Re: [PATCH] vdpa: Set speed and duplex of mlx5_vnet to UNKNOWN

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

On Thu, Aug 29, 2024 at 12:49:24PM +0800, Jason Wang wrote:
> On Thu, Aug 29, 2024 at 2:16 AM Carlos Bilbao
> <carlos.bilbao.osdev@gmail.com> wrote:
> >
> > From: Carlos Bilbao <cbilbao@digitalocean.com>
> >
> > mlx5_vdpa vDPA devices currently don't support reporting or setting the
> > speed and duplex and hence should be UNKNOWN instead of zero.
> >
> > Signed-off-by: Carlos Bilbao <cbilbao@digitalocean.com>
> > ---
> >  drivers/vdpa/mlx5/net/mlx5_vnet.c |  7 +++++++
> >  drivers/vdpa/vdpa.c               | 23 +++++++++++++++++++++++
> >  include/uapi/linux/vdpa.h         |  2 ++
> >  3 files changed, 32 insertions(+)
> >
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index fa78e8288ebb..319f5c6121de 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -3795,6 +3795,13 @@ static int mlx5_vdpa_dev_add(struct vdpa_mgmt_dev *v_mdev, const char *name,
> >         init_rwsem(&ndev->reslock);
> >         config = &ndev->config;
> >
> > +       /*
> > +        * mlx5_vdpa vDPA devices currently don't support reporting or
> > +        * setting the speed or duplex.
> > +        */
> > +       config->speed  = SPEED_UNKNOWN;
> > +       config->duplex = DUPLEX_UNKNOWN;
> > +
> >         if (add_config->mask & BIT_ULL(VDPA_ATTR_DEV_NET_CFG_MTU)) {
> >                 err = config_func_mtu(mdev, add_config->net.mtu);
> >                 if (err)
> > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c
> > index 4dbd2e55a288..abde23e0041d 100644
> > --- a/drivers/vdpa/vdpa.c
> > +++ b/drivers/vdpa/vdpa.c
> > @@ -15,6 +15,7 @@
> >  #include <net/genetlink.h>
> >  #include <linux/mod_devicetable.h>
> >  #include <linux/virtio_ids.h>
> > +#include <uapi/linux/ethtool.h>
> >
> >  static LIST_HEAD(mdev_head);
> >  /* A global mutex that protects vdpa management device and device level operations. */
> > @@ -919,6 +920,22 @@ static int vdpa_dev_net_status_config_fill(struct sk_buff *msg, u64 features,
> >         return nla_put_u16(msg, VDPA_ATTR_DEV_NET_STATUS, val_u16);
> >  }
> >
> > +static int vdpa_dev_net_speed_config_fill(struct sk_buff *msg, u64 features,
> > +                                       struct virtio_net_config *config)
> > +{
> > +       __le32 speed = cpu_to_le32(SPEED_UNKNOWN);
> > +
> > +       return nla_put(msg, VDPA_ATTR_DEV_NET_CFG_SPEED, sizeof(speed), &speed);
> > +}
> > +
> > +static int vdpa_dev_net_duplex_config_fill(struct sk_buff *msg, u64 features,
> > +                                       struct virtio_net_config *config)
> > +{
> > +       u8 duplex = DUPLEX_UNKNOWN;
> > +
> > +       return nla_put(msg, VDPA_ATTR_DEV_NET_CFG_DUPLEX, sizeof(duplex), &duplex);
> > +}
> > +
> >  static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *msg)
> >  {
> >         struct virtio_net_config config = {};
> > @@ -941,6 +958,12 @@ static int vdpa_dev_net_config_fill(struct vdpa_device *vdev, struct sk_buff *ms
> >         if (vdpa_dev_net_status_config_fill(msg, features_device, &config))
> >                 return -EMSGSIZE;
> >
> > +       if (vdpa_dev_net_speed_config_fill(msg, features_device, &config))
> > +               return -EMSGSIZE;
> > +
> > +       if (vdpa_dev_net_duplex_config_fill(msg, features_device, &config))
> > +               return -EMSGSIZE;
> > +
> >         return vdpa_dev_net_mq_config_fill(msg, features_device, &config);
> >  }
> >
> > diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h
> > index 842bf1201ac4..1c64ee0dd7b1 100644
> > --- a/include/uapi/linux/vdpa.h
> > +++ b/include/uapi/linux/vdpa.h
> > @@ -43,6 +43,8 @@ enum vdpa_attr {
> >         VDPA_ATTR_DEV_NET_STATUS,               /* u8 */
> >         VDPA_ATTR_DEV_NET_CFG_MAX_VQP,          /* u16 */
> >         VDPA_ATTR_DEV_NET_CFG_MTU,              /* u16 */
> > +       VDPA_ATTR_DEV_NET_CFG_SPEED,            /* u32 */
> > +       VDPA_ATTR_DEV_NET_CFG_DUPLEX,           /* u8 */
> 
> This should be an independent patch as it allows vdpa tool to
> provision speed and duplex.

or same patch, but document this more clearly:
when subj starts with mlx5 I expect it only affects mlx5.



> But a fundamental question is if we need such provisioning?

why not?

> Thanks
> 
> >
> >         VDPA_ATTR_DEV_NEGOTIATED_FEATURES,      /* u64 */
> >         VDPA_ATTR_DEV_MGMTDEV_MAX_VQS,          /* u32 */
> > --
> > 2.34.1
> >