Hello Salva, On Mon, 15 Mar 2021 15:53:51 +0000 Slava Ovsiienko <viachesl...@nvidia.com> wrote:
> Hi, Jan > > Yes, bullet [4] explicitly requires to unbind VFs, and detach the netdevs > from the mlx5_core driver. > Otherwise, kernel driver refuses to be configured with switchdev mode in [5]. > So, [4] can't be skipped. > After setting swithdev mode, VFs can be bound back (if it is needed, and > these ones are not mapped to VMs): OK, but I believe that it is **not possible** to follow the rule [5]. The guide explicitly says in [4] "can be rebind **after** the switchdev mode". Just, if you unbind the device, there is no way how to configure the switchdev mode, this is the contradiction I mentioned in the commit. You cannot configure switchdev mode because the interface is gone and the path /sys/class/net/<net device>/compat/devlink/mode no longer exists. So, maybe, just the formulation is wrong. So, what is the **exact right** way how to do it? I would change the commit accordingly. Just, let's make it right. Would it work this way? # echo -n "<device pci address>" > /sys/bus/pci/drivers/mlx5_core/unbind # echo -n "<device pci address>" > /sys/bus/pci/drivers/mlx5_core/bind # echo switchdev > /sys/class/net/<net device>/compat/devlink/mode It is good to mention that after the rebind, the <net device> can change. Regards, Jan > > echo -n "<device pci address>" > > /sys/bus/pci/drivers/mlx5_core/bind > > With best regards, > Slava > > > -----Original Message----- > > From: Jan Viktorin <ivikto...@fit.vutbr.cz> > > Sent: Monday, March 15, 2021 17:34 > > To: dev@dpdk.org > > Cc: Jan Viktorin <vikto...@cesnet.cz>; Asaf Penso <as...@nvidia.com>; > > Shahaf Shuler <shah...@nvidia.com>; Slava Ovsiienko > > <viachesl...@nvidia.com>; Matan Azrad <ma...@nvidia.com> > > Subject: [PATCH 2/2] net/mlx5: avoid unbind step to enable switchdev mode > > > > From: Jan Viktorin <vikto...@cesnet.cz> > > > > The step 4 is a contradiction. It advices to unbind the device from the > > mlx5_core which removes the associated system network interface (e.g. > > eth0). In the step 5, the same system network interface (e.g. eth0) is > > required to exist. > > > > Signed-off-by: Jan Viktorin <vikto...@cesnet.cz> > > --- > > doc/guides/nics/mlx5.rst | 6 +----- > > 1 file changed, 1 insertion(+), 5 deletions(-) > > > > diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst index > > 0a2dc3dee..122d8e0fc 100644 > > --- a/doc/guides/nics/mlx5.rst > > +++ b/doc/guides/nics/mlx5.rst > > @@ -1370,11 +1370,7 @@ the DPDK application. > > > > echo <num of vfs > /sys/class/net/<net device>/device/sriov_numvfs > > > > -4. Unbind the device (can be rebind after the switchdev mode):: > > - > > - echo -n "<device pci address>" > > > /sys/bus/pci/drivers/mlx5_core/unbind > > - > > -5. Enable switchdev mode:: > > +4. Enable switchdev mode:: > > > > echo switchdev > /sys/class/net/<net device>/compat/devlink/mode > > > > -- > > 2.30.1 >
