HI Thomas,
> -----Original Message----- > From: Thomas Monjalon [mailto:tho...@monjalon.net] > Sent: Saturday, July 1, 2017 10:10 PM > To: Tan, Jianfeng > Cc: dev@dpdk.org; yuanhan....@linux.intel.com; > maxime.coque...@redhat.com > Subject: Re: [dpdk-dev] [PATCH] eal: fix secondary process segfault on > multipe virtio devices > > 02/06/2017 18:20, Jianfeng Tan: > > Suppose we have 2 virtio devices for a VM, with only the first one, > > virtio0, binding to igb_uio. Start a primary DPDK process, driving > > only virtio0. Then start a secondary DPDK process, it encounters > > segfault at eth_virtio_dev_init() because hw is NULL, when trying > > to initialize the 2nd virtio devices. > > 1539 if (!hw->virtio_user_dev) { > > > > We could add a precheck to return error when hw is NULL. But the > > root cause is that virtio devices which are not driven by the primary > > process are not exluded by secondary eal probe function. > > > > To support legacy virtio devices bound to none kernel driver, we > > removed RTE_PCI_DRV_NEED_MAPPING in > > commit 962cf902e6eb ("pci: export device mapping functions"). > > At the boot of primary process, ether dev is allocated in rte_eth_devices > > array, rte_eth_dev_data is also allocated in rte_eth_dev_data array; then > > probe function fails; and ether dev is released. However, the entry in > > rte_eth_dev_data array is not cleared. Then we start secondary process, > > and try to attach the virtio device that not used in primary process, > > the field, dev_private (or hw), in rte_eth_dev_data, is NULL. > > > > To fail the dev attach, we need to clear the field, name, when we > > release any ether devices in primary, so that below loop in > > rte_eth_dev_attach_secondary() will not find any matched names. > > for (i = 0; i < RTE_MAX_ETHPORTS; i++) { > > if (strcmp(rte_eth_dev_data[i].name, name) == 0) > > break; > > } > > > > Fixes: 6d890f8ab512 ("Fixes: net/virtio: fix multiple process support") > > It probably needs to be Cc: sta...@dpdk.org > > > Reported-by: Reshma Pattan <reshma.pat...@intel.com> > > Signed-off-by: Jianfeng Tan <jianfeng....@intel.com> > > --- > [...] > > eth_dev->data->dev_private = NULL; > > > > + /* Secondary process will use this field, name, for secondary attach, > > + * clear this field to avoid attaching any released ports in primary. > > + */ > > + memset(eth_dev->data->name, 0, RTE_ETH_NAME_MAX_LEN); > > I think it may be sufficient to set an empty string: > eth_dev->data->name = '\0'; Thank you for the advice. And a new version has been sent. Thanks, Jianfeng
