mlx5_vdpa_dev_add() doesn’t initialize mvdev->actual_features. It’s
initialized later by mlx5_vdpa_set_driver_features(). However,
mlx5_vdpa_get_config() depends on the VIRTIO_F_VERSION_1 flag in
actual_features, to return data with correct endianness. When it’s called
before mlx5_vdpa_set_driver_features(), the data are incorrectly returned
as big-endian on big-endian machines, while QEMU then interprets them as
little-endian.
The fix is to initialize this VIRTIO_F_VERSION_1 as early as possible,
especially considering that mlx5_vdpa_dev_add() insists on this flag to
always be set anyway.
Signed-off-by: Konstantin Shkolnyy <k...@linux.ibm.com>
---
Changes in V2: Initialize only VIRTIO_F_VERSION_1 in actual_features,
rather than all flags.
drivers/vdpa/mlx5/net/mlx5_vnet.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 36099047560d..cccc49a08a1a 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -3884,6 +3884,9 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev
*v_mdev, const char *name,
ndev->mvdev.max_vqs = max_vqs;
mvdev = &ndev->mvdev;
mvdev->mdev = mdev;
+ /* cpu_to_mlx5vdpa16() below depends on this flag */
+ mvdev->actual_features =
+ (device_features & BIT_ULL(VIRTIO_F_VERSION_1));
ndev->vqs = kcalloc(max_vqs, sizeof(*ndev->vqs), GFP_KERNEL);
ndev->event_cbs = kcalloc(max_vqs + 1, sizeof(*ndev->event_cbs),
GFP_KERNEL);
--
2.34.1
