On Tue, Sep 08, 2020 at 10:08:39PM -0400, Jason Wang wrote:
>
>
> ----- Original Message -----
> > set_map() is used by mlx5 vdpa to create a memory region based on the
> > address map passed by the iotlb argument. If we get successive calls, we
> > will destroy the current memory region and build another one based on
> > the new address mapping. We also need to setup the hardware resources
> > since they depend on the memory region.
> >
> > If these calls happen before DRIVER_OK, It means that driver VQs may
> > also not been setup and we may not create them yet. In this case we want
> > to avoid setting up the other resources and defer this till we get
> > DRIVER OK.
> >
> > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5
> > devices")
> > Signed-off-by: Eli Cohen <e...@nvidia.com>
> > ---
> > V1->V2: Improve changelog description
> >
> > 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 9df69d5efe8c..c89cd48a0aab 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -1645,6 +1645,9 @@ static int mlx5_vdpa_change_map(struct mlx5_vdpa_net
> > *ndev, struct vhost_iotlb *
> > if (err)
> > goto err_mr;
> >
> > + if (!(ndev->mvdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
> > + return 0;
> > +
>
> Is there any reason that we still need to do vq suspending and saving before?
>
Though suspend_vqs() and save_channels_info() will be called, they will
not actually do any work because the mvq->initialized is false.
Since we don't expect so many false map updates I think it makes sense
to avoid logic around the calls suspend_vqs() and save_channels_info().
> Thanks
>
> > restore_channels_info(ndev);
> > err = setup_driver(ndev);
> > if (err)
> > --
> > 2.26.0
> >
> >
>
