From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Baptiste Favre Subject: Re: PCI passthrough issue Date: Thu, 13 Jan 2011 21:44:33 +0100 Message-ID: <4D2F6431.8030606@jbfavre.org> References: <4D2DDD4D.9090503@jbfavre.org> <20110112172620.GB11522@dumpdata.com> <4D2DE889.4040604@jbfavre.org> <20110112183242.GA23125@dumpdata.com> <4D2E0A02.2020606@jbfavre.org> <20110112214034.GA5833@dumpdata.com> <4D2E2149.1010002@jbfavre.org> <4D2E28C5.30203@jbfavre.org> <4D2EE1DE.5070006@jbfavre.org> <4D2F5009.2090701@jbfavre.org> <20110113201922.GA20494@dumpdata.com> Reply-To: xen-devel@lists.xensource.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20110113201922.GA20494@dumpdata.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Le 13/01/2011 21:19, Konrad Rzeszutek Wilk a =E9crit : > On Thu, Jan 13, 2011 at 08:18:33PM +0100, Jean Baptiste Favre wrote: >> Hello, >> My dom0 is back and I performed some more tests. >> >> I told in my first mail that ping works. Indeed it works, but not alwa= ys: >> # ping -c2 10.0.0.1 >> PING 10.0.0.1 (10.0.0.1): 56 data bytes >> 64 bytes from 10.0.0.1: seq=3D0 ttl=3D64 time=3D0.846 ms >> 64 bytes from 10.0.0.1: seq=3D1 ttl=3D64 time=3D0.824 ms >> >> --- 10.0.0.1 ping statistics --- >> 2 packets transmitted, 2 packets received, 0% packet loss >> round-trip min/avg/max =3D 0.824/0.835/0.846 ms >> # ping -c2 -s60 10.0.0.1 >> PING 10.0.0.1 (10.0.0.1): 60 data bytes >> 68 bytes from 10.0.0.1: seq=3D0 ttl=3D64 time=3D0.819 ms >> 68 bytes from 10.0.0.1: seq=3D1 ttl=3D64 time=3D0.807 ms >> >> --- 10.0.0.1 ping statistics --- >> 2 packets transmitted, 2 packets received, 0% packet loss >> round-trip min/avg/max =3D 0.807/0.813/0.819 ms >> >> Increasing packet size is ok until this one: >> # ping -c2 -s85 10.0.0.1 >> PING 10.0.0.1 (10.0.0.1): 85 data bytes >> 93 bytes from 10.0.0.1: seq=3D0 ttl=3D64 time=3D0.823 ms >> 93 bytes from 10.0.0.1: seq=3D1 ttl=3D64 time=3D0.816 ms >> >> --- 10.0.0.1 ping statistics --- >> 2 packets transmitted, 2 packets received, 0% packet loss >> round-trip min/avg/max =3D 0.816/0.819/0.823 ms >> root@OpenWrt:/# ping -c2 -s86 10.0.0.1 >> PING 10.0.0.1 (10.0.0.1): 86 data bytes >> >> --- 10.0.0.1 ping statistics --- >> 2 packets transmitted, 0 packets received, 100% packet loss >> >> As you see, packet size seems to be limited in a way. From another >> machine on the same LAN I can do ping -s1500 without any problem. >=20 > One thing that I just thought (which I keep on forgetting to do). > You did set 'iommu=3Dsoft' in your Linux guest, right? Tought I told it in my previou smails. Sorry to missed it: On my dom0: $ cat /proc/cmdline placeholder root=3D/dev/mapper/system-root ro console=3Dhvc0 earlyprintk=3D= xen nomodeset xen-pciback.permissive xen-pciback.hide=3D(04:00.0) pci=3Dresource_alignment=3D04:00.0 quiet Xen hypervisor options are: # xm dmesg (XEN) Xen version 4.0.1 (Debian 4.0.1-1) (waldi@debian.org) (gcc version 4.4.5 20100824 (prerelease) (Debian 4.4.4-11) ) Fri Sep 3 15:38:12 UTC 2= 010 (XEN) Bootloader: GRUB 1.98+20100804-11 (XEN) Command line: placeholder dom0_mem=3D256M dom0_max_vcpus=3D1 dom0_vcpus_pin loglvl=3Dall guest_loglvl=3Dall com1=3D115200,8n1 console=3D= com1 OpenWRT domU config file is: $ cat /etc/xen/auto/openwrt.cfg kernel =3D '/home/domU/wrt/openwrt-x86-xen_domu-vmlinuz' root =3D '/dev/xvda2 rw' memory =3D '256' vcpus =3D '1' cpus =3D '1' localtime =3D 0 serial =3D 'pty' disk =3D ['file:/home/domU/wrt/openwrt-x86-xen_domu-combined-ext4.img,xvd= a,w'] #vif =3D [ 'bridge=3Dbr-wan, mac=3D00:16:3E:01:00:64, vifname=3Dwrt-100.e= th1' ] on_poweroff =3D 'destroy' on_reboot =3D 'restart' on_crash =3D 'restart' extra =3D "iommu=3Dsoft swiotlb=3Dforce console=3Dhvc0 xencons=3Dtty" pci =3D [ '04:00.0' ] name =3D 'openwrt' hostname =3D 'openwrt.clichy.jbfavre.org' >> So I think I hit a bug. Either it's Xen related, or Debian (through >> debian kernel version). Now the question is: how can I determine which >> part is responsible ? >=20 > What does tcpdump tell you when you try to send it at -s86? I can see echo requests coming in on my gateway, replies going back but replies are never received on the domU. Regards, JB