> -----Original Message----- > From: Polehn, Mike A > Sent: Thursday, November 5, 2015 3:43 PM > To: Richardson, Bruce <bruce.richardson at intel.com>; Shaham Fridenberg > <ShahamF at Radware.com> > Cc: dev at dpdk.org > Subject: RE: [dpdk-dev] SR-IOV: API to tell VF from PF > > I can think of a very good reason to want to know if the device is VF or > PF. > > The VF has to go through a layer 2 switch, not allowing it to just receive > anything coming across the Ehternet. > > The PF can receive all the packets, including packets with different NIC > addresses. This allow the packets to be just data and allows the > processing of data without needing to be adjusting each NIC L2 address > before sending through to the Ehternet. So data can be moved through a > series of NICs between systems without the extra processing. Not doing > unnecessary processing leaves more clock cycles to do high value > processing. > > Mike >
Yes, the capabilities of the different types of devices are different. However, is a better solution not to provide the ability to query a NIC if it supports promiscuous mode, rather than set up a specific query for a VF? What if (hypothetically) you get a PF that doesn't support promiscuous mode, for instance, or a bifurcated driver where the kernel part prevents the userspace part from enabling promiscuous mode? In both these cases have a direct feature query works better than asking about PF/VF. Regards, /Bruce > -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Bruce Richardson > Sent: Thursday, November 5, 2015 1:51 AM > To: Shaham Fridenberg > Cc: dev at dpdk.org > Subject: Re: [dpdk-dev] SR-IOV: API to tell VF from PF > > On Thu, Nov 05, 2015 at 09:39:19AM +0000, Shaham Fridenberg wrote: > > Hey all, > > > > Is there some API to tell VF from PF? > > > > Only way I found so far is deducing that from driver name in the > rte_eth_devices struct. > > > > Thanks, > > Shaham > > Hi Shaham, > > yes, checking the driver name is probably the only way to do so. However, > why do you need or want to know this? If you want to know the capabilities > of a device basing it on a list of known device types is probably not the > best way. > > Regards, > /Bruce
