On 2011-06-17 22:31, Georg Hopp wrote: > Am 17.06.2011 09:29:41 schrieb(en) Jan Kiszka: >> On 2011-06-17 09:10, Georg Hopp wrote: >> > Jan Kiszka <jan.kiszka <at> web.de> writes: >> >> >> >> On 2011-06-10 05:08, Amos Kong wrote: >> >>> host kernel: 2.6.39-rc2+ >> >>> qemu-kvm : 05f1737582ab6c075476bde931c5eafbc62a9349 >> >>> >> >>> (gdb) r -monitor stdio -m 800 ~/RHEL-Server-6.0-64-virtio.qcow2 >> -snapshot >> > -device >> >> virtio-net-pci,netdev=he -netdev tap,vhost=on,id=he >> >>> >> >> >> >> I already came across that symptom in a different context. Fixed by >> the >> >> patch below. >> >> >> >> However, the real issue is related to an upstream cleanup of the >> >> virtio-pci build. That reveals some unneeded build dependencies in >> >> qemu-kvm. Will post a fix. >> >> >> >> Jan >> > >> > FYI >> > >> > I encountered the same problem and applied the patch. >> > >> > Well this results in the following error while starting the guest: >> > >> > qemu-system-x86_64: unable to start vhost net: 38: >> > falling back on userspace virtio >> > >> > and i have no network at all. I will disable vhost=on for now. >> >> Hmm, works fine for me. The vhost-net module is loaded (though I got a >> different message when I forgot to load it)? >> >> Jan >> > > Generally it works for me until git revision b2146d8bd. You mean including that commit, right? > > I have compiled vhost-net directly in my kernel so a have definetly not > forgotten to load it... > As i use gentoo i made an ebuild that installes exactly this revision. > If i find the time to do some debugging i will do so, but actually i am > very busy with my job > family and the use of kvm is just a sparetime thing. :D > > If it would be of some help i can set a breakpoint just before the path > and see what > causes the message. Let's start with double-checking that you are on ce5f0a588b, did a make clean && make, and then actually used that result. I suspect an inconsistent build as ce5f0a588b makes the difference between ENOSYS (38) and working vhost support here. Jan
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