> Subject: Re: [Patch v4 03/12] net: mana: Handle vport sharing between > devices > > On Thu, Jul 21, 2022 at 12:06:12AM +0000, Long Li wrote: > > > Subject: Re: [Patch v4 03/12] net: mana: Handle vport sharing > > > between devices > > > > > > On Tue, Jul 12, 2022 at 06:48:09PM +0000, Long Li wrote: > > > > > > @@ -563,9 +581,19 @@ static int mana_cfg_vport(struct > > > > > > mana_port_context *apc, u32 protection_dom_id, > > > > > > > > > > > > apc->tx_shortform_allowed = resp.short_form_allowed; > > > > > > apc->tx_vp_offset = resp.tx_vport_offset; > > > > > > + > > > > > > + netdev_info(apc->ndev, "Configured vPort %llu PD %u > DB %u\n", > > > > > > + apc->port_handle, protection_dom_id, > doorbell_pg_id); > > > > > Should this be netdev_dbg()? > > > > > The log buffer can be flooded if there are many vPorts per VF > > > > > PCI device and there are a lot of VFs. > > > > > > > > The reason netdev_info () is used is that this message is > > > > important for troubleshooting initial setup issues with Ethernet > > > > driver. We rely on user to get this configured right to share the > > > > same hardware port between Ethernet and RDMA driver. As far as I > > > > know, there is no easy way for a driver to "take over" an > > > > exclusive hardware resource from another driver. > > > > > > This seems like a really strange statement. > > > > > > Exactly how does all of this work? > > > > > > Jason > > > > "vport" is a hardware resource that can either be used by an Ethernet > > device, or an RDMA device. But it can't be used by both at the same > > time. The "vport" is associated with a protection domain and doorbell, > > it's programmed in the hardware. Outgoing traffic is enforced on this > > vport based on how it is programmed. > > Sure, but how is the users problem to "get this configured right" and what > exactly is the user supposed to do? > > I would expect the allocation of HW resources to be completely transparent > to the user. Why is it not? > > Jason In the hardware, RDMA RAW_QP shares the same hardware resource (in this case, the vPort in hardware table) with the ethernet NIC. When an RDMA user creates a RAW_QP, we can't just shut down the ethernet. The user is required to make sure the ethernet is not in used when he creates this QP type.
