Re: [libvirt] [Xen-devel] Setting devid for emulated NICs (Xen 4.3.1 / libvirt 1.2.0) using libxl driver

On Tue, 2013-12-17 at 17:34 +0100, Stefan Bader wrote: > Using virt-manager "hypervisor default" type: > > <interface type='bridge'> > <mac address='00:16:3e:5e:09:9d'/> > <source bridge='br0'/> > <script path='vif-bridge'/> > </interface> > > This causes the qemu call to have "-net none" which removes PXE boot > abilities. A linux kernel has network through the xen pv-driver. > > Changing in virt-manager to "e1000" type: > > <interface type='bridge'> > <mac address='00:16:3e:5e:09:9d'/> > <source bridge='br0'/> > <script path='vif-bridge'/> > <model type='e1000'/> > </interface> > > This currently (Xen 4.3.1 + libvirt 1.2.0) fails and the qemu arguments > in the log look suspicious: > -device e1000,id=nic-1,netdev=net-1,mac=00:16:3e:5e:09:9d > -netdev type=tap,id=net-1,ifname=vif1.-1-emu,script=no,downscript=no > > Looking through git I found ba64b97134a6129a48684f22f31be92c3b6eef96 > libxl: Allow libxl to set NIC devid Is that a libvirt commit? Not seeing it in xen.git.

Might this libxl fix be relevant: commit 5420f26507fc5c9853eb1076401a8658d72669da Author: Jim Fehlig <jfehlig(a)suse.com&gt; Date: Fri Jan 11 12:22:26 2013 +0000 libxl: Set vfb and vkb devid if not done so by the caller Other devices set a sensible devid if the caller has not done so. Do the same for vfb and vkb. While at it, factor out the common code used to determine a sensible devid, so it can be used by other libxl__device_*_add functions. Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; Acked-by: Ian Campbell <ian.campbell(a)citrix.com&gt; Committed-by: Ian Campbell <ian.campbell(a)citrix.com&gt; and a follow up in dfeccbeaa. Although the comment implies that nic's were already correctly assigning a devid if the caller specified -1, so I don't know why it doesn't work for you :-(

> > which removes a line that sets the devid of new NICs. I assume the comment > says (sorry I always seem to get confused reading it) that devid should > be auto-set by the libxl library provided by Xen. Correct. > But I could not find where that would be done. I expect the above commits have pointed you to the right line, but the code should be quite near the top of libxl__device_nic_add in libxl.c > Even the xl command implementation sets it > explicitly. The caller is also allowed to do this if it cares what number is used. > libxl_device_nic_init sets it to -1 which would explain the > wrong qemu arguments above. Right, libxl_device_nic_init sets everything to "the defaults please" and __device_nic_add will instantiate any defaults which the application didn't supply. > For testing I re-added the following after the libxlMakeNic call: > > --- libvirt-1.2.0.orig/src/libxl/libxl_conf.c 2013-12-11 17:04:17.000000000 +0 > +++ libvirt-1.2.0/src/libxl/libxl_conf.c 2013-12-16 19:08:46.830016646 +0 > @@ -907,6 +907,8 @@ libxlMakeNicList(virDomainDefPtr def, l > for (i = 0; i < nnics; i++) { > if (libxlMakeNic(l_nics[i], &x_nics[i])) > goto error; > + if (x_nics[i].devid < 0) > + x_nics[i].devid = i; > } > > d_config->nics = x_nics; > > And with that I get a working PXE boot when I set the device type > in the config. (Side note that I think not using a type defaults to > rtl8139 in the old xend driver. Maybe this should be the same for the > xl driver). > I am not sure how the right fix for it should look like as I am unsure > which part was supposed to set the devid. Just right now it does not > seem to be done. > > -Stefan > _______________________________________________ Xen-devel mailing list Xen-devel(a)lists.xen.org http://lists.xen.org/xen-devel