VIRTUALIZATION(mdev, pg_track_log_min_addr_space)) ||
+	    log_addr_space_size >
+	    (MLX5_CAP_ADV_VIRTUALIZATION(mdev, pg_track_log_max_addr_space))) {
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
+	MLX5_SET(page_track, obj_context, log_addr_space_size,
+		 log_addr_space_size);
+	err = mlx5_cmd_exec(mdev, in, inlen, out, sizeof(out));
+	if (err)
+		goto out;
+
+	tracker->id = MLX5_GET(general_obj_out_cmd_hdr, out, obj_id);
+out:
+	kfree(in);
+	return err;
+}
+
+static int mlx5vf_cmd_destroy_tracker(struct mlx5_core_dev *mdev,
+				      u32 tracker_id)
+{
+	u32 in[MLX5_ST_SZ_DW(general_obj_in_cmd_hdr)] = {};
+	u32 out[MLX5_ST_SZ_DW(general_obj_out_cmd_hdr)] = {};
+
+	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_PAGE_TRACK);
+	MLX5_SET(general_obj_in_cmd_hdr, in, obj_id, tracker_id);
+
+	return mlx5_cmd_exec(mdev, in, sizeof(in), out, sizeof(out));
+}
+
 static int alloc_cq_frag_buf(struct mlx5_core_dev *mdev,
 			     struct mlx5_vhca_cq_buf *buf, int nent,
 			     int cqe_size)
@@ -833,6 +975,7 @@ _mlx5vf_free_page_tracker_resources(struct mlx5vf_pci_core_device *mvdev)
 
 	WARN_ON(mvdev->mdev_detach);
 
+	mlx5vf_cmd_destroy_tracker(mdev, tracker->id);
 	mlx5vf_destroy_qp(mdev, tracker->fw_qp);
 	mlx5vf_free_qp_recv_resources(mdev, tracker->host_qp);
 	mlx5vf_destroy_qp(mdev, tracker->host_qp);
@@ -941,6 +1084,10 @@ int mlx5vf_start_page_tracker(struct vfio_device *vdev,
 
 	tracker->host_qp = host_qp;
 	tracker->fw_qp = fw_qp;
+	err = mlx5vf_create_tracker(mdev, mvdev, ranges, nnodes);
+	if (err)
+		goto err_activate;
+
 	*page_size = host_qp->tracked_page_size;
 	mvdev->log_active = true;
 	mlx5vf_state_mutex_unlock(mvdev);

drivers/vfio/pci/mlx5/cmd.h

@@ -80,6 +80,7 @@ struct mlx5_vhca_qp {
 };
 
 struct mlx5_vhca_page_tracker {
+	u32 id;
 	u32 pdn;
 	struct mlx5_uars_page *uar;
 	struct mlx5_vhca_cq cq;