On 8/12/19 4:57 PM, Andrew Lunn wrote: >> In the DPAA2 architecture MACs are not the only entities that can be >> connected to a switch port. >> Below is an exemple of a 4 port DPAA2 switch which is configured to >> interconnect 2 DPNIs (network interfaces) and 2 DPMACs. >> >> >> [ethA] [ethB] [ethC] [ethD] [ethE] [ethF] >> : : : : : : >> : : : : : : >> [eth drv] [eth drv] [ ethsw drv ] >> : : : : : : kernel >> ======================================================================== >> : : : : : : >> hardware >> [DPNI] [DPNI] [============= DPSW =================] >> | | | | | | >> | ---------- | [DPMAC] [DPMAC] >> ------------------------------- | | >> | | >> [PHY] [PHY] >> >> You can see it as a hardware-accelerated software bridge where >> forwarding rules are managed from the host software partition. > > Hi Ioana
Hi Andrew, > > What are the use cases for this? > > Configuration is rather unintuitive. To bridge etha and ethb you need > to > > ip link add name br0 type bridge > ip link set ethc master br0 > ip link set ethd master br0 > > And once you make ethc and ethd actually send/receive frames, etha and > ethc become equivalent. > > If this was a PCI device, i could imagine passing etha into a VM as a > PCI VF. But i don't think it is PCI? Indeed it's not PCI but we can pass etha to a VM. That's the main use case of having DPNIs connected to a switch object. Our direct assignment solution for DPAA2 is not upstream yet (the case with many of our drivers :) ) but the main idea is exposing to the VM a fsl-mc bus on which it can find any DPAA2 objects needed to configure a network interface (using firmware calls). > > I'm not sure moving etha into a different name space makes much sense > either. My guess would be, a veth pair with one end connected to the > software bridge would be more efficient than DMAing the packet out and > then back in again. > > Thanks > Andrew > That's really an interesting test to be made since we can make a veth pair from DPAA2 objects just connecting two DPNIs back to back. I'll make some performance tests and compare against the software veth. Thanks, Ioana
