From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: PCI passthrough issue Date: Wed, 12 Jan 2011 11:36:47 -0500 Message-ID: <20110112163647.GB10863@dumpdata.com> References: <4D2DCB09.5010703@jbfavre.org> <20110112154344.GA28780@dumpdata.com> <4D2DCE8F.3060504@jbfavre.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <4D2DCE8F.3060504@jbfavre.org> 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 On Wed, Jan 12, 2011 at 04:53:51PM +0100, Jean Baptiste Favre wrote: > Hello Konrad, >=20 > Le 12/01/2011 16:43, Konrad Rzeszutek Wilk a =E9crit : > > On Wed, Jan 12, 2011 at 04:38:49PM +0100, Jean Baptiste Favre wrote: > >> Hello, > >> I'm facing a strange issue with network card PCI passthrough on my > >> openwrt test domU. > >> > >> - With network PCI passthrough, DNS lookup failed for some domains > >> (exemple, google.com) but not for other (free.fr my ISP, or my domai= n > >> jbfavre.org). I can ping an IP address without any problem. > >=20 > > Do you have "both" (so PCI passthrough and the Xen network driver) > > in the guest? If so, have you tried eliminating the xen network drive= r > > to see if it is just a routing issue? > Have not tried to eliminate xen network driver. Think I have both drive= rs. >=20 > My kernel .config looks like: > $ grep XEN build_dir/linux-x86_xen_domu/linux-2.6.37/.config > CONFIG_XEN=3Dy > # CONFIG_XEN_PRIVILEGED_GUEST is not set > CONFIG_XEN_PVHVM=3Dy > CONFIG_XEN_MAX_DOMAIN_MEMORY=3D128 > CONFIG_XEN_SAVE_RESTORE=3Dy > CONFIG_PCI_XEN=3Dy > CONFIG_XEN_PCIDEV_FRONTEND=3Dy > CONFIG_XEN_BLKDEV_FRONTEND=3Dy > CONFIG_XEN_NETDEV_FRONTEND=3Dy > CONFIG_HVC_XEN=3Dy > CONFIG_XEN_BALLOON=3Dy > CONFIG_XEN_SCRUB_PAGES=3Dy > CONFIG_XEN_DEV_EVTCHN=3Dy > CONFIG_XENFS=3Dy > CONFIG_XEN_COMPAT_XENFS=3Dy > CONFIG_XEN_SYS_HYPERVISOR=3Dy > # CONFIG_XEN_PLATFORM_PCI is not set > CONFIG_SWIOTLB_XEN=3Dy >=20 > So, I should remove CONFIG_XEN_NETDEV_FRONTEND ? No. You can just do 'ifconfig down' whatever your Xen netfront NIC is. .. but. >=20 > > What does your routing table look like? Your IP table? > My routing table is pretty clean, nothing strange here > # route -n > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use > Iface > 10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0 > br-wan > 0.0.0.0 10.0.0.1 0.0.0.0 UG 0 0 0 > br-wan Ok, then the idea that the Xen networking driver and the PCI passthrough = send packets over is not the way.. So ignore about the Xen networking part. >=20 > >> - Starting domU as a "normal" (ie without PCI passthrough), no probl= em. > >> > >> > >> As far as I can say, domU is not the root cause. I really think this= is > >> related to PCI passsthrough. This seems to be related to packet leng= th. > >=20 > > Then that would imply the MTU is not set right.=20 > Already checked it: 1500 :) Ok. Next thing, did you try to disable the rx/tx checksumming? If you connect the Ethernet cable for this 'br-wan' device to another mac= hine (so you could set it up as bridge and just let it pass through packets an= d sniff the data) what do the packets look like? What happens if the PCI passthrough device is not under the ownership of = a bridge? What then? You wouldn't have any bridge firewall code in?