From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerin Jacob Subject: Re: [PATCH v3 1/2] eal/pci: introduce a PCI driver flag Date: Tue, 13 Jun 2017 12:54:06 +0530 Message-ID: <20170613072405.GA29658@jerin> References: <20170608114414.8787-1-jerin.jacob@caviumnetworks.com> <11032075.7h2FW7WDNx@xps> <20170613044333.GA5794@jerin> <1987640.XeQgTMmFpU@xps> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@dpdk.org, ferruh.yigit@intel.com To: Thomas Monjalon Return-path: Received: from NAM03-BY2-obe.outbound.protection.outlook.com (mail-by2nam03on0048.outbound.protection.outlook.com [104.47.42.48]) by dpdk.org (Postfix) with ESMTP id 054CE5583 for ; Tue, 13 Jun 2017 09:24:25 +0200 (CEST) Content-Disposition: inline In-Reply-To: <1987640.XeQgTMmFpU@xps> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" -----Original Message----- > Date: Tue, 13 Jun 2017 09:03:56 +0200 > From: Thomas Monjalon > To: Jerin Jacob > Cc: dev@dpdk.org, ferruh.yigit@intel.com > Subject: Re: [dpdk-dev] [PATCH v3 1/2] eal/pci: introduce a PCI driver flag > > 13/06/2017 06:43, Jerin Jacob: > > -----Original Message----- > > > Date: Mon, 12 Jun 2017 18:21:33 +0200 > > > From: Thomas Monjalon > > > To: Jerin Jacob > > > Cc: dev@dpdk.org, ferruh.yigit@intel.com > > > Subject: Re: [dpdk-dev] [PATCH v3 1/2] eal/pci: introduce a PCI driver flag > > > > > > 09/06/2017 12:27, Jerin Jacob: > > > > Some ethdev devices like nicvf thunderx PMD need special treatment for > > > > Secondary queue set(SQS) PCIe VF devices, where, it expects to not unmap > > > > or free the memory without registering the ethdev subsystem. > > > > > > > > Introducing a new RTE_PCI_DRV_KEEP_MAPPED_RES > > > > PCI driver flag to request PCI subsystem to not unmap the mapped PCI > > > > resources(PCI BAR address) if unsupported device detected. > > > > > > > > Suggested-by: Ferruh Yigit > > > > Signed-off-by: Jerin Jacob > > > [...] > > > > --- a/lib/librte_eal/common/eal_common_pci.c > > > > +++ b/lib/librte_eal/common/eal_common_pci.c > > > > @@ -221,7 +221,12 @@ rte_pci_probe_one_driver(struct rte_pci_driver *dr, > > > > ret = dr->probe(dr, dev); > > > > if (ret) { > > > > dev->driver = NULL; > > > > - if (dr->drv_flags & RTE_PCI_DRV_NEED_MAPPING) > > > > + if ((dr->drv_flags & RTE_PCI_DRV_NEED_MAPPING) && > > > > + /* Don't unmap if device is unsupported and > > > > + * driver needs mapped resources. > > > > + */ > > > > + !(ret > 0 && > > > > + (dr->drv_flags & RTE_PCI_DRV_KEEP_MAPPED_RES))) > > > > rte_pci_unmap_device(dev); > > > > } > > > > > > > > --- a/lib/librte_eal/common/include/rte_pci.h > > > > +++ b/lib/librte_eal/common/include/rte_pci.h > > > > +/** Device driver needs to keep mapped resources if unsupported dev detected */ > > > > +#define RTE_PCI_DRV_KEEP_MAPPED_RES 0x0020 > > > > > > If I understand well, you want to map resources but not probe it? > > > > Yes. > > > > > Shouldn't it be less hacky to probe it as a (new) null class? > > > > The Vendor and Class ID is same for those device too so we need to map > > the PCI bar and have access to know the class of device. If you are concerned about > > if it an common code change, My first version was without common code change. > > http://dpdk.org/dev/patchwork/patch/24983/ > > > > Ferruh would like to have flag scheme, I think it make sense for > > PMD maintenance perspective. > > Yes > > My idea was to have a new class of device interface to reserve those > resources, so the probe function would succeed. > Do you think it would be a good idea? Currently Kernel PF code creates 12 SRIOV VF devices per port(one VF device has 8 queues === 96 queues(12VFs) for 96 cores(thunderx max cores)), out of that 1 VF device is _primary_ which mapped to dpdk ethdev port. If probe succeeds for another 11 VFs then too may ethdev NULL ports show up. We can support up to 12 ports(12*12 VF = 144 ports). I think, it is not good from end user perceptive. We already have unsupported device concept in eal device framework(when probe returns > 0). IMHO, it OK to keep as it for simplicity.