- Users - libvirt List Archives

Linking virtual sound cards in two virtual machines?
by Lars Kellogg-Stedman 15 Apr '24

15 Apr '24

I would like to create a virtual audio cable between two libvirt guests such that sound output from guest A goes to sound input on guest B, and vice versa. I figure the solution to this is using something like the pulseaudio's "virtual sink", but I'm not entirely sure what the syntax would look like (fwiw, I'm on Fedora 39, which means libvirt 9.7.0, which means this has to be through libvirt's pulseaudio driver rather than the pipewire driver, since the latter isn't available in 9.7.0). I started by creating a virtual sink (and yes, I realize that's only half the process): pactl load-module module-null-sink sink_name=vaudio0 And adding the following snippet to the domain xml for guest "node1.virt": <audio id='1' type='pulseaudio'> <input name='vaudio0' streamName='node1-in' latency='100'/> <output name='vaudio0' streamName='node1-out' latency='100'/> </audio> But trying to start this guest results in: error: Failed to start domain 'node1.virt' error: internal error: process exited while connecting to monitor: audio: Could not init `pa' audio driver There doesn't appear to be any additional information in /var/log/libvirt/qemu/node1.virt.log. I'm wondering if someone has an example of what this might look like? Thanks, -- Lars Kellogg-Stedman <lars(a)redhat.com>

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'nconnect' nfs mount option support
by Abhisar Sinha 15 Apr '24

15 Apr '24

Hi, Is there a way to specify the 'nconnect' nfs mount opt value in the XML file used by 'virsh create-pool' command? If not, how hard would it be to implement this functionality? Please advise. Thanks, Abhisar

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TLS Configuration with libvirt and Perfect Forward Secrecy
by Tommy.J.Mairo 09 Apr '24

09 Apr '24

Dear libvirt Users, I'm seeking guidance on configuring TLS with libvirt to achieve perfect forward secrecy (PFS). While I followed the tutorial on setting up TLS with libvirt from the project wiki [1], I encountered an error when bringing up the legacy monolithic libvirt daemon. The error message, "Certificate /etc/pki/libvirt/servercert.pem usage does not permit key encipherment," appeared even though I declared the "encryption_key" field in the certtool template file when generating the server certificate. Moreover, when I inspected the generated certificate with certtool, I discovered that it only had a "Digital signature" entry under X509v3 key usage. The deficiency in "Key Encipherment" usage could result from the key type specifications when generating the private key with the command "certtool --generate-privkey --key-type=ed25519 --curve=Ed25519 --sec-param=ultra > /etc/pki/libvirt/private/serverkey.pem". I prefer using elliptic-curve cryptography, specifically curve25519, over RSA, which the tutorial employs. Although a digital signature-only certificate can still perform Diffie–Hellman exchanges with ECDSA, it cannot encrypt client-generated pre-master secrets. Nonetheless, a TLS session can still be established without pre-master secrets, avoiding session key leakage even if the decryption key is compromised in the future. This fulfills the PFS requirement, and I believe that a certificate without "Key Encipherment" usage contributes to the system's overall security. Based on my understanding, I am seeking any insights or suggestions on whether there is a way to suppress the "certificate usage does not permit key encipherment" error and allow the legacy monolithic libvirt daemon to proceed. Thanks, Tommy.J.Mairo [1] https://wiki.libvirt.org/TLSSetup.html

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all domains paused, maybe logging might be helpfull
by Lennart Fricke 21 Mar '24

21 Mar '24

Hello, I just hit the situation that all domains on a host where paused due to missing space. It took me some time to figure out that there was no space left for the images on the host. I learned that 'virsh domstate --reason $GUEST' and 'domblkerror $GUEST' could have helped me. But the logs are silent about the problem. Would it be possible to show these problems in logs or is there other documentation than the reference to find out how to troubleshoot those issues? Thank you Lennart

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Re: PCI Hotplug to a VM does not work in Alma
by Michal Prívozník 20 Mar '24

20 Mar '24

On 3/19/24 22:51, Chanda Mendon (cmendon) via Users wrote: > Hi > > We have a chassis with a peripheral PCI device installed. We have a > hypervisor running on the chassis where we have deployed a VM which can > use the PCI device once it is attached. > > When the PCI device is powered on or off we need to do a hotplug in/out > using virsh commands. Even though the virsh commands for hotplug is > executed successfully, the VM sees the PCI inside the VM for one or 2 > secs. What do you think is the issue? > [root ~]# uname -a > > Linux 4.18.0-372.9.1.el8.x86_64 #1 SMP Fri Mar 15 05:32:38 UTC 2024 > x86_64 x86_64 x86_64 GNU/Linux > > [root ~]# virsh --version > > 8.0.0 > > [root ~]# rpm -qa | grep libvirt > > libvirt-daemon-driver-nwfilter-8.0.0-5.el8.x86_64 > > python3-libvirt-7.8.0-1.el8.x86_64 > > libvirt-daemon-driver-storage-logical-8.0.0-5.el8.x86_64 > > libvirt-libs-8.0.0-5.el8.x86_64 > > libvirt-daemon-config-nwfilter-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-gluster-8.0.0-5.el8.x86_64 > > libvirt-8.0.0-5.el8.x86_64 > > libvirt-daemon-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-nodedev-8.0.0-5.el8.x86_64 > > libvirt-daemon-config-network-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-iscsi-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-rbd-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-network-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-secret-8.0.0-5.el8.x86_64 > > python2-libvirt-python-5.10.0-1.el8.x86_64 > > libvirt-daemon-driver-qemu-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-core-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-iscsi-direct-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-scsi-8.0.0-5.el8.x86_64 > > libvirt-client-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-disk-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-interface-8.0.0-5.el8.x86_64 > > libvirt-daemon-driver-storage-mpath-8.0.0-5.el8.x86_64 > > libvirt-daemon-kvm-8.0.0-5.el8.x86_64 > > [root ~]# rpm -qa | grep qemu > > qemu-kvm-ui-opengl-6.2.0-11.el8.x86_64 > > qemu-kvm-6.2.0-11.el8.x86_64 > > qemu-img-6.2.0-11.el8.x86_64 > > qemu-kvm-block-iscsi-6.2.0-11.el8.x86_64 > > ipxe-roms-qemu-20200823-7.git4bd064de.el8.noarch > > qemu-kvm-block-gluster-6.2.0-11.el8.x86_64 > > qemu-kvm-block-rbd-6.2.0-11.el8.x86_64 > > qemu-kvm-block-curl-6.2.0-11.el8.x86_64 > > qemu-kvm-core-6.2.0-11.el8.x86_64 > > qemu-kvm-hw-usbredir-6.2.0-11.el8.x86_64 > > libvirt-daemon-driver-qemu-8.0.0-5.el8.x86_64 > > qemu-kvm-ui-spice-6.2.0-11.el8.x86_64 > > qemu-kvm-docs-6.2.0-11.el8.x86_64 > > qemu-kvm-block-ssh-6.2.0-11.el8.x86_64 > > qemu-kvm-common-6.2.0-11.el8.x86_64 > > > > [root ~]# *virsh nodedev-dettach** **pci_0000_04_00_0* > > [12013.987821] pci_probe_reset_slot: call pci_slot_reset with probe=1 > > [12014.063669] pci_slot_reset (printk info): reset hotplug slot. > > [12014.134164] pci_reset_hotplug_slot(printk INFO): calling reset_slot > (probe = 1) > > [Mar19 21:09] pci_probe_reset_slot: call pci_slot_reset with probe=1 > > [ +0.075848] pci_slot_reset (printk info): reset hotplug slot. > > [ +0.070495] pci_reset_hotplug_slot(printk INFO): calling reset_slot > (probe = 1) > > *Device pci_0000_04_00_0 detached*** > > > > [root ~]# *virsh attach-device ROUTER8 /opt/us/bin/mrvl.xml* > > [12024.217540] pci_probe_reset_slot: call pci_slot_reset with probe=1 > > [ +10.083376] pci_probe_reset_slot: call pci_slot_reset with > probe=1[12024.293548] pci_slot_reset (printk info): reset hotplug slot. The fact that the device resets so often might suggest a problem with the device itself. But since QEMU is seeing the device (even if only for a brief period), I think libvirt's out of the picture. Perhaps QEMU folks might have a better answer. Michal

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PCI Hotplug to a VM does not work in Alma
by Chanda Mendon (cmendon) 19 Mar '24

19 Mar '24

Hi We have a chassis with a peripheral PCI device installed. We have a hypervisor running on the chassis where we have deployed a VM which can use the PCI device once it is attached. When the PCI device is powered on or off we need to do a hotplug in/out using virsh commands. Even though the virsh commands for hotplug is executed successfully, the VM sees the PCI inside the VM for one or 2 secs. What do you think is the issue? [root ~]# uname -a Linux 4.18.0-372.9.1.el8.x86_64 #1 SMP Fri Mar 15 05:32:38 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux [root ~]# virsh --version 8.0.0 [root ~]# rpm -qa | grep libvirt libvirt-daemon-driver-nwfilter-8.0.0-5.el8.x86_64 python3-libvirt-7.8.0-1.el8.x86_64 libvirt-daemon-driver-storage-logical-8.0.0-5.el8.x86_64 libvirt-libs-8.0.0-5.el8.x86_64 libvirt-daemon-config-nwfilter-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-gluster-8.0.0-5.el8.x86_64 libvirt-8.0.0-5.el8.x86_64 libvirt-daemon-8.0.0-5.el8.x86_64 libvirt-daemon-driver-nodedev-8.0.0-5.el8.x86_64 libvirt-daemon-config-network-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-iscsi-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-rbd-8.0.0-5.el8.x86_64 libvirt-daemon-driver-network-8.0.0-5.el8.x86_64 libvirt-daemon-driver-secret-8.0.0-5.el8.x86_64 python2-libvirt-python-5.10.0-1.el8.x86_64 libvirt-daemon-driver-qemu-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-core-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-iscsi-direct-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-scsi-8.0.0-5.el8.x86_64 libvirt-client-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-disk-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-8.0.0-5.el8.x86_64 libvirt-daemon-driver-interface-8.0.0-5.el8.x86_64 libvirt-daemon-driver-storage-mpath-8.0.0-5.el8.x86_64 libvirt-daemon-kvm-8.0.0-5.el8.x86_64 [root ~]# rpm -qa | grep qemu qemu-kvm-ui-opengl-6.2.0-11.el8.x86_64 qemu-kvm-6.2.0-11.el8.x86_64 qemu-img-6.2.0-11.el8.x86_64 qemu-kvm-block-iscsi-6.2.0-11.el8.x86_64 ipxe-roms-qemu-20200823-7.git4bd064de.el8.noarch qemu-kvm-block-gluster-6.2.0-11.el8.x86_64 qemu-kvm-block-rbd-6.2.0-11.el8.x86_64 qemu-kvm-block-curl-6.2.0-11.el8.x86_64 qemu-kvm-core-6.2.0-11.el8.x86_64 qemu-kvm-hw-usbredir-6.2.0-11.el8.x86_64 libvirt-daemon-driver-qemu-8.0.0-5.el8.x86_64 qemu-kvm-ui-spice-6.2.0-11.el8.x86_64 qemu-kvm-docs-6.2.0-11.el8.x86_64 qemu-kvm-block-ssh-6.2.0-11.el8.x86_64 qemu-kvm-common-6.2.0-11.el8.x86_64 [root ~]# virsh nodedev-dettach pci_0000_04_00_0 [12013.987821] pci_probe_reset_slot: call pci_slot_reset with probe=1 [12014.063669] pci_slot_reset (printk info): reset hotplug slot. [12014.134164] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [Mar19 21:09] pci_probe_reset_slot: call pci_slot_reset with probe=1 [ +0.075848] pci_slot_reset (printk info): reset hotplug slot. [ +0.070495] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) Device pci_0000_04_00_0 detached [root ~]# virsh attach-device ROUTER8 /opt/us/bin/mrvl.xml [12024.217540] pci_probe_reset_slot: call pci_slot_reset with probe=1 [ +10.083376] pci_probe_reset_slot: call pci_slot_reset with probe=1[12024.293548] pci_slot_reset (printk info): reset hotplug slot. [12024.434828] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [ +0.076008] pci_slot_reset (printk info): reset hotplug slot. [ +0.141280] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1)4.526807] pci_probe_reset_slot: call pci_slot_reset with probe=1 [12024.749367] pci_slot_reset (printk info): reset hotplug slot. [12024.821327] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [ +0.091979] pci_probe_reset_slot: call pci_slot_reset with probe=1[12024.911065] pci_probe_reset_slot: call pci_slot_reset with probe=1 [ +0.222560] pci_slot_reset (printk info): reset hotplug slot. [ +0.071960] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) 5.057584] pci_slot_reset (printk info): reset hotplug slot. [ +0.089738] pci_probe_reset_slot: call pci_slot_reset with probe=1 [12025.278585] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [ +0.146519] pci_slot_reset (printk info): reset hotplug slot. [ +0.221001] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) 5.441574] pci_probe_reset_slot: call pci_slot_reset with probe=1 [ +0.162989] pci_probe_reset_slot: call pci_slot_reset with probe=1[12025.665968] pci_slot_reset (printk info): reset hotplug slot. [12025.806751] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [12025.898060] __pci_reset_slot (printk info): Reset slot (not hotplug), probe = 1. [ +0.224394] pci_slot_reset (printk info): reset hotplug slot. [ +0.140783] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1)5.988477] pci_slot_reset (printk info): reset hotplug slot. [ +0.091309] __pci_reset_slot (printk info): Reset slot (not hotplug), probe = 1. 12026.205654] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [12026.383424] __pci_reset_slot (printk info): pci_slot_trylock is non-zero, so reset hotplug slot. [ +0.090417] pci_slot_reset (printk info): reset hotplug slot. [ +0.217177] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1)6.490406] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 0) [ +0.177770] __pci_reset_slot (printk info): pci_slot_trylock is non-zero, so reset hotplug slot. 2026.726579] pciehp_reset_slot: SLOTCTRL 58 write cmd 0 [ +0.106982] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 0) [ +0.236167] pcieport 0000:00:0e.0: pciehp: pciehp_reset_slot: SLOTCTRL 58 write cmd 0 [ +0.000006] pciehp_reset_slot: SLOTCTRL 58 write cmd 0 [12027.744480] pending interrupts 0x0108 from Slot Status [ +1.017890] pcieport 0000:00:0e.0: pciehp: pending interrupts 0x0108 from Slot Status [ +0.000011] pending interrupts 0x0108 from Slot Status [12027.936469] pciehp_reset_slot: SLOTCTRL 58 write cmd 1008 [ +0.191983] pcieport 0000:00:0e.0: pciehp: pciehp_reset_slot: SLOTCTRL 58 write cmd 100812028.027182] pcieport 0000:00:0e.0: pciehp: Slot(4): Link Down [12028.190357] Slot(4): Link Down [ +0.000006] pciehp_reset_slot: SLOTCTRL 58 write cmd 1008[12028.230605] pcieport 0000:00:0e.0: pciehp: Slot(4): Card not present [12028.369819] Slot(4): Card not present Device attached successfully [12028.415302] pciehp_unconfigure_device: domain:bus:dev = 0000:04:00 [ +0.090713] pcieport 0000:00:0e.0: pciehp: Slot(4): Link Down[12028.524356] vfio-pci 0000:04:00.0: Relaying device request to user (#0) [ +0.163175] Slot(4): Link Down [ +0.040248] pcieport 0000:00:0e.0: pciehp: Slot(4): Card not present [ +0.139214] Slot(4): Card not present [ +0.045479] pcieport 0000:00:0e.0: pciehp: pciehp_unconfigure_device: domain:bus:dev = 0000:04:00 [ +0.000004] pciehp_unconfigure_device: domain:bus:dev = 0000:04:00 [ +0.109054] vfio-pci 0000:04:00.0: Relaying device request to user (#0) 9119] pci_probe_reset_slot: call pci_slot_reset with probe=1 [root@nfvis ~]# [12029.151422] pci_slot_reset (printk info): reset hotplug slot. [12029.237806] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [ +0.334763] pci_probe_reset_slot: call pci_slot_reset with probe=1[12029.327572] pci_probe_reset_slot: call pci_slot_reset with probe=1 [ +0.292303] pci_slot_reset (printk info): reset hotplug slot. [ +0.086384] pci_r12029.474447] pci_slot_reset (printk info): reset hotplug slot. eset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [12029.632533] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [ +0.089766] pci_probe_reset_slot: call pci_slot_reset with probe=1[12029.788423] __pci_reset_slot (printk info): Reset slot (not hotplug), probe = 1. [ +0.146875] pci_slot_reset (printk info): reset hotplug slot. [12029.950782] pci_slot_reset (printk info): reset hotplug slot. [ +0.158086] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [ +0.155890] __pci_reset_slot (printk info): Reset slot (not hotplug), probe = 1. .089787] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1) [12030.346708] __pci_reset_slot (printk info): pci_slot_trylock = 0, so don't reset hotplug slot. [ +0.162359] pci_slot_reset (printk info): reset hotplug slot.[12030.451555] vfio-pci 0000:04:00.0: can't change power state from D0 to D3hot (config space inaccessible) [ +0.139005] pci_reset_hotplug_slot(printk INFO): calling reset_slot (probe = 1)12030.632974] pci 0000:04:00.0: Removing from iommu group 58 [ +0.256921] __pci_reset_slot (printk info): pci_slot_trylock = 0, so don't reset hotplug slot. [ +0.104847] vfio-pci 0000:04:00.0: can't change power state from D0 to D3hot (config space inaccessible) 5279] pciehp_check_link_active: lnk_status = 7011 [ +0.181419] pci 0000:04:00.0: Removing from iommu group 58 [12031.056747] pcieport 0000:00:0e.0: pciehp: Slot(4): Card present [12031.194871] Slot(4): Card present [ +0.152301] pcieport 0000:00:0e.0: pciehp: pciehp_check_link_active: lnk_status = 701112031.236173] pcieport 0000:00:0e.0: pciehp: Slot(4): Link Up [12031.395181] Slot(4): Link Up [ +0.000004] pciehp_check_link_active: lnk_status = 7011 [ +0.271468] pcieport 0000:00:0e.0: pciehp: Slot(4): Card present [ +0.138124] Slot(4): Card present [ +0.041302] pcieport 0000:00:0e.0: pciehp: Slot(4): Link Up [ +0.159008] Slot(4): Link Up 31.560448] read_dev_vendor_id: read config_dword worked. bus = 4, dev_vendor id = 0xE61E11AB [12031.803909] read_dev_vendor_id: device found, return true. bus = 4, dev_vendor id = 0xE61E11AB [12031.909784] pciehp_check_link_status: lnk_status = 7011 [ +0.165267] read_dev_vendor_id: read config_dword worked. bus = 4, dev_vendor id = 0xE61E11AB2031.974018] read_dev_vendor_id: read config_dword worked. bus = 4, dev_vendor id = 0xE61E11AB [12032.176762] read_dev_vendor_id: device found, return true. bus = 4, dev_vendor id = 0xE61E11AB [ +0.243461] read_dev_vendor_id: device found, return true. bus = 4, dev_vendor id = 0xE61E11AB [ +0.105871] pcieport 0000:00:0e.0: pciehp: pciehp_check_link_status: lnk_status = 7011282681] pci 0000:04:00.0: [11ab:e61e] type 00 class 0x020000 [ +0.000004] pciehp_check_link_status: lnk_status = 7011 [12032.545840] pci 0000:04:00.0: reg 0x10: [mem 0x7b44000000-0x7b440fffff 64bit pref] [12032.701716] pci 0000:04:00.0: reg 0x18: [mem 0x7b40000000-0x7b43ffffff 64bit pref] [ +0.064234] read_dev_vendor_id: read config_dword worked. bus = 4, dev_vendor id = 0xE61E11AB2032.794062] pci 0000:04:00.0: reg 0x20: [mem 0x7b30000000-0x7b3fffffff 64bit pref] [12032.984416] pci 0000:04:00.0: supports D1 D2 [ +0.202744] read_dev_vendor_id: device found, return true. bus = 4, dev_vendor id = 0xE61E11AB2033.039350] pci 0000:04:00.0: Adding to iommu group 58 [12033.201376] pci 0000:04:00.0: BAR 4: assigned [mem 0x7b30000000-0x7b3fffffff 64bit pref] [12033.299989] pci 0000:04:00.0: BAR 2: assigned [mem 0x7b40000000-0x7b43ffffff 64bit pref] [ +0.105919] pci 0000:04:00.0: [11ab:e61e] type 00 class 0x020000[12033.400664] pci 0000:04:00.0: BAR 0: assigned [mem 0x7b44000000-0x7b440fffff 64bit pref] [ +0.263159] pci 0000:04:00.0: reg 0x10: [mem 0x7b44000000-0x7b440fffff 64bit pref]12033.568019] pcieport 0000:00:0e.0: PCI bridge to [bus 04-06] [12033.725967] pcieport 0000:00:0e.0: bridge window [io 0xd000-0xdfff] [ +0.155876] pci 0000:04:00.0: reg 0x18: [mem 0x7b40000000-0x7b43ffffff 64bit pref]12033.805813] pcieport 0000:00:0e.0: bridge window [mem 0xdc000000-0xdcffffff] [12033.982533] pcieport 0000:00:0e.0: bridge window [mem 0x7b30000000-0x7b6fffffff 64bit pref] [ +0.092346] pci 0000:04:00.0: reg 0x20: [mem 0x7b30000000-0x7b3fffffff 64bit pref]12034.086495] pci-stub 0000:04:00.0: claimed by stub [ +0.190354] pci 0000:04:00.0: supports D1 D2 [ +0.054934] pci 0000:04:00.0: Adding to iommu group 58 [ +0.162026] pci 0000:04:00.0: BAR 4: assigned [mem 0x7b30000000-0x7b3fffffff 64bit pref] [ +0.098613] pci 0000:04:00.0: BAR 2: assigned [mem 0x7b40000000-0x7b43ffffff 64bit pref] [ +0.100675] pci 0000:04:00.0: BAR 0: assigned [mem 0x7b44000000-0x7b440fffff 64bit pref] [ +0.167355] pcieport 0000:00:0e.0: PCI bridge to [bus 04-06] [ +0.157948] pcieport 0000:00:0e.0: bridge window [io 0xd000-0xdfff] [ +0.079846] pcieport 0000:00:0e.0: bridge window [mem 0xdc000000-0xdcffffff] [ +0.176720] pcieport 0000:00:0e.0: bridge window [mem 0x7b30000000-0x7b6fffffff 64bit pref] [ +0.103962] pci-stub 0000:04:00.0: claimed by stub Thank you for replying in advance, -Chanda

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Automate VM migration
by aheath1992＠gmail.com 19 Mar '24

19 Mar '24

Are their any tools that can automatically migrate VMs from one host to another, like in VMware, proxmox, and oVirt?

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Info regarding AMX support and libvirt implications
by Gianluca Cecchi 08 Mar '24

08 Mar '24

Hello, I'm trying to use AMX in my virtual machines. More info on AMX: https://www.intel.com/content/www/us/en/products/docs/accelerator-engines/a… My system in test is currently SLES 15 SP5. I'm also verifying in parallel with Suse (especially regarding the backported features in their 5.14 based kernel), but in the meantime I would like to understand implication, if any, of libvirt in the certification loop I have to analyse. From what I see we have in upstream: . support in the KVM kernel module since 5.17 . support of cpu model SapphireRapids, the first offering AMX as an ISA extension, in QEMU since 7.0 Is there any dependance to check on libvirt too? When I run virsh cpu-models x86_64 Is libvirt sw stack querying qemu directly? Or the kvm kernel module? Or any internal "database" file? From man page it is not clear to me what "known" means: " cpu-models Syntax: cpu-models arch Print the list of CPU models known by libvirt for the specified architecture. Whether a specific hypervisor is able to create a domain which uses any of the printed CPU models is a separate question which can be answered by looking at the domain capabilities XML returned by domcapabilities command. Moreover, for some architectures libvirt does not know any CPU models and the usable CPU models are only limited by the hypervisor. This command will print that all CPU models are accepted for these architectures and the actual list of supported CPU models can be checked in the domain capabilities XML. " In SLES 15 SP5 with: qemu-7.1.0-150500.49.9.2.x86_64 kernel-default-5.14.21-150500.55.49.1.x86_64 libvirtd-*-9.0.0-150500.6.11.1.x86_64 I get # virsh cpu-models x86_64 ... Cascadelake-Server Cascadelake-Server-noTSX Icelake-Client Icelake-Client-noTSX Icelake-Server Icelake-Server-noTSX Cooperlake Snowridge athlon phenom Opteron_G1 Opteron_G2 ... # virsh domcapabilities | grep -i sapphirerapid # In fedora39 with qemu-8.1.3-4.fc39.x86_64 kernel-6.7.5-200.fc39.x86_64 libvirt-*-9.7.0-2.fc39.x86_64 I get # virsh cpu-models x86_64 ... Cascadelake-Server Cascadelake-Server-noTSX Icelake-Client Icelake-Client-noTSX Icelake-Server Icelake-Server-noTSX Cooperlake Snowridge SapphireRapids athlon phenom Opteron_G1 Opteron_G2 ... # virsh domcapabilities | grep -i sapphirerapids <model usable='no' vendor='Intel'>SapphireRapids</model> # because I'm running on a client system without AMX support Thanks in advance, Gianluca

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Raspberry Pi 5 suggestion
by K otgc 07 Mar '24

07 Mar '24

Hello, the libvirt documentation <https://libvirt.org/apps.html> has nothing on installing libvirt to Raspberry Pi 5, so the documentation says to email <https://libvirt.org/contact.html> any suggestions. Cheers, Ken.

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virsh undefine --nvram
by Chuck Lever 06 Mar '24

06 Mar '24

Hello - The virsh(1) man page says: > --nvram and --keep-nvram specify accordingly to delete or keep nvram (/domain/os/nvram/) file. However on my Fedora 39 system with libvirt 9.7.0, using "virsh undefine --nvram" option appears to leave the NVRAM backing file: cel@boudin:~$ ls ~/.config/libvirt/qemu/nvram guestfs-02a4oblo9vg7888d_VARS.qcow2 guestfs-7hmiolqcqwz5b0qs_VARS.qcow2 guestfs-el7lqymnwgzpnr38_VARS.qcow2 guestfs-jp0tfneh205xjrh8_VARS.qcow2 guestfs-mhqbp4gwmqsuu9w3_VARS.qcow2 guestfs-sat7x2kgpg9opjds_VARS.qcow2 guestfs-vhhi476rsq7vh83z_VARS.qcow2 guestfs-177mrq9xrb5589wl_VARS.qcow2 guestfs-88p8heyq1j0sy8bk_VARS.qcow2 guestfs-gxul3j9e1h3po19o_VARS.qcow2 guestfs-k0jf8msw4kh3yuff_VARS.qcow2 guestfs-oakcwpbozezvids8_VARS.qcow2 guestfs-sinmkv97r4k4dzcd_VARS.qcow2 guestfs-vj5cu9hgwcv0f18u_VARS.qcow2 guestfs-6jnim67ceme3h369_VARS.qcow2 guestfs-89g707uzdttxb9hv_VARS.qcow2 guestfs-h6vzt9zqxhoxx0hj_VARS.qcow2 guestfs-k4hw4gkcq8u0eebj_VARS.qcow2 guestfs-pljksgeblxgyf0pw_VARS.qcow2 guestfs-t8bnntykpzm3qvh2_VARS.qcow2 guestfs-ynbxqtj01sn4ovwy_VARS.qcow2 guestfs-6sqhenv6ditrq410_VARS.qcow2 guestfs-at8lndx32y69bjmg_VARS.qcow2 guestfs-ht0uycdn3vwdozad_VARS.qcow2 guestfs-lfy19ftph83jo4v0_VARS.qcow2 guestfs-qj0c2u9w2k4ors6h_VARS.qcow2 guestfs-tmq0h36spng4vtwk_VARS.qcow2 guestfs-7erqks7ks5c8rj38_VARS.qcow2 guestfs-ba2kzqxb1pna12l5_VARS.qcow2 guestfs-is7avsxjtnig5kgb_VARS.qcow2 guestfs-m3nrhs3x58rlget9_VARS.qcow2 guestfs-rilsled4ff9wvk6v_VARS.qcow2 guestfs-veebmlno2okc7c8h_VARS.qcow2 cel@boudin:~$ Or perhaps I do not understand what these files are. -- Chuck Lever

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