January 2019 - Users - libvirt List Archives

[libvirt-users] assigning PCI addresses with bus > 0x09
by Riccardo Ravaioli 04 Jan '19

04 Jan '19

Hi, My goal is to assign PCI addresses to a number of devices (network interfaces, disks and PCI devices in PCI-passthrough) without delegating to libvirt the generation of those values. This should give me more control and for sure more predictability over the hardware configuration of a virtual machine and consequently the name of the interfaces in it. I'm using libvirt 4.3.0 to create qemu/KVM virtual machines running Linux (Debian Stretch). So, for every device of the type mentioned above, I add this line: <address type='pci' domain='0x0000' bus='0x__' slot='0x__' function='0x0'/>, ... with values from 00 to ff in the bus field, and from 00 to 1f in the slot field, as described in the documentation. Long story short, I noticed that as soon as I assign values > 0x09 to the bus field, the serial console hangs indefinitely, in both Debian and Ubuntu. The VM seems to be started correctly and its state is "running"; in the XML file created by libvirt, I see all controllers from 0 the largest bus value I assigned, so everything from that side seems ok. What am I missing here? Thanks! Riccardo

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[libvirt-users] guest runs into watch dog reset
by b f31415 04 Jan '19

04 Jan '19

I'm spinning up a guest, using virt-install. i'm passing the guest a single vcpu and many network interfaces. On the guest side all the interfaces are initially in the down state. I've notice then when I manually bring a specific one of these interfaces up (eg the 64th interface), the guest system hangs. Doing an "strace ifconfig etX up", it looks like the system hangs when doing the ioctl to bring the interface up. This guest is 18.04. Host is 16.04. Are there any qemu/virt commands i can run from the host which would provide me a better understanding as to why the guest gets into this hung state? If I pass two vcpu, I don't suffer from this hang issue. Thanks

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[libvirt-users] avoiding PCI bus 8 / using PCI function / virt-install
by b f31415 02 Jan '19

02 Jan '19

I’m using virt-install to spin up VMs. At times I have a need to spin up VMs which have 100s of interfaces. I ran into the PCI issue mentioned in this previous thread based on how virt-install assigns PCI addresses to interfaces: https://www.redhat.com/archives/libvirt-users/2018-December/msg00064.html Using the info mention there I was able to part hand / part sw re-write an XML where I would remove PCI bus references above the value of 8 and re-address the per interface PCI info to use the function field (I don’t need hot pluggable). But the process I’ve built is brittle. Wondering what options i might have to better deal with this PCI issue. Is there a way to tell virt-install, when building the info it passes to qemu, to use the function field during the PCI assignment process so as to support many more interfaces before hitting the PCI bus == 8 issue? If not, is there a way with one of the virt command line tools to create the XML (with the PCI addresses specified) so that I can process that XML and re-write the PCI addressing values? Right now the only way I’ve been able to get that detailed XML file is to 1) virt-install and let the VM begin the boot process and then do a 2) virsh dumpxml and then 3) virsh destroy/undefine that VM, 4) modify the XML and then 5) virsh create ./modified.xml. Is there a cleaner way to do this? Thanks

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[libvirt-users] Network filters with clean-traffic not working on Debian Stretch
by fatal 02 Jan '19

02 Jan '19

Hello, I'm recently stumbled over the libvirt network filter capabilities and got pretty excited. Unfortunately I'm not able to get the the "clean-traffic" filterset working. I'm using a freshly installed Debian Stretch with libvirt, qemu and KVM. My config snippet looks as follows: sudo virsh edit <VM> [...] <interface type='bridge'> <mac address='52:54:00:0c:14:07'/> <source bridge='br0'/> <model type='virtio'/> <filterref filter='clean-traffic'> <parameter name='IP' value='10.10.1.2'/> </filterref> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <interface type='bridge'> <mac address='52:54:00:0c:24:17'/> <source bridge='br1'/> <model type='virtio'/> <filterref filter='clean-traffic'> <parameter name='IP' value='172.16.1.2'/> </filterref> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> [...] I restarted the VM from within the VM, did a "virsh reboot <VM>", restarted libvirtd and even did a reboot of the host - just to be sure. Unfortunately neither "iptables -L" nor "ebtables --list" show any entries added by libvirt. Also omitting the "parameter name='IP'" part didn't change anything. There are no error messages in /var/log/syslog nor in /var/log/libvirt/qemu/<VM> My main references were: https://libvirt.org/firewall.html https://libvirt.org/formatnwfilter.html https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/ht… https://www.berrange.com/posts/2011/10/03/guest-mac-spoofing-denial-of-serv… Any help really would be much appreciated! Thanks a lot! Sam

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