October 2022 - 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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WinServer2016 guest no mouse in VirtManager
by John McInnes 03 Feb '23

03 Feb '23

Hi! I recently converted several Windows Server VMs from HyperV to libvirt/KVM. The host is running openSUSE Leap 15.3. I used virt-v2v and I installed virtio drivers on all of them and it all went well - except for one VM. The mouse does not work for this VM in VirtualMachineManager. There is no cursor and no response. There are no issues showing in Windows Device Manager. The mouse shows up as a PS/2 mouse. Interestingly if I RDP into this VM using Microsoft Remote Desktop the mouse works fine. Any ideas? ---- John McInnes jmcinnes /\T svt.org

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Testing DKIM handling
by dberrange＠yahoo.com 16 Dec '22

16 Dec '22

Testing DKIM handling RH mail servers

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Libvirt slow after a couple of months uptime
by André Malm 21 Nov '22

21 Nov '22

Hello, I have some issues with libvirtd getting slow over time. After a fresh reboot (or systemctl restart libvirtd) virsh list / virt-install is fast, as expected, but after a couple of months uptime they both take a significantly longer time. Virsh list takes around 3 seconds (from 0.04s on a fresh reboot) and virt-install takes over a minute (from around a second). Running strace on virsh list it seems to get stuck in a loop on this: poll([{fd=5<socket:[173169773]>, events=POLLOUT}, {fd=6<anon_inode:[eventfd]>, events=POLLIN}], 2, -1) = 2 ([{fd=5, revents=POLLOUT}, {fd=6, revents=POLLIN}]) While restarting libvirtd fixes it a restart takes around 1 minute where ebtables rules etc are recreated and it does interrupt the service. What could cause this? How would I troubleshoot this? I'm running Ubuntu 22.04 / libvirt 8.0.0 with 70 active VM’s on a 16/32 core machine with 256GB of ram, CPU is below 50% usage at all times, memory below 50% usage and swap 0% usage. Thanks, André

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domain_qemu_agent_command($domain,$cmd,$timeout,$flags)
by Simon Fairweather 16 Nov '22

16 Nov '22

Should there be a way to suppress errors using the flags? error : qemuDomainAgentAvailable:8411 : Guest agent is not responding: QEMU guest agent is not connected Or is there a libvirt function to check connection status or another way?

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Predictable and consistent net interface naming in guests
by Edward Haas 02 Nov '22

02 Nov '22

Hi Igor and Laine, I would like to revive a 2 years old discussion [1] about consistent network interfaces in the guest. That discussion mentioned that a guest PCI address may change in two cases: - The PCI topology changes. - The machine type changes. Usually, the machine type is not expected to change, especially if one wants to allow migrations between nodes. I would hope to argue this should not be problematic in practice, because guest images would be made per a specific machine type. Regarding the PCI topology, I am not sure I understand what changes need to occur to the domxml for a defined guest PCI address to change. The only think that I can think of is a scenario where hotplug/unplug is used, but even then I would expect existing devices to preserve their PCI address and the plug/unplug device to have a reserved address managed by the one acting on it (the management system). Could you please help clarify in which scenarios the PCI topology can cause a mess to the naming of interfaces in the guest? Are there any plans to add the acpi_index support? [1] https://bugzilla.redhat.com/show_bug.cgi?id=1874096#c15 Thank you, Edy.

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hook script for changing disk definition before guest start
by Gionatan Danti 31 Oct '22

31 Oct '22

Hi all, due to this [1] I am trying to change a guest's disk definition from "pool volume" to "file" via hook scripts. This seems an easy task via virsh detach-disk and virsh attach-disk, but virsh can not be called inside libvirt hook scripts. The best approach would be to change the disk definition right when a disk is attached, but I can not find any event calling a hook script when a disk is attache/detached. Do you have any suggestion short of monitoring the directory /etc/libvirt/qemu itself for changed files? Thanks. [1] https://github.com/cockpit-project/cockpit-machines/issues/815 -- 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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Re: How to check tap device for sndbuf when I set sndbuf=0 in the interface xml
by Yalan Zhang 31 Oct '22

31 Oct '22

cc libvirt-users for more inputs Hi, I'm trying to find out how to check sndbuf for a tap device, could you please help to check it? In kernel 2.6.18, the tap device's default sndbuf is 1MB. There is a RFE bug[1] and patch[2] to introduce the option below in libvirt to adjust the sndbuf. <tune> <sndbuf>1600</sndbuf> </tune> It is said in the patch[2] that when we set sndbuf=0, we actually set it to 0xffffffff. How to check if it is set successfully? I have checked the below files, the value didn't change after I start a vm with sndbuf=0 # grep . /proc/sys/net/core/*mem_default /proc/sys/net/core/rmem_default:212992 /proc/sys/net/core/wmem_default:212992 And from the doc[3]: "The default value is set by the /proc/sys/net/core/wmem_default file and the maximum allowed value is set by the /proc/sys/net/core/wmem_max file." Current kernel 5.14.0-177.el9 has some updates about sndbuf: # cat /proc/sys/net/core/wmem_default 212992 # cat /proc/sys/net/core/wmem_max 212992 Thank you! [1] Bug 665293 <https://bugzilla.redhat.com/show_bug.cgi?id=665293> - RFE: Allow setting size of send buffer per TAP device in QEMU driver [2] https://listman.redhat.com/archives/libvir-list/2011-January/032763.html [3] https://man7.org/linux/man-pages/man7/socket.7.html Yalan

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Video device model set resolution does not work
by 陈新隆 31 Oct '22

31 Oct '22

Hi team, I've add a resolution sub-element to vga video device model, and the x attribute is 1920, y attribute is 1080. Dumped domain xml as follow : bash-4.4# virsh list > Authorization not available. Check if polkit service is running or see > debug message for more information. > Id Name State > ----------------------------------- > 1 proj1_vm-4uaz57bh running > bash-4.4# virsh dumpxml proj1_vm-4uaz57bh | grep -i -10 vga > Authorization not available. Check if polkit service is running or see > debug message for more information. > <alias name='input1'/> > </input> > <input type='keyboard' bus='ps2'> > <alias name='input2'/> > </input> > <graphics type='vnc' > socket='/var/run/kubevirt-private/dfe7d514-63f1-4e97-b642-f93109d5aa2f/virt-vnc'> > <listen type='socket' > socket='/var/run/kubevirt-private/dfe7d514-63f1-4e97-b642-f93109d5aa2f/virt-vnc'/> > </graphics> > <audio id='1' type='none'/> > <video> > <model type='vga' vram='65536' heads='1' primary='yes'> > <resolution x='1920' y='1080'/> > </model> > <alias name='video0'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x01' > function='0x0'/> > </video> > <memballoon model='virtio-non-transitional'> > <stats period='10'/> > <alias name='balloon0'/> > <address type='pci' domain='0x0000' bus='0x07' slot='0x00' > function='0x0'/> > </memballoon> It does work on my ubuntu guest, but it doesn't work on centos / windows guest. Is there any way to solve this problem ?

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Booting from USB device
by Simon Fairweather 28 Oct '22

28 Oct '22

I have a hooks file to hotplug a USB device at the prepare stage. Using OVMF version 2.6 this works fine, but using OVMF 2.7 the guest no longer boots from the USB device. Option 1) For it to work I have to set the boot order on the USB device and once the OVMF Shell appears I can reset it and it will find the USB device and boot. Option 2) Another setup which works if I remove all boot order settings from the guest and have a boot dev = 'fd' and this works every time.but I cannot add multiple entries. <os> <type arch='x86_64' machine='pc-q35-5.1'>hvm</type> <loader readonly='yes' type='pflash'>/usr/share/qemu/ovmf-x64/OVMF_CODE-pure-efi-tpm.fd</loader> <nvram>/etc/libvirt/qemu/nvram/b96bfc99-3612-0daa-9d8c-69e9d550d05a_VARS-pure-efi-tpm.fd</nvram> <boot dev='fd'/> <boot dev='hd'/> Any thoughts on how to get option 1) to working without having to do a reset.

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