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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Eli Cohen <elic@nvidia.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15 115/167] vdpa/mlx5: Initialize CVQ vringh only once
Date:   Tue, 19 Jul 2022 13:54:07 +0200
Message-Id: <20220719114707.667896153@linuxfoundation.org>
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From: Eli Cohen <elic@nvidia.com>

[ Upstream commit ace9252446ec615cd79a5f77d90edb25c0b9d024 ]

Currently, CVQ vringh is initialized inside setup_virtqueues() which is
called every time a memory update is done. This is undesirable since it
resets all the context of the vring, including the available and used
indices.

Move the initialization to mlx5_vdpa_set_status() when
VIRTIO_CONFIG_S_DRIVER_OK is set.

Signed-off-by: Eli Cohen <elic@nvidia.com>
Message-Id: <20220613075958.511064-2-elic@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/vdpa/mlx5/net/mlx5_vnet.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 467a349dc26c..e748c00789f0 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1898,7 +1898,6 @@ static int verify_driver_features(struct mlx5_vdpa_dev *mvdev, u64 features)
 static int setup_virtqueues(struct mlx5_vdpa_dev *mvdev)
 {
 	struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
-	struct mlx5_control_vq *cvq = &mvdev->cvq;
 	int err;
 	int i;
 
@@ -1908,16 +1907,6 @@ static int setup_virtqueues(struct mlx5_vdpa_dev *mvdev)
 			goto err_vq;
 	}
 
-	if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ)) {
-		err = vringh_init_iotlb(&cvq->vring, mvdev->actual_features,
-					MLX5_CVQ_MAX_ENT, false,
-					(struct vring_desc *)(uintptr_t)cvq->desc_addr,
-					(struct vring_avail *)(uintptr_t)cvq->driver_addr,
-					(struct vring_used *)(uintptr_t)cvq->device_addr);
-		if (err)
-			goto err_vq;
-	}
-
 	return 0;
 
 err_vq:
@@ -2184,6 +2173,21 @@ static void clear_vqs_ready(struct mlx5_vdpa_net *ndev)
 	ndev->mvdev.cvq.ready = false;
 }
 
+static int setup_cvq_vring(struct mlx5_vdpa_dev *mvdev)
+{
+	struct mlx5_control_vq *cvq = &mvdev->cvq;
+	int err = 0;
+
+	if (mvdev->actual_features & BIT_ULL(VIRTIO_NET_F_CTRL_VQ))
+		err = vringh_init_iotlb(&cvq->vring, mvdev->actual_features,
+					MLX5_CVQ_MAX_ENT, false,
+					(struct vring_desc *)(uintptr_t)cvq->desc_addr,
+					(struct vring_avail *)(uintptr_t)cvq->driver_addr,
+					(struct vring_used *)(uintptr_t)cvq->device_addr);
+
+	return err;
+}
+
 static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
 {
 	struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
@@ -2194,6 +2198,11 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
 
 	if ((status ^ ndev->mvdev.status) & VIRTIO_CONFIG_S_DRIVER_OK) {
 		if (status & VIRTIO_CONFIG_S_DRIVER_OK) {
+			err = setup_cvq_vring(mvdev);
+			if (err) {
+				mlx5_vdpa_warn(mvdev, "failed to setup control VQ vring\n");
+				goto err_setup;
+			}
 			err = setup_driver(mvdev);
 			if (err) {
 				mlx5_vdpa_warn(mvdev, "failed to setup driver\n");
-- 
2.35.1