From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Richardson, Bruce" Subject: Re: [RFC PATCH v2 3/5] librte_ether: add API's for VF management Date: Fri, 23 Sep 2016 09:53:49 +0000 Message-ID: <59AF69C657FD0841A61C55336867B5B035AFEF9E@IRSMSX103.ger.corp.intel.com> References: <1471528125-26357-1-git-send-email-bernard.iremonger@intel.com> <3664576.rt1sgYQyhm@xps13> <20160923092048.GA58328@bricha3-MOBL3> <3936536.tPp6g5Daih@xps13> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: "Iremonger, Bernard" , "dev@dpdk.org" , Jerin Jacob , "Shah, Rahul R" , "Lu, Wenzhuo" , azelezniak To: Thomas Monjalon Return-path: Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by dpdk.org (Postfix) with ESMTP id 95880569F for ; Fri, 23 Sep 2016 11:53:53 +0200 (CEST) In-Reply-To: <3936536.tPp6g5Daih@xps13> Content-Language: en-US List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" > -----Original Message----- > From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com] > Sent: Friday, September 23, 2016 10:36 AM > To: Richardson, Bruce > Cc: Iremonger, Bernard ; dev@dpdk.org; Jerin > Jacob ; Shah, Rahul R > ; Lu, Wenzhuo ; azelezniak > > Subject: Re: [dpdk-dev] [RFC PATCH v2 3/5] librte_ether: add API's for VF > management >=20 > 2016-09-23 10:20, Bruce Richardson: > > On Thu, Sep 22, 2016 at 07:04:37PM +0200, Thomas Monjalon wrote: > > > 2016-09-15 16:46, Iremonger, Bernard: > > > > > > > Do we really need to expose VF specific functions here? > > > > > > > It can be generic(PF/VF) function indexed only through > port_id. > > > > > > > (example: as rte_eth_dev_set_vlan_anti_spoof(uint8_t > > > > > > > port_id, uint8_t on)) For instance, In Thunderx PMD, We are > > > > > > > not exposing a separate port_id for PF. We only enumerate > > > > > > > 0..N VFs as 0..N ethdev port_id > > > > > > > > > > > > Our intention with this patch is to control the VF from the PF. > > > > > > > > > > > > The following librte_ether functions already work in a similar > way: > > > > > > > > > > > > rte_eth_dev_set_vf_rxmode(uint8_t port_id, uint16_t vf, > > > > > > uint16_t rx_mode, uint8_t on) > > > > > > > > > > > > rte_eth_dev_set_vf_rx(uint8_t port_id, uint16_t vf, uint8_t > > > > > > on) > > > > > > > > > > > > rte_eth_dev_set_vf_tx(uint8_t port_id, uint16_t vf, uint8_t > > > > > > on) > > > > > > > > > > > > int rte_eth_set_vf_rate_limit(uint8_t port_id, uint16_t vf, > > > > > > uint16_t tx_rate, uint64_t q_msk) > > > > > > > > > > I have a bad feeling with these functions dedicated to VF from PF= . > > > > > Are we sure there is no other way? > > > > > I mean we just need to know the VF with a port ID. > > > > > > > > When the VF is used in a VM the port ID of the VF is not visible to > the PF. > > > > I don't think there is another way to do this. > > > > > > I don't understand why we could not assign a port id to the VF from > > > the host instead of having the couple PF port id / VF id. > > > Can we enumerate all the VFs associated to a PF? > > > Then can we allocate them a port id in the array rte_eth_devices? > > > > Hi Thomas, > > > > The VF is not a port visible to DPDK, though, so it shouldn't have a > > port id IMHO. DPDK can't actually do anything with it. >=20 > You say the contrary below. Well, yes and no. The driver can manipulate things for the VF, but DPDK doe= sn't actually have a device that corresponds to the VF. There are no PCI ba= r mappings for it, DPDK can't do RX and TX with it etc.? >=20 > > The PCI device for the VF is likely passed through to a different VM > > and being used there. Unfortunately, the VF still needs certain things > > done for it by the PF, so if the PF is under DPDK control, it needs to > > provide the functionality to assist the VF. >=20 > Why not have a VF_from_PF driver which does the mailbox things? > So you can manage the VF from the PF with a simple port id. > It really seems to be the cleanest design to me. While I see your point, and it could work, I just want to be sure that we a= re ok with the results of that. Suppose we do create ethdevs for the VFs co= ntrolled by the PF. Does the new VF get counted in the rte_eth_dev_count() = value (I assume yes)? How are apps meant to use the port? Do they have to p= ut in a special case when iterating through all the port ids to check that = it's not a pseudo port that can't do anything. None of the standard ethdev = calls from an app will work on it, you can't configure nb rx/tx queues on i= t, you can't start or stop it, you can't do rx or tx on it, etc, etc. /Bruce