15/01/2020 19:35, Ferruh Yigit: > On 1/15/2020 6:49 AM, 方统浩50450 wrote: > > Hi Ferruh, thanks for your message. > > > > > > We developed a ethtool-dpdk which is secondary process based dpdk 17.08 > > version. Our device > > support hotplug detach, but hotplug deatch is failed when we use > > ethtool-dpdk.We found the > > secondary process will change the shared memory when initializing.Secondary > > process calls > > "rte_eth_dev_pci_allocate" function and enters "rte_eth_copy_pci_info" > > function. > > (rte_eth_dev_pci_generic_probe -> rte_eth_dev_pci_allocate -> > > rte_eth_copy_pci_info) > > Then it sets the value of struct "rte_eth_dev_data.dev_flags" to zero.In > > our platform, this value > > is equal to 0x0003.(RTE_ETH_DEV_DETACHABLE | RTE_ETH_DEV_INTR_LSC),but > > after reset > > the "dev_flags", the value changed to 0x0002.(RTE_ETH_DEV_DETACHABLE).So, > > our device hotplug > > detach is failed.I found the similar problem in other dpdk version, include > > dpdk 19.11.Even though > > the deivce hotplug detach is discarded,but i think the shared memory > > changed is unexpected by primary > > process. > > I agree this is the problem. > In the driver code, 'rte_eth_copy_pci_info' is called only by primary process, > but the generic code is faulty. > > And in 19.11 additionally 'eth_dev_pci_specific_init' also seems has same > problem. > > > Our driver is ixgbe, i think this problem has a little relationship with > > driver, Secondary process > > enters "rte_eth_copy_pci_info" by "rte_eth_dev_pci_allocate".And I agree > > your opinion, the helper > > function should simple on what it does.I have two ways to fix this problem, > > one is add an if-statement > > > > in "rte_eth_dev_pci_allocate" function to forbid secondary process enters > > "rte_eth_copy_pci_info" function, > > another way is add an if-statement in "rte_eth_copy_pci_info" function to > > forbid secondary process change > > shared memory.And First way need to ensure the "rte_eth_copy_pci_info" > > function won't be called anywhere else. > > I think the second way is simple and lower risk. > > Yes these are the two options. > > I agree adding check in the 'rte_eth_copy_pci_info' covers all cases and > safer. > BUT my concern was adding decision making to simple/leaf function and make it > harder to debug/use, instead of giving what primary/secondary process should > call decision in higher level. > > But I just recognized that some PMDs are calling 'rte_eth_copy_pci_info' on > secondary process, like mlx4 or szedata2, and most probably this is not their > intention. > And 'eth_dev->intr_handle' set in 'rte_eth_copy_pci_info', not calling this > function may have side affect of 'eth_dev->intr_handle' not set in secondary. > > With above considerations I am OK to your proposal to cover all cases, Thomas, > Andrew, any concern?
Do you mean drivers need to be fixed?
