Re: [PATCH 02/10] vDPA: report virtio-block max segment size to user space

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Mar 29, 2024 at 10:48:25PM +0800, Zhu, Lingshan wrote:
> 
> 
> On 3/20/2024 12:04 AM, Stefano Garzarella wrote:
> > On Mon, Feb 19, 2024 at 02:55:58AM +0800, Zhu Lingshan wrote:
> > > This commit allows reporting the max size of any
> > > single segment of virtio-block devices to user space.
> > > 
> > > Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
> > > ---
> > > drivers/vdpa/vdpa.c       | 17 +++++++++++++++++
> > > include/uapi/linux/vdpa.h |  1 +
> > > 2 files changed, 18 insertions(+)
> > > 
> > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> > > index d5ccb618de2b..ee1472d32b0d 100644
> > > --- a/drivers/vdpa/vdpa.c
> > > +++ b/drivers/vdpa/vdpa.c
> > > @@ -956,6 +956,20 @@ vdpa_dev_blk_capacity_config_fill(struct
> > > sk_buff *msg,
> > >                  val_u64, VDPA_ATTR_PAD);
> > > }
> > > 
> > > +static int
> > > +vdpa_dev_blk_seg_size_config_fill(struct sk_buff *msg, u64 features,
> > > +                  const struct virtio_blk_config *config)
> > > +{
> > > +    u32 val_u32;
> > > +
> > > +    if ((features & BIT_ULL(VIRTIO_BLK_F_SIZE_MAX)) == 0)
> > > +        return 0;
> > > +
> > > +    val_u32 = __virtio32_to_cpu(true, config->size_max);
> > > +
> > > +    return nla_put_u32(msg, VDPA_ATTR_DEV_BLK_CFG_SEG_SIZE, val_u32);
> > 
> > Should we call this VDPA_ATTR_DEV_BLK_CFG_SIZE_MAX ?
> I have tried this before, but this macro is too long causing a odd format in
> the header file.
> 
> I can change this since you point this out. This is uapi means we should
> merge the
> fix during the RC release before 6.9 official.
> 
> @MST, does the process work for you?


I'm fine applying a fixup patch. Yes it's preferable to make changed
before the release.

> > 
> > > +}
> > > +
> > > static int vdpa_dev_blk_config_fill(struct vdpa_device *vdev,
> > >                     struct sk_buff *msg)
> > > {
> > > @@ -973,6 +987,9 @@ static int vdpa_dev_blk_config_fill(struct
> > > vdpa_device *vdev,
> > >     if (vdpa_dev_blk_capacity_config_fill(msg, &config))
> > >         return -EMSGSIZE;
> > > 
> > > +    if (vdpa_dev_blk_seg_size_config_fill(msg, features_device,
> > > &config))
> > > +        return -EMSGSIZE;
> > > +
> > >     return 0;
> > > }
> > > 
> > > diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
> > > index 1bf69226cb96..586bce3c906a 100644
> > > --- a/include/uapi/linux/vdpa.h
> > > +++ b/include/uapi/linux/vdpa.h
> > > @@ -57,6 +57,7 @@ enum vdpa_attr {
> > >     VDPA_ATTR_DEV_FEATURES,                 /* u64 */
> > > 
> > >     VDPA_ATTR_DEV_BLK_CFG_CAPACITY,        /* u64 */
> > > +    VDPA_ATTR_DEV_BLK_CFG_SEG_SIZE,        /* u32 */
> > > 
> > >     /* new attributes must be added above here */
> > >     VDPA_ATTR_MAX,
> > > -- 
> > > 2.39.3
> > > 
> > > 
> > 
> >