Re: [PATCH v2] vdpa/mlx5: should not activate virtq object when suspended

[Si-Wei Liu]

On 2/13/2023 10:20 PM, Jason Wang wrote:
> On Tue, Feb 14, 2023 at 6:48 AM Si-Wei Liu <si-wei.liu@xxxxxxxxxx> wrote:
> > Otherwise the virtqueue object to instate could point to invalid address
> > that was unmapped from the MTT:
> >
> >    mlx5_core 0000:41:04.2: mlx5_cmd_out_err:782:(pid 8321):
> >    CREATE_GENERAL_OBJECT(0xa00) op_mod(0xd) failed, status
> >    bad parameter(0x3), syndrome (0x5fa1c), err(-22)
> >
> > Fixes: cae15c2ed8e6 ("vdpa/mlx5: Implement susupend virtqueue callback")
> > Cc: Eli Cohen <elic@xxxxxxxxxx>
> > Signed-off-by: Si-Wei Liu <si-wei.liu@xxxxxxxxxx>
> >
> > ---
> > v2: removed the change for improving warning message
> > ---
> >   drivers/vdpa/mlx5/net/mlx5_vnet.c | 7 ++++++-
> >   1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index 3a6dbbc6..d7e8ca0 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -165,6 +165,7 @@ struct mlx5_vdpa_net {
> >          u32 cur_num_vqs;
> >          u32 rqt_size;
> >          bool nb_registered;
> > +       bool suspended;
> Any reason we make this net specific? (or is it better to use
> mlx5_vdpa_dev structure?)
Yep, I can make this change, suspend should not be net specific.

> >          struct notifier_block nb;
> >          struct vdpa_callback config_cb;
> >          struct mlx5_vdpa_wq_ent cvq_ent;
> > @@ -2411,7 +2412,7 @@ static int mlx5_vdpa_change_map(struct mlx5_vdpa_dev *mvdev,
> >          if (err)
> >                  goto err_mr;
> >
> > -       if (!(mvdev->status & VIRTIO_CONFIG_S_DRIVER_OK))
> > +       if (!(mvdev->status & VIRTIO_CONFIG_S_DRIVER_OK) || ndev->suspended)
> >                  goto err_mr;
> >
> >          restore_channels_info(ndev);
> > @@ -2580,6 +2581,7 @@ static int mlx5_vdpa_reset(struct vdpa_device *vdev)
> >          mlx5_vdpa_destroy_mr(&ndev->mvdev);
> >          ndev->mvdev.status = 0;
> >          ndev->cur_num_vqs = 0;
> > +       ndev->suspended = false;
> >          ndev->mvdev.cvq.received_desc = 0;
> >          ndev->mvdev.cvq.completed_desc = 0;
> >          memset(ndev->event_cbs, 0, sizeof(*ndev->event_cbs) * (mvdev->max_vqs + 1));
> > @@ -2815,6 +2817,8 @@ static int mlx5_vdpa_suspend(struct vdpa_device *vdev)
> >          struct mlx5_vdpa_virtqueue *mvq;
> >          int i;
> >
> > +       mlx5_vdpa_info(mvdev, "suspending device\n");
> > +
> Is this better to show the info after the device has been suspended?
I'm not sure, the current convention of this driver (for e.g. 
mlx5_vdpa_reset) is to log info at the function entry to inform some 
action is about to happen, and log a warning if running into any 
failure; otherwise if no subsequent warning but other logs following the 
info notice, it means the action has been successfully done. I thought 
at least there's some value to log at the start of the function just in 
case it's getting stuck in the middle.

Thanks,
-Siwei

> Thanks
>
> >          down_write(&ndev->reslock);
> >          ndev->nb_registered = false;
> >          mlx5_notifier_unregister(mvdev->mdev, &ndev->nb);
> > @@ -2824,6 +2828,7 @@ static int mlx5_vdpa_suspend(struct vdpa_device *vdev)
> >                  suspend_vq(ndev, mvq);
> >          }
> >          mlx5_vdpa_cvq_suspend(mvdev);
> > +       ndev->suspended = true;
> >          up_write(&ndev->reslock);
> >          return 0;
> >   }
> > --
> > 1.8.3.1