On 1/16/2020 11:35 AM, 方统浩50450 wrote: > > >>@Fang, only can you please make a new version to update the >>'rte_eth_copy_pci_info' function comment to document shared data is not >>updated >>for the secondary process? > >>So this suggest going on with Fang's patch. I only requested an additional >>note >>in function comment related to this secondary check. > > @Ferruh Yigit > Should I update a new version patch of "rte_eth_copy_pci_info" function and > explain > wthether the regular functioning of secondary process is affected or not? > I cant figure out what you need me to do.
Hi Fang, Yes can you please send a new version of your patch. In new version, additionally update the 'rte_eth_copy_pci_info()' function comment to document that function updates 'eth_dev->data' only for primary process. Thanks, ferruh > > > 发件人：Ferruh Yigit <ferruh.yi...@intel.com> > 发送日期：2020-01-16 17:04:09 > 收件人：Andrew Rybchenko <arybche...@solarflare.com>,Thomas Monjalon > <tho...@monjalon.net> > 抄送人："方统浩50450" > <fangtong...@sangfor.com.cn>,dev@dpdk.org,sta...@dpdk.org,jia....@intel.com,cunming.li...@intel.com,qi.z.zh...@intel.com,jungle845943...@outlook.com,Jerin > Jacob Kollanukkaran <jer...@marvell.com> > 主题：Re: [dpdk-dev] [PATCH v2] Fixes: ethdev: secondary process change shared > memory>On 1/16/2020 7:43 AM, Andrew Rybchenko wrote: >>> On 1/15/20 11:43 PM, Thomas Monjalon wrote: >>>> 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. >>> >>> Hold on, just for my understanding. As far as I can see >>> RTE_ETH_DEV_DETACHABLE was removed in 17.11. Does it >>> change something in above description? >> >>Overall secondary overwrites primary values, I think we should fix it >>independent from the flags involved. >> >>> >>>>> 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. >>> >>> Yes, as I understand RTE_ETH_DEV_CLOSE_REMOVE, >>> RTE_ETH_DEV_BONDED_SLAVE, RTE_ETH_DEV_REPRESENTOR and >>> RTE_ETH_DEV_NOLIVE_MAC_ADDR may be lost because of >>> reinit (if not restored in other branches). Bad anyway. >>> >>>>>> 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? >>> >>> I would put if condition in rte_eth_copy_pci_info(). >>> It is the function which writes shared space from >>> secondary process when it should not be done and it >>> should be fixed there. >> >>OK >> >>> >>>> Do you mean drivers need to be fixed? >>> >>> I'm not sure that I fully understand it. Since copy function >>> cares about intr_handle copying I'm afraid that it is not >>> 100% correct to skip it in secondary process completely as >>> many drivers do right now. Basically it makes eth_dev structure >>> in secondary process inconsistent. However, it looks like >>> most of these drivers simply obtain handle from pci_dev >>> directly and it explains why they are not affected. >>> There are exceptions which are potentially bugs, e.g. >>> drivers/net/ice/ice_ethdev.c: ice_interrupt_handler at the end. >>> >>> I think that it would be better if intr_handle is always >>> correct in eth_dev (both primary and secondary cases) and >>> drivers use it instead of the same from pci_dev. >>> >> >>OK >> >>So this suggest going on with Fang's patch. I only requested an additional >>note >>in function comment related to this secondary check. > >
