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From:   Eli Cohen <elic@nvidia.com>
To:     <mst@redhat.com>, <jasowang@redhat.com>,
        <virtualization@lists.linux-foundation.org>,
        <linux-kernel@vger.kernel.org>
CC:     <elic@nvidia.com>
Subject: [PATCH v1] vdpa/mlx5: Clear vq ready indication upon device reset
Date:   Thu, 3 Jun 2021 11:10:26 +0300
Message-ID: <20210603081026.5640-1-elic@nvidia.com>
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After device reset, the virtqueues are not ready so clear the ready
field.

Failing to do so can result in virtio_vdpa failing to load if the device
was previously used by vhost_vdpa and the old values are ready.
virtio_vdpa expects to find VQs in "not ready" state.

Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
Signed-off-by: Eli Cohen <elic@nvidia.com>
---
v0 --> v1:
  Make sure clear of ready is done only in reset flow

 drivers/vdpa/mlx5/net/mlx5_vnet.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 02a05492204c..eaeae67e0ff0 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -1766,6 +1766,14 @@ static void teardown_driver(struct mlx5_vdpa_net *ndev)
 	mutex_unlock(&ndev->reslock);
 }
 
+static void clear_vqs_ready(struct mlx5_vdpa_net *ndev)
+{
+	int i;
+
+	for (i = ndev->mvdev.max_vqs - 1; i >= 0; i--)
+		ndev->vqs[i].ready = false;
+}
+
 static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
 {
 	struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
@@ -1776,6 +1784,7 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
 	if (!status) {
 		mlx5_vdpa_info(mvdev, "performing device reset\n");
 		teardown_driver(ndev);
+		clear_vqs_ready(ndev);
 		mlx5_vdpa_destroy_mr(&ndev->mvdev);
 		ndev->mvdev.status = 0;
 		ndev->mvdev.mlx_features = 0;
-- 
2.31.1