On Mon, Nov 30, 2020 at 08:27:46AM +0200, Eli Cohen wrote: > On Sun, Nov 29, 2020 at 03:08:22PM -0500, Michael S. Tsirkin wrote: > > On Sun, Nov 29, 2020 at 08:43:51AM +0200, Eli Cohen wrote: > > > We should not try to use the VF MAC address as that is used by the > > > regular (e.g. mlx5_core) NIC implementation. Instead, use a random > > > generated MAC address. > > > > > > Suggested by: Cindy Lu <[email protected]> > > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 > > > devices") > > > Signed-off-by: Eli Cohen <[email protected]> > > > > I didn't realise it's possible to use VF in two ways > > with and without vdpa. > > Using a VF you can create quite a few resources, e.g. send queues > recieve queues, virtio_net queues etc. So you can possibly create > several instances of vdpa net devices and nic net devices. > > > Could you include a bit more description on the failure > > mode? > > Well, using the MAC address of the nic vport is wrong since that is the > MAC of the regular NIC implementation of mlx5_core.
Right but ATM it doesn't coexist with vdpa so what's the problem? > > Is switching to a random mac for such an unusual > > configuration really justified? > > Since I can't use the NIC's MAC address, I have two options: > 1. To get the MAC address as was chosen by the user administering the > NIC. This should invoke the set_config callback. Unfortunately this > is not implemented yet. > > 2. Use a random MAC address. This is OK since if (1) is implemented it > can always override this random configuration. > > > It looks like changing a MAC could break some guests, > > can it not? > > > > No, it will not. The current version of mlx5 VDPA does not allow regular > NIC driver and VDPA to co-exist. I have patches ready that enable that > from steering point of view. I will post them here once other patches on > which they depend will be merged. > > https://patchwork.ozlabs.org/project/netdev/patch/[email protected]/ Could you be more explicit on the following points: - which configuration is broken ATM (as in, two device have identical macs? any other issues)? - why won't device MAC change from guest point of view? > > > --- > > > drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +---- > > > 1 file changed, 1 insertion(+), 4 deletions(-) > > > > > > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c > > > b/drivers/vdpa/mlx5/net/mlx5_vnet.c > > > index 1fa6fcac8299..80d06d958b8b 100644 > > > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c > > > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c > > > @@ -1955,10 +1955,7 @@ void *mlx5_vdpa_add_dev(struct mlx5_core_dev *mdev) > > > if (err) > > > goto err_mtu; > > > > > > - err = mlx5_query_nic_vport_mac_address(mdev, 0, 0, config->mac); > > > - if (err) > > > - goto err_mtu; > > > - > > > + eth_random_addr(config->mac); > > > mvdev->vdev.dma_dev = mdev->device; > > > err = mlx5_vdpa_alloc_resources(&ndev->mvdev); > > > if (err) > > > -- > > > 2.26.2 > >
