On 02/04, Konstantin Shkolnyy wrote: > 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@xxxxxxxxxxxxx> > --- > 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 > The patch looks good now. Thanks! Reviewed-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
