Re: [PATCH net-next v2 13/14] sfc: update vdpa device MAC address

[Jason Wang]

在 2023/3/13 14:37, Gautam Dawar 写道:
> On 3/10/23 10:35, Jason Wang wrote:
> > Caution: This message originated from an External Source. Use proper 
> > caution when opening attachments, clicking links, or responding.
> >
> >
> > On Tue, Mar 7, 2023 at 7:38 PM Gautam Dawar <gautam.dawar@xxxxxxx> 
> > wrote:
> > > As the VF MAC address can now be updated using `devlink port 
> > > function set`
> > What happens if we run this while the vpda is being used by a VM?
> IIUC, updating the MAC address using devlink interface requires 
> unbinding the device from driver and hence updating the MAC while vdpa 
> device is in-use won't be possible. It can only be done via control vq 
> VIRTIO_NET_CTRL_MAC_ADDR_SET command, when available.


Good to know that.


> > > interface, fetch the vdpa device MAC address from the underlying VF 
> > > during
> > > vdpa device creation.
> > >
> > > Signed-off-by: Gautam Dawar <gautam.dawar@xxxxxxx>
> > > ---
> > >   drivers/net/ethernet/sfc/ef100_vdpa.c | 12 ++++++++++++
> > >   1 file changed, 12 insertions(+)
> > >
> > > diff --git a/drivers/net/ethernet/sfc/ef100_vdpa.c 
> > > b/drivers/net/ethernet/sfc/ef100_vdpa.c
> > > index 30ca4ab00175..32182a01f6a5 100644
> > > --- a/drivers/net/ethernet/sfc/ef100_vdpa.c
> > > +++ b/drivers/net/ethernet/sfc/ef100_vdpa.c
> > > @@ -272,6 +272,18 @@ static int get_net_config(struct ef100_vdpa_nic 
> > > *vdpa_nic)
> > >          vdpa_nic->net_config.max_virtqueue_pairs =
> > >                  cpu_to_efx_vdpa16(vdpa_nic, 
> > > vdpa_nic->max_queue_pairs);
> > >
> > > +       rc = ef100_get_mac_address(efx, vdpa_nic->mac_address,
> > > +                                  efx->client_id, true);
> > > +       if (rc) {
> > > +               dev_err(&vdpa_nic->vdpa_dev.dev,
> > > +                       "%s: Get MAC for vf:%u failed:%d\n", __func__,
> > > +                       vdpa_nic->vf_index, rc);
> > > +               return rc;
> > > +       }
> > Can this override what is provisioned by the userspace?
>
> No, this was carefully avoided by overwriting the userspace 
> provisioned MAC in ef100_vdpa_create():
>
>         rc = get_net_config(vdpa_nic);
>         if (rc)
>                 goto err_put_device;
>
>         if (mac) {
>                 ether_addr_copy(vdpa_nic->mac_address, mac);
>                 vdpa_nic->mac_configured = true;
>         }


Ah, I see.

Thanks


> > Thanks
> >
> >
> > > +
> > > +       if (is_valid_ether_addr(vdpa_nic->mac_address))
> > > +               vdpa_nic->mac_configured = true;
> > > +
> > >          rc = efx_vdpa_get_mtu(efx, &mtu);
> > >          if (rc) {
> > >                  dev_err(&vdpa_nic->vdpa_dev.dev,
> > > --
> > > 2.30.1