From: Ferruh Yigit <ferruh.yigit@intel.com> To: 方统浩50450 <fangtonghao@sangfor.com.cn> Cc: Andrew Rybchenko <arybchenko@solarflare.com>, Thomas Monjalon <thomas@monjalon.net>, dev@dpdk.org, stable@dpdk.org, jia.guo@intel.com, cunming.liang@intel.com, qi.z.zhang@intel.com, jungle845943968@outlook.com, Jerin Jacob Kollanukkaran <jerinj@marvell.com> Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH v2] Fixes: ethdev: secondary process change shared memory Date: Thu, 16 Jan 2020 12:18:18 +0000 Message-ID: <61a10224-b316-2dd1-0bc1-9db64643bbff@intel.com> (raw) In-Reply-To: <AM6AEwBQCIJk9JP063jdHKr*.3.1579174548054.Hmail.fangtonghao@sangfor.com.cn> 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.yigit@intel.com> > 发送日期:2020-01-16 17:04:09 > 收件人:Andrew Rybchenko <arybchenko@solarflare.com>,Thomas Monjalon <thomas@monjalon.net> > 抄送人:"方统浩50450" <fangtonghao@sangfor.com.cn>,dev@dpdk.org,stable@dpdk.org,jia.guo@intel.com,cunming.liang@intel.com,qi.z.zhang@intel.com,jungle845943968@outlook.com,Jerin Jacob Kollanukkaran <jerinj@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. > >
next prev parent reply other threads:[~2020-01-16 12:18 UTC|newest] Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-09 12:27 [dpdk-stable] [PATCH] ethdev: fix secondary process change share memory Fang TongHao 2020-01-10 7:30 ` Jeff Guo 2020-01-10 7:53 ` 方统浩50450 2020-01-13 5:03 ` [dpdk-stable] [PATCH v2] Fixes: ethdev: secondary process change shared memory Fang TongHao 2020-01-14 14:45 ` [dpdk-stable] [dpdk-dev] " Ferruh Yigit 2020-01-15 6:49 ` 方统浩50450 2020-01-15 18:35 ` Ferruh Yigit 2020-01-15 20:43 ` Thomas Monjalon 2020-01-16 7:43 ` Andrew Rybchenko 2020-01-16 9:04 ` Ferruh Yigit 2020-01-16 11:35 ` 方统浩50450 2020-01-16 12:18 ` Ferruh Yigit [this message] 2020-01-17 2:11 ` 方统浩50450 2020-01-16 9:00 ` Ferruh Yigit 2020-01-17 2:08 ` [dpdk-stable] [PATCH v3] " Fang TongHao 2020-01-17 8:33 ` Andrew Rybchenko 2020-01-17 17:58 ` [dpdk-stable] [dpdk-dev] " Ferruh Yigit
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