I suddenly cant edit my vm anymore

I always get the following error: “could not find capabilities for arch=x86_64 domaintype=kvm”. Virtualization is enabled, the kernel modules are loaded and I can even start the vm. I am using arch_linux and libvirt 5.6.0-1 Is there a fix for this?

My config:

<domain type='kvm' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
    <name>win10</name>
    <uuid>898f32f8-56eb-4877-b670-f26c9a2a805f</uuid>
    <metadata>
        <libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
            <libosinfo:os id="http://microsoft.com/win/10"/>
        </libosinfo:libosinfo>
    </metadata>
    <memory unit='KiB'>10485760</memory>
    <currentMemory unit='KiB'>10485760</currentMemory>
    <vcpu placement='static'>8</vcpu>
    <iothreads>2</iothreads>
    <cputune>
        <vcpupin vcpu='0' cpuset='0'/>
        <vcpupin vcpu='1' cpuset='1'/>
        <vcpupin vcpu='2' cpuset='2'/>
        <vcpupin vcpu='3' cpuset='3'/>
        <vcpupin vcpu='4' cpuset='4'/>
        <vcpupin vcpu='5' cpuset='5'/>
        <vcpupin vcpu='6' cpuset='6'/>
        <vcpupin vcpu='7' cpuset='7'/>
        <emulatorsched scheduler='fifo' priority='1'/>
        <vcpusched vcpus='0' scheduler='fifo' priority='1'/>
        <vcpusched vcpus='1' scheduler='fifo' priority='1'/>
        <vcpusched vcpus='2' scheduler='fifo' priority='1'/>
        <vcpusched vcpus='3' scheduler='fifo' priority='1'/>
        <vcpusched vcpus='4' scheduler='fifo' priority='1'/>
        <vcpusched vcpus='5' scheduler='fifo' priority='1'/>
        <vcpusched vcpus='6' scheduler='fifo' priority='1'/>
        <vcpusched vcpus='7' scheduler='fifo' priority='1'/>
        <iothreadsched iothreads='1' scheduler='rr' priority='1'/>
        <iothreadsched iothreads='2' scheduler='rr' priority='1'/>
    </cputune>
    <os>
        <type arch='x86_64' machine='pc-q35-4.0'>hvm</type>
        <loader readonly='yes' type='pflash'>/usr/share/ovmf/x64/OVMF_CODE.fd</loader>
        <nvram>/var/lib/libvirt/qemu/nvram/win10_VARS.fd</nvram>
        <bootmenu enable='no'/>
    </os>
    <features>
        <acpi/>
        <apic/>
        <hyperv>
            <relaxed state='on'/>
            <vapic state='on'/>
            <spinlocks state='on' retries='8191'/>
            <vendor_id state='on' value='123456789ab'/>
        </hyperv>
        <kvm>
            <hidden state='on'/>
        </kvm>
        <vmport state='off'/>
        <ioapic driver='kvm'/>
    </features>
    <cpu mode='host-passthrough' check='none'>
        <topology sockets='1' cores='8' threads='1'/>
        <feature policy='require' name='invtsc'/>
        <feature policy='require' name='topoext'/>
    </cpu>
    <clock offset='utc'>
        <timer name='tsc' present='yes' mode='native'/>
        <timer name='hypervclock' present='yes'/>
    </clock>
    <on_poweroff>destroy</on_poweroff>
    <on_reboot>restart</on_reboot>
    <on_crash>destroy</on_crash>
    <pm>
        <suspend-to-mem enabled='no'/>
        <suspend-to-disk enabled='no'/>
    </pm>
    <devices>
        <emulator>/usr/bin/qemu-system-x86_64</emulator>
        <disk type='block' device='disk'>
            <driver name='qemu' type='raw' iothread='1'/>
            <source dev='/dev/sda1'/>
            <target dev='hda' bus='virtio'/>
            <boot order='1'/>
            <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0'/>
        </disk>
        <disk type='block' device='disk'>
            <driver name='qemu' type='raw' iothread='2'/>
            <source dev='/dev/sdb4'/>
             <target dev='hdb' bus='virtio'/>
            <address type='pci' domain='0x0000' bus='0x08' slot='0x00' function='0x0'/>
        </disk>
        <disk type='file' device='cdrom'>
            <driver name='qemu' type='raw'/>
            <target dev='sda' bus='sata'/>
            <readonly/>
            <address type='drive' controller='0' bus='0' target='0' unit='0'/>
        </disk>
        <controller type='sata' index='0'>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x1f' function='0x2'/>
        </controller>
        <controller type='pci' index='0' model='pcie-root'/>
        <controller type='pci' index='1' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='1' port='0x10'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0' multifunction='on'/>
        </controller>
        <controller type='pci' index='2' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='2' port='0x11'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x1'/>
        </controller>
        <controller type='pci' index='3' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='3' port='0x12'/>
             <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x2'/>
        </controller>
        <controller type='pci' index='4' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='4' port='0x13'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x3'/>
        </controller>
        <controller type='pci' index='5' model='pcie-root-port'>
            <model name='pcie-root-port'/>
             <target chassis='5' port='0x14'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x4'/>
        </controller>
        <controller type='pci' index='6' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='6' port='0x15'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x5'/>
        </controller>
        <controller type='pci' index='7' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='7' port='0x16'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x6'/>
        </controller>
        <controller type='pci' index='8' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='8' port='0x17'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x7'/>
        </controller>
        <controller type='pci' index='9' model='pcie-to-pci-bridge'>
            <model name='pcie-pci-bridge'/>
            <address type='pci' domain='0x0000' bus='0x06' slot='0x00' function='0x0'/>
        </controller>
        <controller type='pci' index='10' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='10' port='0x18'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
        </controller>
        <controller type='pci' index='11' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='11' port='0x8'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0' multifunction='on'/>
        </controller>
        <controller type='pci' index='12' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='12' port='0x9'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
        </controller>
        <controller type='pci' index='13' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='13' port='0xa'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
        </controller>
        <controller type='pci' index='14' model='pcie-root-port'>
            <model name='pcie-root-port'/>
            <target chassis='14' port='0xb'/>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x3'/>
        </controller>
        <controller type='virtio-serial' index='0'>
            <address type='pci' domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
        </controller>
        <controller type='usb' index='0' model='qemu-xhci' ports='15'>
            <address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/>
        </controller>
        <controller type='usb' index='1' model='ehci'>
            <address type='pci' domain='0x0000' bus='0x09' slot='0x01' function='0x0'/>
        </controller>
        <interface type='direct'>
            <mac address='52:54:00:f9:65:4f'/>
            <source dev='enp39s0' mode='bridge'/>
            <model type='e1000e'/>
            <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
        </interface>
        <interface type='bridge'>
            <mac address='52:54:00:c4:a5:f4'/>
            <source bridge='br0'/>
            <model type='e1000e'/>
            <link state='up'/>
            <address type='pci' domain='0x0000' bus='0x0a' slot='0x00' function='0x0'/>
        </interface>
        <input type='mouse' bus='ps2'/>
        <input type='keyboard' bus='ps2'/>
        <sound model='ich9'>
            <address type='pci' domain='0x0000' bus='0x00' slot='0x1b' function='0x0'/>
        </sound>
        <hostdev mode='subsystem' type='pci' managed='yes'>
            <source>
                <address domain='0x0000' bus='0x2d' slot='0x00' function='0x0'/>
            </source>
            <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/>
        </hostdev>
        <hostdev mode='subsystem' type='pci' managed='yes'>
            <source>
                <address domain='0x0000' bus='0x2d' slot='0x00' function='0x1'/>
            </source>
            <address type='pci' domain='0x0000' bus='0x0b' slot='0x00' function='0x0'/>
        </hostdev>
        <hostdev mode='subsystem' type='pci' managed='yes'>
            <source>
                <address domain='0x0000' bus='0x2d' slot='0x00' function='0x2'/>
            </source>
            <address type='pci' domain='0x0000' bus='0x0c' slot='0x00' function='0x0'/>
        </hostdev>
        <hostdev mode='subsystem' type='pci' managed='yes'>
            <source>
                <address domain='0x0000' bus='0x2d' slot='0x00' function='0x3'/>
            </source>
            <address type='pci' domain='0x0000' bus='0x0d' slot='0x00' function='0x0'/>
        </hostdev>
        <redirdev bus='usb' type='spicevmc'>
            <address type='usb' bus='0' port='2'/>
        </redirdev>
        <redirdev bus='usb' type='spicevmc'>
            <address type='usb' bus='0' port='3'/>
        </redirdev>
        <memballoon model='virtio' autodeflate='on'>
            <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x0'/>
        </memballoon>
        <shmem name='scream-ivshmem'>
            <model type='ivshmem-plain'/>
            <size unit='M'>2</size>
            <address type='pci' domain='0x0000' bus='0x09' slot='0x03' function='0x0'/>
        </shmem>
        <shmem name='looking-glass'>
            <model type='ivshmem-plain'/>
            <size unit='M'>32</size>
            <address type='pci' domain='0x0000' bus='0x09' slot='0x02' function='0x0'/>
        </shmem>
    </devices>
    <qemu:commandline>
        <qemu:env name='QEMU_AUDIO_DRV' value='pa'/>
        <qemu:env name='QEMU_PA_SAMPLES' value='8192'/>
        <qemu:env name='QEMU_AUDIO_TIMER_PERIOD' value='99'/>
        <qemu:env name='QEMU_PA_SERVER' value='/run/user/1000/pulse/native'/>
    </qemu:commandline>
</domain>

Hello,
I ran into this issue as well.
I am currently working around it by manually editing the virtual machines xml file and reloading it by doing a sudo service libvirtd restart.

I would love to know what causes this though. It appeared after some tinkering.
Best regards

I’m not experiencing this on my Arch system, but I would suspect your <type> parameter in the XML. It’s likely you need to adjust the machine identifier.

Just a shot in the dark.

I think, I had a error like that, last month.
It was because I edit my config and then it became invalid.
I was playing with my cpu topology, when it happen, windows can only support 2 socket.
If you have an old copy of your XML config roll it back.

In my case I rebuild a new VM, with the same resources.

1 Like

This seems to be the issue: https://www.reddit.com/r/archlinux/comments/derwi2/qemukvm_error_while_loading_shared_libraries/
I fixed it by creating a symbolic link from libvirglrenderer.so.0 to libvirglrenderer.so.1