Re: [PATCH v3 08/13] vdpa: add return value to get_config/set_config callbacks
From: Stefano Garzarella
Date: Fri Feb 05 2021 - 17:59:07 EST
On Fri, Feb 05, 2021 at 09:11:26AM -0500, Michael S. Tsirkin wrote:
On Fri, Feb 05, 2021 at 09:48:47AM +0100, Stefano Garzarella wrote:
Adding Eli in the loop.
On Fri, Feb 05, 2021 at 11:20:11AM +0800, Jason Wang wrote:
>
> On 2021/2/5 上午1:22, Stefano Garzarella wrote:
> > All implementations of these callbacks already validate inputs.
> >
> > Let's return an error from these callbacks, so the caller doesn't
> > need to validate the input anymore.
> >
> > We update all implementations to return -EINVAL in case of invalid
> > input.
> >
> > Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> > ---
> > include/linux/vdpa.h | 18 ++++++++++--------
> > drivers/vdpa/ifcvf/ifcvf_main.c | 24 ++++++++++++++++--------
> > drivers/vdpa/mlx5/net/mlx5_vnet.c | 17 +++++++++++------
> > drivers/vdpa/vdpa_sim/vdpa_sim.c | 16 ++++++++++------
> > 4 files changed, 47 insertions(+), 28 deletions(-)
> >
> > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h
> > index 4ab5494503a8..0e0cbd5fb41b 100644
> > --- a/include/linux/vdpa.h
> > +++ b/include/linux/vdpa.h
> > @@ -157,6 +157,7 @@ struct vdpa_iova_range {
> > * @buf: buffer used to read to
> > * @len: the length to read from
> > * configuration space
> > + * Returns integer: success (0) or error (< 0)
> > * @set_config: Write to device specific configuration space
> > * @vdev: vdpa device
> > * @offset: offset from the beginning of
> > @@ -164,6 +165,7 @@ struct vdpa_iova_range {
> > * @buf: buffer used to write from
> > * @len: the length to write to
> > * configuration space
> > + * Returns integer: success (0) or error (< 0)
> > * @get_generation: Get device config generation (optional)
> > * @vdev: vdpa device
> > * Returns u32: device generation
> > @@ -231,10 +233,10 @@ struct vdpa_config_ops {
> > u32 (*get_vendor_id)(struct vdpa_device *vdev);
> > u8 (*get_status)(struct vdpa_device *vdev);
> > void (*set_status)(struct vdpa_device *vdev, u8 status);
> > - void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
> > - void *buf, unsigned int len);
> > - void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
> > - const void *buf, unsigned int len);
> > + int (*get_config)(struct vdpa_device *vdev, unsigned int offset,
> > + void *buf, unsigned int len);
> > + int (*set_config)(struct vdpa_device *vdev, unsigned int offset,
> > + const void *buf, unsigned int len);
> > u32 (*get_generation)(struct vdpa_device *vdev);
> > struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);
> > @@ -329,8 +331,8 @@ static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
> > }
> > -static inline void vdpa_get_config(struct vdpa_device *vdev, unsigned offset,
> > - void *buf, unsigned int len)
> > +static inline int vdpa_get_config(struct vdpa_device *vdev, unsigned offset,
> > + void *buf, unsigned int len)
> > {
> > const struct vdpa_config_ops *ops = vdev->config;
> > @@ -339,8 +341,8 @@ static inline void vdpa_get_config(struct vdpa_device *vdev, unsigned offset,
> > * If it does happen we assume a legacy guest.
> > */
> > if (!vdev->features_valid)
> > - vdpa_set_features(vdev, 0);
> > - ops->get_config(vdev, offset, buf, len);
> > + return vdpa_set_features(vdev, 0);
> > + return ops->get_config(vdev, offset, buf, len);
> > }
> > /**
> > diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
> > index 7c8bbfcf6c3e..f5e6a90d8114 100644
> > --- a/drivers/vdpa/ifcvf/ifcvf_main.c
> > +++ b/drivers/vdpa/ifcvf/ifcvf_main.c
> > @@ -332,24 +332,32 @@ static u32 ifcvf_vdpa_get_vq_align(struct vdpa_device *vdpa_dev)
> > return IFCVF_QUEUE_ALIGNMENT;
> > }
> > -static void ifcvf_vdpa_get_config(struct vdpa_device *vdpa_dev,
> > - unsigned int offset,
> > - void *buf, unsigned int len)
> > +static int ifcvf_vdpa_get_config(struct vdpa_device *vdpa_dev,
> > + unsigned int offset,
> > + void *buf, unsigned int len)
> > {
> > struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
> > - WARN_ON(offset + len > sizeof(struct virtio_net_config));
> > + if (offset + len > sizeof(struct virtio_net_config))
> > + return -EINVAL;
> > +
> > ifcvf_read_net_config(vf, offset, buf, len);
> > +
> > + return 0;
> > }
> > -static void ifcvf_vdpa_set_config(struct vdpa_device *vdpa_dev,
> > - unsigned int offset, const void *buf,
> > - unsigned int len)
> > +static int ifcvf_vdpa_set_config(struct vdpa_device *vdpa_dev,
> > + unsigned int offset, const void *buf,
> > + unsigned int len)
> > {
> > struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
> > - WARN_ON(offset + len > sizeof(struct virtio_net_config));
> > + if (offset + len > sizeof(struct virtio_net_config))
> > + return -EINVAL;
> > +
> > ifcvf_write_net_config(vf, offset, buf, len);
> > +
> > + return 0;
> > }
> > static void ifcvf_vdpa_set_config_cb(struct vdpa_device *vdpa_dev,
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index 029822060017..9323b5ff7988 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -1796,20 +1796,25 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
> > ndev->mvdev.status |= VIRTIO_CONFIG_S_FAILED;
> > }
> > -static void mlx5_vdpa_get_config(struct vdpa_device *vdev, unsigned int offset, void *buf,
> > - unsigned int len)
> > +static int mlx5_vdpa_get_config(struct vdpa_device *vdev, unsigned int offset, void *buf,
> > + unsigned int len)
> > {
> > struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
> > struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);
> > - if (offset + len < sizeof(struct virtio_net_config))
> > - memcpy(buf, (u8 *)&ndev->config + offset, len);
> > + if (offset + len > sizeof(struct virtio_net_config))
> > + return -EINVAL;
>
>
> It looks to me we should use ">=" here?
Ehmm, I think it was wrong before this patch. If 'offset + len' is equal to
'sizeof(struct virtio_net_config)', should be okay to copy, no?
I think it's one of the rare cases where the copy and paste went well :-)
Should I fix this in a separate patch?
Thanks,
Stefano
Sure.
I'll do it.
Thanks,
Stefano