On Wed, Feb 5, 2025 at 2:16 AM Dragos Tatulea <dtatulea@xxxxxxxxxx> wrote: > > 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> > Acked-by: Jason Wang <jasowang@xxxxxxxxxx> Thanks
