Hi Tetsuya, On Sat, Feb 21, 2015 at 4:49 AM, Tetsuya Mukawa <mukawa at igel.co.jp> wrote: > On 2015/02/21 0:20, Maxime Leroy wrote: [...] >> Why you want to add devargs in the devargs_list, if there are no needs >> to store this information ? > > In eal initialization code, virtual device names stored in devargs are > checked not to register a same device name twice. > And each init function of PMD just trust a device name received by eal. > So there is no code in PMD to check whether device name is unique. >
I disagree with you. This check is not present in the master branch. You have added this check in your hotplug patchset, in this patch: [PATCH v10 10/14] eal/pci: Add a function to remove the entry of devargs list See: http://dpdk.org/ml/archives/dev/2015-February/013712.html Thus the problem should be already exist without your patches in the master branch. For example according to you, this testpmd command should create 2 devices with the same name: testpmd -c 0xc --vdev eth_pcap0,iface=eth0 --vdev eth_pcap0,iface=eth1 -n 2 -- -i But it's not the case: PMD: Initializing pmd_pcap for eth_pcap0 PMD: Creating pcap-backed ethdev on numa socket 0 PMD: Initializing pmd_pcap for eth_pcap0 PMD: Creating pcap-backed ethdev on numa socket 0 PMD: rte_eth_dev_allocate: Ethernet Device with name eth_pcap0 already allocated! In fact, it's not possible for any PMD_VDEV in the dpdk repo to create 2 devices with the same name. All the virtual device initialization functions use the rte_eth_dev_allocate function. This function prevents to create two ethernet devices with the same name: if (rte_eth_dev_allocated(name) != NULL) { PMD_DEBUG_TRACE("Ethernet Device with name %s already allocated!\n", name); return NULL; } > For example, according to your suggestion, how to prevent below case? > $ ./testpmd -c f -n 1 -- -i > testpmd> port attach eth_pcap0,iface=eth0 > testpmd> port attach eth_pcap0,iface=eth1 > > Also, type below, after doing above. > testpmd> port detach 0 > > Probably port 0 will be "eth_pcap0,iface=eth0". > But uninit code of PMD only receives a device name like 'eth_pcap0'. > (We have 2 'eth_pcap0' devices in PMD.) > > To prevent above case, probably we have 2 options at least. > One is changing init code of all virtual PMDs not to register same > device name. There are no need to change init code of all virtual PMDs to not register the same device name 2 times. Because it's already not possible to create 2 virtual device with the same name. (see my point above) > The other is to use devargs_list in EAL, and call init code of PMD with > a unique device name. Thus there are no needs to use the devargs_list for that. > [..] >> >> But you don't call rte_eal_devargs_add with RTE_DEVTYPE_WHILISTED_PCI >> in rte_eal_dev_attach_pdev ? > > Yes, I don't. > Hotplug functions should not change BLACKLIST and WHITELIST. > So not to touch the list is correct behavior. Yes the correct behaviour for Hotplug functions is to not use the devargs_list for physical and virtual devices ! Regards, Maxime
