Hi Stanislav, Following are the steps to reproduce in VPP 20.09:
ip link add name vcsr-f1c1 type veth peer name f1c1 ip link set dev f1c1 up ip link set dev vcsr-f1c1 up create host-interface name vcsr-f1c1 lcp create host-vcsr-f1c1 host-if Ethernet0 check in show tap <tap interface > Check for fd in /proc/<pid of vpp>/fd check in "show unix files" Thanks Pragya On Fri, 3 Mar, 2023, 8:34 pm Stanislav Zaikin, <zsta...@gmail.com> wrote: > Hi Pragya, > > Could you provide me with the steps to reproduce? > > On Tue, 28 Feb 2023 at 14:10, Pragya Nand Bhagat < > pragya.nand.bhaga...@gmail.com> wrote: > >> Hi Stanislav, >> >> I debug it further. Here are the steps >> >> 1> In my config I am creating a veth interface in kernel >> 2> for that interface I am creating a hostif interface using "create >> host-interface name <NAME>" >> 3> This intern create 4 fds in "show unix files" >> 4> >> [image: image.png] >> >> 5> I think this 59 fd is fd of af_packet socket for hostif. Correct me >> if I am wrong. >> 6> but I don't see any inode entry for it in /proc/<PID>/fd >> 7> So according to my understanding for other tap creation it tries to >> take 59 as free fd and allocate >> 8> that happens to be in bvi tap interface creation >> 9> and that causes traffic flow issues. >> >> Do you see its a valid analysis? Please provide your comments and let me >> know your thoughts on this. >> >> Thanks, >> Pragya >> >> >> On Tue, Feb 28, 2023 at 4:13 PM Pragya Nand Bhagat via lists.fd.io >> <pragya.nand.bhagat.1=gmail....@lists.fd.io> wrote: >> >>> Hi Stanislav, >>> >>> Thanks for the response. >>> Please find the response inline >>> >>> >>> Do you see any errors in `show log`? >>> >>>>[Pragya] No I don't see any error log >>> >>> Do you see this fd 59 in `show unix files`? >>> >>>>[Pragya] Yes, I can see 59 in show unix files >>> "show unix files" fetch the fd from "/proc/self/fd/" >>> but if we go and see /proc/<pid>/fd we don't see any file inode being >>> created. >>> >>> So according to OS 59 is never assigned and for subsequent interface >>> creation it try to have that same tap fd which is 59 here. >>> I think that causes the issue where the traffic flow is not OK. >>> >>> Can you suggest how I can debug and address this issue? >>> >>> Thanks, >>> Pragya >>> >>> >>> On Fri, Feb 24, 2023 at 3:24 PM Stanislav Zaikin <zsta...@gmail.com> >>> wrote: >>> >>>> Hello Pragya, >>>> >>>> Do you see any errors in `show log`? >>>> Do you see this fd 59 in `show unix files`? >>>> >>>> On Fri, 24 Feb 2023 at 07:59, Pragya Nand Bhagat < >>>> pragya.nand.bhaga...@gmail.com> wrote: >>>> >>>>> Hi All, >>>>> >>>>> I'm using an older version of vpp 20.09 . >>>>> When I create a bvi interface using bvi create cli. >>>>> A corresponding tap is created with same name as follows: >>>>> >>>>> >>>>> >>>>> *itf-pair: [19] bvi100 tap-39-bvi100 bvi100 960 type tap * >>>>> >>>>> But one FD of the tap interface is *missing* when I check in linux. >>>>> >>>>> vpp# *show tap tap-39-bvi100* >>>>> >>>>> Interface: tap-39-bvi100 (ifindex 40) >>>>> >>>>> name "bvi100" >>>>> >>>>> host-ns "(nil)" >>>>> >>>>> host-mac-addr: e4:43:4b:21:f3:86 >>>>> >>>>> *vhost-fds 213 214* >>>>> >>>>> * tap-fds 59* >>>>> >>>>> gso-enabled 0 >>>>> >>>>> csum-enabled 0 >>>>> >>>>> >>>>> In above output there should be 3 FDs associated with the tap but* >>>>> one of them is missing.* >>>>> >>>>> [root@0-9 /]# ls -l /proc/37/fd | grep 59 >>>>> >>>>> lrwx------ 1 root root 64 Feb 23 12:03 159 -> /dev/vhost-net >>>>> >>>>> *FD 59 is missing*, as a result of which packet transfer between >>>>> linux and mdp is not happening. >>>>> >>>>> Is there some checkin/patch to fix this issue? >>>>> Any help in debugging this issue will be helpful . >>>>> >>>>> Thanks >>>>> Pragya Nand >>>>> >>>>> >>>>> >>>>> >>>> >>>> -- >>>> Best regards >>>> Stanislav Zaikin >>>> >>>> >>>> >>>> >>> >>> >>> >> >> >> > > -- > Best regards > Stanislav Zaikin > > > >
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