6.12-stable review patch. If anyone has any objections, please let me know.
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From: Konstantin Shkolnyy kshk@linux.ibm.com
[ Upstream commit 439252e167ac45a5d46f573aac1da7d8f3e051ad ]
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 kshk@linux.ibm.com Message-Id: 20250204173127.166673-1-kshk@linux.ibm.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Reviewed-by: Dragos Tatulea dtatulea@nvidia.com Acked-by: Jason Wang jasowang@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5f581e71e2010..76aedac37a788 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);