September 2018 - Users - libvirt List Archives

[libvirt-users] bridge / ubuntu / no arp reply
by François Chenais 15 Oct '26

15 Oct '26

Hello I'm trying to setup a bridged guest on an ubuntu 13.10 but it doesn't work. (Everything is ok with NAT) Network sniffing shows that arp replies don't come back to the guest. Test 1 ------ Guest : ping host_bridge_ip (ok) Test 2 ------ Guest: ping other_lan_host (KO) other_lan_host - receives arp who-is request - sends arp reply - arp -a shows the guest macaddr => Guest doesn't receive reply Test 3 ------ other_lan_host ping the Guest (KO) - arp -a shows "incomplete" addr - Guest receives nothing On Host ------- network tcpdump on bridge or vnet interfaces shows request but no reply ... Thanks in advance for help or ideas François

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[libvirt-users] [virtual interface] detach interface during boot succeed with no changes
by Yalan Zhang 08 Sep '22

08 Sep '22

Hi guys, when I detach an interface from vm during boot (vm boot not finished), it always fail. I'm not sure if there is an existing bug. I have confirmed with someone that for disk, there is similar behavior, if this is also acceptable? # virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 2; virsh detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh dumpxml rhel7.2 |grep /interface -B9 Domain rhel7.2 destroyed Domain rhel7.2 started Interface detached successfully <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </controller> <interface type='network'> <mac address='52:54:00:98:c4:a0'/> <source network='default' bridge='virbr0'/> <target dev='vnet0'/> <model type='rtl8139'/> <alias name='net0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> When I detach after the vm boot, expand the sleep time to 10, it will succeed. # virsh destroy rhel7.2; virsh start rhel7.2 ;sleep 10; virsh detach-interface rhel7.2 network 52:54:00:98:c4:a0; sleep 2; virsh dumpxml rhel7.2 |grep /interface -B9 Domain rhel7.2 destroyed Domain rhel7.2 started Interface detached successfully ------- Best Regards, Yalan Zhang IRC: yalzhang Internal phone: 8389413

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[libvirt-users] Add Virtlyst to the list of libvirt users
by Daniel Nicoletti 23 Sep '20

23 Sep '20

Hi, I've just released v1.0.0 of Virtlyst[1] a web tool to manage VMs using Qt/C++/Cutelyst https://dantti.wordpress.com/2018/04/19/announcing-virtlyst-a-web-interface… Thanks. 1 - https://github.com/cutelyst/Virtlyst -- Daniel Nicoletti KDE Developer - http://dantti.wordpress.com

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[libvirt-users] Question about disabling UFO on guest
by Bao Nguyen 05 Aug '20

05 Aug '20

Hello everyone, I would like to ask a question regarding to disable UFO of virtio vNIC in my guest. I have read the document at https://libvirt.org/formatdomain.html *host* The csum, gso, tso4, tso6, ecn and ufo attributes with possible values on and off can be used to turn off host offloading options. By default, the supported offloads are enabled by QEMU. *Since 1.2.9 (QEMU only)* The mrg_rxbuf attribute can be used to control mergeable rx buffers on the host side. Possible values are on (default) and off. *Since 1.2.13 (QEMU only)* *guest* The csum, tso4, tso6, ecn and ufo attributes with possible values on and off can be used to turn off guest offloading options. By default, the supported offloads are enabl ed by QEMU. *Since 1.2.9 (QEMU only)* Then I disabled UFO on my vNIC on guest as the following configuration <devices> <interface type='network'> <source network='default'/> <target dev='vnet1'/> <model type='virtio'/> <driver name='vhost' txmode='iothread' ioeventfd='on' event_idx='off' queues='5' rx_queue_size='256' tx_queue_size='256'> *<host gso='off' ufo='off' />* *<guest ufo='off'/>* </driver> </interface> </devices> Then I reboot my node to get the change effect and it works. However, can I disable the UFO without touching the host OS? or it always has to disable on both host and guest like that? Thanks, Brs, Natsu

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[libvirt-users] Libvirt access control drivers
by Anastasiya Ruzhanskaya 21 Nov '18

21 Nov '18

Hello! According to the documentation access control drivers are not in really "good condition". There is a polkit, but it can distinguish users only according the pid. However, I have met some articles about more fine-grained control and about selinux drivers for libvirt? So, what is the status now? Should I implement something by myself if I want access based on login, are their instructions how to write these drivers or there is smth already?

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[libvirt-users] live migration via unix socket
by David Vossel 12 Oct '18

12 Oct '18

Hey, Over in KubeVirt we're investigating a use case where we'd like to perform a live migration within a network namespace that does not provide libvirtd with network access. In this scenario we would like to perform a live migration by proxying the migration through a unix socket to a process in another network namespace that does have network access. That external process would live on every node in the cluster and know how to correctly route connections between libvirtds. virsh example of an attempted migration via unix socket. virsh migrate --copy-storage-all --p2p --live --xml domain.xml my-vm qemu+unix:///system?socket=destination-host-proxy-sock In this example, the src libvirtd is able to establish a connection to the destination libvirtd via the unix socket proxy. However, the migration-uri appears to require either tcp or rdma network connection. If I force the migration-uri to be a unix socket, I receive an error [1] indicating that qemu+unix is not a valid transport. Technically with qemu+kvm I believe what we're attempting should be possible (even though it is inefficient). Please correct me if I'm wrong. Is there a way to achieve this migration via unix socket functionality this using Libvirt? Also, is there a reason why the migration uri is limited to tcp/rdma Thanks! - David [1] https://github.com/libvirt/libvirt/blob/master/src/qemu/qemu_migration.c#L2…

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[libvirt-users] how "safe" is blockcommit ?
by Lentes, Bernd 12 Oct '18

12 Oct '18

Hi, currently i'm following https://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit. I 'm playing around with it and it seems to be quite nice. What i want is a daily consistent backup of my image file of the guest. I have the idea of the following procedure: - Shutdown the guest (i can live with a downtime of a few minutes, it will happen in the night). And i think it's the only way to have a real clean snapshot - create a snapshot with snapshot-create-as: snapshot-create-as guest testsn --disk-only - start the guest again. Changes will now go into the overlay, as e.g. inserts in a database - rsync the base file to a cifs server. With rsync not the complete, likely big file is transferred but just the delta - blockcommit the overlay: blockcommit guest /path/to/testsn --active --wait --verbose --pivot - delete the snapshot: snapshot-delete guest --snapshotname testsn --metadata - remove the overlay Is that ok ? How "safe" is blockcommit on a running guest ? It's possible that during the rsync, when the guest is running, some inserts are done in a database. Is it safe to copy the new sectors (i assume that's what blockcommit does) under a running database ? Or is it only safe doing blockcommit on a stopped guest ? Thanks for any answer. Bernd P.S. Is the same procedure possible when the guest disk(s) reside directly in a plain logical volume, without a file system in-between ? -- Bernd Lentes Systemadministration Institut für Entwicklungsgenetik Gebäude 35.34 - Raum 208 HelmholtzZentrum münchen [ mailto:bernd.lentes@helmholtz-muenchen.de | bernd.lentes(a)helmholtz-muenchen.de ] phone: +49 89 3187 1241 fax: +49 89 3187 2294 [ http://www.helmholtz-muenchen.de/idg | http://www.helmholtz-muenchen.de/idg ] wer Fehler macht kann etwas lernen wer nichts macht kann auch nichts lernen Helmholtz Zentrum Muenchen Deutsches Forschungszentrum fuer Gesundheit und Umwelt (GmbH) Ingolstaedter Landstr. 1 85764 Neuherberg www.helmholtz-muenchen.de Aufsichtsratsvorsitzende: MinDir'in Baerbel Brumme-Bothe Geschaeftsfuehrer: Prof. Dr. med. Dr. h.c. Matthias H. Tschoep, Heinrich Bassler, Dr. rer. nat. Alfons Enhsen Registergericht: Amtsgericht Muenchen HRB 6466 USt-IdNr: DE 129521671

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[libvirt-users] live migration and config
by Dmitry Melekhov 04 Oct '18

04 Oct '18

Hello! After some mistakes yesterday we ( me and my colleague ) think that it will be wise for libvirt to check config file existence on remote side and through error if not, before migrating, otherwise migration will fail and VM fs can be damaged, because it is sort of remove of power plug... We missed twice yesterday :-( Could you tell me is there already such option or any plans to implement this? Thank you!

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[libvirt-users] This QEMU doesn't support the LSI 53C895A SCSI controller
by Gionatan Danti 02 Oct '18

02 Oct '18

Hi all, trying to edit a domain xml to enable an LSI SCSI controller I get the following error: error: unsupported configuration: This QEMU doesn't support the LSI 53C895A SCSI controller It is my understanding that the error is raised due to RedHat disabling this controller in its own qemu-kvm builds. This seems an unfortunate decision, as it makes harder to migrate from VMWare (which uses LSI SCSI and SAS adapters) to RH+KVM. Can anyone elaborate on this decision? It is possible to enable LSI controller support in RedHat 7.x? Should I open a BZ against it? Thanks. -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: g.danti(a)assyoma.it - info(a)assyoma.it GPG public key ID: FF5F32A8

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[libvirt-users] libvirt reported capabilities doesn't match /proc/cpuinfo while the model does match
by Braiam Peguero 01 Oct '18

01 Oct '18

Hi, According to virsh capabilities I only have the following cpu features: <cpu> <arch>x86_64</arch> <model>IvyBridge-IBRS</model> <vendor>Intel</vendor> <microcode version='32'/> <topology sockets='1' cores='4' threads='1'/> <feature name='ds'/> <feature name='acpi'/> <feature name='ss'/> <feature name='ht'/> <feature name='tm'/> <feature name='pbe'/> <feature name='dtes64'/> <feature name='monitor'/> <feature name='ds_cpl'/> <feature name='vmx'/> <feature name='smx'/> <feature name='est'/> <feature name='tm2'/> <feature name='xtpr'/> <feature name='pdcm'/> <feature name='pcid'/> <feature name='osxsave'/> <feature name='arat'/> <feature name='ssbd'/> <feature name='xsaveopt'/> <feature name='invtsc'/> <pages unit='KiB' size='4'/> <pages unit='KiB' size='2048'/> </cpu> Meanwhile, cpuinfo reports the following: flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm cpuid_fault epb pti ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms xsaveopt dtherm ida arat pln pts flush_l1d bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf This results on my cpu being detected, if I allow host copy, as AMD chip and the guest becomes unbearably slow. The model of the host cpu is correct. I'm using Debian testing/unstable. Compiled against library: libvirt 4.7.0 Using library: libvirt 4.7.0 Using API: QEMU 4.7.0 Running hypervisor: QEMU 2.12.0 -- Braiam

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