From: Eli Cohen <elic@nvidia.com>
Date: Wed, 5 Jan 2022 13:46:34 +0200
Subject: vdpa/mlx5: Distribute RX virtqueues in RQT object
Patch-mainline: v5.17-rc1
Git-commit: a7f46ba42485394edf9836969e220878f4908465
References: jsc#PED-1549

Distribute the available rx virtqueues amongst the available RQT
entries.

RQTs require to have a power of two entries. When creating or modifying
the RQT, use the lowest number of power of two entries that is not less
than the number of rx virtqueues. Distribute them in the available
entries such that some virtqueus may be referenced twice.

This allows to configure any number of virtqueue pairs when multiqueue
is used.

Reviewed-by: Si-Wei Liu <si-wei.liu@oracle.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20220105114646.577224-3-elic@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/vdpa/mlx5/net/mlx5_vnet.c |   32 ++++++++------------------------
 1 file changed, 8 insertions(+), 24 deletions(-)

--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1259,17 +1259,10 @@ static int create_rqt(struct mlx5_vdpa_n
 	MLX5_SET(rqtc, rqtc, list_q_type, MLX5_RQTC_LIST_Q_TYPE_VIRTIO_NET_Q);
 	MLX5_SET(rqtc, rqtc, rqt_max_size, max_rqt);
 	list = MLX5_ADDR_OF(rqtc, rqtc, rq_num[0]);
-	for (i = 0, j = 0; j < max_rqt; j++) {
-		if (!ndev->vqs[j].initialized)
-			continue;
-
-		if (!vq_is_tx(ndev->vqs[j].index)) {
-			list[i] = cpu_to_be32(ndev->vqs[j].virtq_id);
-			i++;
-		}
-	}
-	MLX5_SET(rqtc, rqtc, rqt_actual_size, i);
+	for (i = 0, j = 0; i < max_rqt; i++, j += 2)
+		list[i] = cpu_to_be32(ndev->vqs[j % ndev->mvdev.max_vqs].virtq_id);
 
+	MLX5_SET(rqtc, rqtc, rqt_actual_size, max_rqt);
 	err = mlx5_vdpa_create_rqt(&ndev->mvdev, in, inlen, &ndev->res.rqtn);
 	kfree(in);
 	if (err)
@@ -1290,7 +1283,7 @@ static int modify_rqt(struct mlx5_vdpa_n
 	int i, j;
 	int err;
 
-	max_rqt = min_t(int, ndev->cur_num_vqs / 2,
+	max_rqt = min_t(int, roundup_pow_of_two(ndev->cur_num_vqs / 2),
 			1 << MLX5_CAP_GEN(ndev->mvdev.mdev, log_max_rqt_size));
 	if (max_rqt < 1)
 		return -EOPNOTSUPP;
@@ -1306,16 +1299,10 @@ static int modify_rqt(struct mlx5_vdpa_n
 	MLX5_SET(rqtc, rqtc, list_q_type, MLX5_RQTC_LIST_Q_TYPE_VIRTIO_NET_Q);
 
 	list = MLX5_ADDR_OF(rqtc, rqtc, rq_num[0]);
-	for (i = 0, j = 0; j < num; j++) {
-		if (!ndev->vqs[j].initialized)
-			continue;
-
-		if (!vq_is_tx(ndev->vqs[j].index)) {
-			list[i] = cpu_to_be32(ndev->vqs[j].virtq_id);
-			i++;
-		}
-	}
-	MLX5_SET(rqtc, rqtc, rqt_actual_size, i);
+	for (i = 0, j = 0; i < max_rqt; i++, j += 2)
+		list[i] = cpu_to_be32(ndev->vqs[j % num].virtq_id);
+
+	MLX5_SET(rqtc, rqtc, rqt_actual_size, max_rqt);
 	err = mlx5_vdpa_modify_rqt(&ndev->mvdev, in, inlen, ndev->res.rqtn);
 	kfree(in);
 	if (err)
@@ -1579,9 +1566,6 @@ static virtio_net_ctrl_ack handle_ctrl_m
 			break;
 		}
 
-		if (newqps & (newqps - 1))
-			break;
-
 		if (!change_num_qps(mvdev, newqps))
 			status = VIRTIO_NET_OK;