From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean Baptiste Favre Subject: Re: PCI passthrough issue Date: Tue, 01 Feb 2011 13:17:19 +0100 Message-ID: <4D47F9CF.2040107@jbfavre.org> References: <4D2E28C5.30203@jbfavre.org> <4D2EE1DE.5070006@jbfavre.org> <4D2F5009.2090701@jbfavre.org> <20110113201922.GA20494@dumpdata.com> <4D2F6431.8030606@jbfavre.org> <20110114145350.GB7371@dumpdata.com> <4D30DC5A.9080303@jbfavre.org> <4D340504.7020203@jbfavre.org> <4D344AF4.80301@jbfavre.org> <4D3AB003.3040603@jbfavre.org> <20110127202755.GA4194@dumpdata.com> <4D41E7EE.4060502@jbfavre.org> <4D42E520.9020107@jbfavre.org> <1296560086.13091.131.camel@zakaz.uk.xensource.com> Reply-To: xen-devel@lists.xensource.com Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1296560086.13091.131.camel@zakaz.uk.xensource.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 Hello Ian, Le 01/02/2011 12:34, Ian Campbell a =C3=A9crit : > On Fri, 2011-01-28 at 15:47 +0000, Jean Baptiste Favre wrote: > > Hello, > > I made some more tests today, still with 2.6.37 32bits kernel from > > Debian experimental, with various memory allocation value. > > > > For each test, I make ping on my gateway with various packet size: > > ping -s15 10.0.0.1 > > ping -s85 10.0.0.1 > > ping -s86 10.0.0.1 > > ping -s150 10.0.0.1 > > > > Results bellow: > > > > - less than 256mb: works > > - between 256 and 512mb: ping greater than 85 bytes does not work > > - more than 512mb: works > > > > I'm lost... > > Me too, this really is the most inexplicable set of symptoms... > > Does it work correctly with any other guest kernel, e.g. the > xen/stable-2.6.32.x branch from xen.git or maybe one of the old-style > Xen kernels? I'm compiling 2.6.32 kernel from Jeremy's GIT repos to check that. > The network device in use is one of the Intel NICs below? Any luck just > passing through that one device without all the others? > > Previously you mentioned using a Marvell NIC, so I guess the failure is > independent of the NIC type? I made all tests with Marvell NIC (driver sky2). I don't know if the same behaviour occurs with another NIC type. I'll try with an Intel one (I've a dual port Intel NIC, so I could passthrough only one port) > Your userspace is still OpenWRT in these most recent tests? Is that som= e > sort of busybox based thing? Can you try with e.g. a regular Debian > guest userspace to rule out any funnyness from that end? I made tests with both OpenWRT and Debian Squeeze. Had problems to compile OpenWRT kernel in 64bits :) I tested Debian Squeeze with 2.6.37 kernel from experimental (because of Xen PCI Frontend integration. Not sure it has been backported into 2.6.32= ). I will test with Jeremy's 2.6.32 kernel (see above). As a conclusion, last results are from Debian Squeeze with 2.6.37 and that's why I wrote on debian-kernel maillist :) > If you restrict dom0 to >256MB but <512MB (using dom0_mem=3D on hypervi= sor > command line) does the NIC work correctly in non-passedthrough form? My Xen hypervisor commandline is as follow: placeholder dom0_mem=3D256M dom0_max_vcpus=3D1 dom0_vcpus_pin loglvl=3Dal= l guest_loglvl=3Dall com1=3D115200,8n1 console=3Dcom1 Everything works great without passthrough, but my dom0 is 64bits which may explain that (I do have this strange behaviour only with 32bits kernels). I did not tried changing dom0_mem param. > Similarly does the kernel running native with mem=3D cause the failure? Not sure I understand what you mean here. BTW, I'm preparing a set of automatic tests with different memory values. That will be: * loop for each mem value - set memory in domU configfile - starting domU with 128Mb memory - rc.local will ping my gateway with different packet size, store result in file - halt domU * end of loop * Check results :-/ > Bit of a long shot but are you able to try a 4.0.2-rc hypervisor+tools > and/or a 4.1.0-rc setup (not branched yet so still in xen-unstable.hg)? I can eventually try it, but after my looong test list :) > Is the 10.0.0.1 address you are testing against a VM on the same host o= r > some sort of external entity? It's my gateway (for the history, WRT54GL with OpenWRT). Regards, JB