Launching qemu/kvm Windows guest interupt downloads in host browser

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Recently, I just found a weird behaviour related to qemu/kvm. Whenever I launch/shutdown my Windows guest through virt-manager, my downloads in my host browser (Microsoft Edge) are interrupted and fail. I couldn’t find much information about this weird behaviour anywhere, so would just like to check if there is anyone having the same issue?

Below is the configuration of my virtual machine:

<domain type='kvm'>
  <name>Windows_Home</name>
  <uuid>cfb4dfb0-aacb-45be-9e2c-f73d25c7155c</uuid>
  <metadata>
    <libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
      <libosinfo:os id="http://microsoft.com/win/11"/>
    </libosinfo:libosinfo>
  </metadata>
  <memory unit='KiB'>4194304</memory>
  <currentMemory unit='KiB'>4194304</currentMemory>
  <memoryBacking>
    <source type='memfd'/>
    <access mode='shared'/>
  </memoryBacking>
  <vcpu placement='static'>4</vcpu>
  <os firmware='efi'>
    <type arch='x86_64' machine='pc-q35-6.1'>hvm</type>
    <firmware>
      <feature enabled='no' name='enrolled-keys'/>
      <feature enabled='yes' name='secure-boot'/>
    </firmware>
    <loader readonly='yes' secure='yes' type='pflash' format='raw'>/usr/share/edk2/x64/OVMF_CODE.secboot.4m.fd</loader>
    <nvram template='/usr/share/edk2/x64/OVMF_VARS.4m.fd' templateFormat='raw' format='raw'>/var/lib/libvirt/qemu/nvram/Windows_Home_VARS.fd</nvram>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <hyperv mode='custom'>
      <relaxed state='on'/>
      <vapic state='on'/>
      <spinlocks state='on' retries='8191'/>
    </hyperv>
    <vmport state='off'/>
    <smm state='on'/>
  </features>
  <cpu mode='host-model' check='partial'>
    <topology sockets='1' dies='1' clusters='1' cores='4' threads='1'/>
  </cpu>
  <clock offset='localtime'>
    <timer name='rtc' tickpolicy='catchup'/>
    <timer name='pit' tickpolicy='delay'/>
    <timer name='hpet' present='no'/>
    <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='file' device='disk'>
      <driver name='qemu' type='qcow2' discard='unmap'/>
      <source file='/data/VM/Windows_Home.qcow2'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x05' slot='0x00' function='0x0'/>
    </disk>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <source file='/var/lib/libvirt/images/virtio-win-stable.iso'/>
      <target dev='sda' bus='sata'/>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
    <controller type='usb' index='0' model='qemu-xhci' ports='15'>
      <address type='pci' domain='0x0000' bus='0x03' slot='0x00' function='0x0'/>
    </controller>
    <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-to-pci-bridge'>
      <model name='pcie-pci-bridge'/>
      <address type='pci' domain='0x0000' bus='0x01' slot='0x00' function='0x0'/>
    </controller>
    <controller type='pci' index='9' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='9' port='0x17'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x7'/>
    </controller>
    <controller type='virtio-serial' index='0'>
      <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0'/>
    </controller>
    <interface type='network'>
      <mac address='52:54:00:db:3b:44'/>
      <source network='default'/>
      <model type='virtio'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x00' function='0x0'/>
    </interface>
    <serial type='pty'>
      <target type='isa-serial' port='0'>
        <model name='isa-serial'/>
      </target>
    </serial>
    <console type='pty'>
      <target type='serial' port='0'/>
    </console>
    <channel type='spicevmc'>
      <target type='virtio' name='com.redhat.spice.0'/>
      <address type='virtio-serial' controller='0' bus='0' port='1'/>
    </channel>
    <channel type='spiceport'>
      <source channel='org.spice-space.webdav.0'/>
      <target type='virtio' name='org.spice-space.webdav.0'/>
      <address type='virtio-serial' controller='0' bus='0' port='2'/>
    </channel>
    <input type='tablet' bus='usb'>
      <address type='usb' bus='0' port='1'/>
    </input>
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <tpm model='tpm-tis'>
      <backend type='emulator' version='2.0'/>
    </tpm>
    <graphics type='spice' autoport='yes'>
      <listen type='address'/>
      <image compression='off'/>
    </graphics>
    <sound model='ich9'>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x1b' function='0x0'/>
    </sound>
    <audio id='1' type='spice'/>
    <video>
      <model type='qxl' ram='65536' vram='65536' vgamem='65536' heads='1' primary='yes'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/>
    </video>
    <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>
    <watchdog model='i6300esb' action='reset'>
      <address type='pci' domain='0x0000' bus='0x08' slot='0x01' function='0x0'/>
    </watchdog>
    <watchdog model='itco' action='reset'/>
    <memballoon model='virtio'>
      <address type='pci' domain='0x0000' bus='0x06' slot='0x00' function='0x0'/>
    </memballoon>
    <rng model='virtio'>
      <backend model='random'>/dev/urandom</backend>
      <address type='pci' domain='0x0000' bus='0x07' slot='0x00' function='0x0'/>
    </rng>
  </devices>
</domain>

And here’s my system information:

System:
  Kernel: 6.12.48-1-MANJARO arch: x86_64 bits: 64 compiler: gcc v: 15.2.1
    clocksource: tsc avail: hpet,acpi_pm parameters: initrd=\amd-ucode.img
    initrd=\intel-ucode.img initrd=\initramfs-6.12-x86_64.img
    zfs=zroot/manjaro/root rw resume=UUID=953b078f-9c44-4da8-9201-8b8133b66e9f
    amd_pstate=guided splash quiet
  Desktop: KDE Plasma v: 6.3.6 tk: Qt v: N/A info: frameworks v: 6.18.0
    wm: kwin_wayland vt: 2 dm: SDDM Distro: Manjaro base: Arch Linux
Machine:
  Type: Desktop System: ASUS product: N/A v: N/A serial: <superuser required>
  Mobo: ASUSTeK model: ROG CROSSHAIR VIII DARK HERO v: Rev X.0x
    serial: <superuser required> part-nu: SKU uuid: <superuser required>
    UEFI: American Megatrends v: 4501 date: 04/19/2023
Battery:
  Device-1: hidpp_battery_0 model: Logitech Wireless Keyboard serial: <filter>
    charge: 55% (should be ignored) rechargeable: yes status: discharging
CPU:
  Info: model: AMD Ryzen 7 5800X bits: 64 type: MT MCP arch: Zen 3+ gen: 3
    level: v3 note: check built: 2022 process: TSMC n6 (7nm) family: 0x19 (25)
    model-id: 0x21 (33) stepping: 0 microcode: 0xA20102E
  Topology: cpus: 1x dies: 1 clusters: 1 cores: 8 threads: 16 tpc: 2
    smt: enabled cache: L1: 512 KiB desc: d-8x32 KiB; i-8x32 KiB L2: 4 MiB
    desc: 8x512 KiB L3: 32 MiB desc: 1x32 MiB
  Speed (MHz): avg: 744 min/max: 550/4851 boost: enabled scaling:
    driver: amd-pstate governor: schedutil cores: 1: 744 2: 744 3: 744 4: 744
    5: 744 6: 744 7: 744 8: 744 9: 744 10: 744 11: 744 12: 744 13: 744 14: 744
    15: 744 16: 744 bogomips: 121660
  Flags-basic: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3
    svm
  Vulnerabilities:
  Type: gather_data_sampling status: Not affected
  Type: indirect_target_selection status: Not affected
  Type: itlb_multihit status: Not affected
  Type: l1tf status: Not affected
  Type: mds status: Not affected
  Type: meltdown status: Not affected
  Type: mmio_stale_data status: Not affected
  Type: reg_file_data_sampling status: Not affected
  Type: retbleed status: Not affected
  Type: spec_rstack_overflow mitigation: Safe RET
  Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via
    prctl
  Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer
    sanitization
  Type: spectre_v2 mitigation: Retpolines; IBPB: conditional; IBRS_FW;
    STIBP: always-on; RSB filling; PBRSB-eIBRS: Not affected; BHI: Not
    affected
  Type: srbds status: Not affected
  Type: tsa mitigation: Clear CPU buffers
  Type: tsx_async_abort status: Not affected
  Type: vmscape mitigation: IBPB before exit to userspace
Graphics:
  Device-1: NVIDIA AD102 [GeForce RTX 4090] vendor: Micro-Star MSI
    driver: nvidia v: 580.82.09 alternate: nouveau,nvidia_drm
    non-free: 550-580.xx+ status: current (as of 2025-08) arch: Lovelace
    code: AD1xx process: TSMC n4 (5nm) built: 2022+ pcie: gen: 4 speed: 16 GT/s
    lanes: 16 ports: active: DP-1 empty: DP-2,DP-3,HDMI-A-1 bus-ID: 0b:00.0
    chip-ID: 10de:2684 class-ID: 0300
  Device-2: Logitech Webcam C930e driver: snd-usb-audio,uvcvideo type: USB
    rev: 2.0 speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 3-2.3:3
    chip-ID: 046d:0843 class-ID: 0102 serial: <filter>
  Display: wayland server: X.org v: 1.21.1.18 with: Xwayland v: 24.1.8
    compositor: kwin_wayland driver: X: loaded: nvidia
    gpu: nv_platform,nvidia,nvidia-nvswitch display-ID: 0
  Monitor-1: DP-1 model: Samsung U28E590 serial: <filter> built: 2018 res:
    mode: 3840x2160 hz: 60 scale: 150% (1.5) to: 2560x1440 dpi: 161 gamma: 1.2
    size: 607x345mm (23.9x13.58") diag: 698mm (27.5") ratio: 16:9 modes:
    max: 3840x2160 min: 640x480
  API: EGL v: 1.5 hw: drv: nvidia platforms: device: 0 drv: nvidia device: 2
    drv: swrast gbm: drv: nvidia surfaceless: drv: nvidia wayland: drv: nvidia
    x11: drv: nvidia inactive: device-1
  API: OpenGL v: 4.6.0 compat-v: 4.5 vendor: nvidia mesa v: 580.82.09
    glx-v: 1.4 direct-render: yes renderer: NVIDIA GeForce RTX 4090/PCIe/SSE2
    memory: 23.43 GiB display-ID: :0.0
  API: Vulkan v: 1.4.321 layers: 6 device: 0 type: discrete-gpu
    name: NVIDIA GeForce RTX 4090 driver: nvidia v: 580.82.09
    device-ID: 10de:2684 surfaces: N/A
  Info: Tools: api: clinfo, eglinfo, glxinfo, vulkaninfo
    de: kscreen-console,kscreen-doctor gpu: nvidia-settings,nvidia-smi
    wl: wayland-info x11: xdpyinfo, xprop, xrandr
Audio:
  Device-1: NVIDIA AD102 High Definition Audio vendor: Micro-Star MSI
    driver: snd_hda_intel v: kernel pcie: gen: 4 speed: 16 GT/s lanes: 16
    bus-ID: 0b:00.1 chip-ID: 10de:22ba class-ID: 0403
  Device-2: Advanced Micro Devices [AMD] Starship/Matisse HD Audio
    vendor: ASUSTeK driver: snd_hda_intel v: kernel pcie: gen: 4 speed: 16 GT/s
    lanes: 16 bus-ID: 0d:00.4 chip-ID: 1022:1487 class-ID: 0403
  Device-3: Logitech Webcam C930e driver: snd-usb-audio,uvcvideo type: USB
    rev: 2.0 speed: 480 Mb/s lanes: 1 mode: 2.0 bus-ID: 3-2.3:3
    chip-ID: 046d:0843 class-ID: 0102 serial: <filter>
  API: ALSA v: k6.12.48-1-MANJARO status: kernel-api with: aoss
    type: oss-emulator tools: alsactl,alsamixer,amixer
  Server-1: PipeWire v: 1.4.8 status: active with: 1: pipewire-pulse
    status: active 2: wireplumber status: active 3: pipewire-alsa type: plugin
    4: pw-jack type: plugin tools: pactl,pw-cat,pw-cli,wpctl
Network:
  Device-1: Realtek RTL8125 2.5GbE vendor: ASUSTeK driver: r8169 v: kernel
    pcie: gen: 2 speed: 5 GT/s lanes: 1 port: e000 bus-ID: 05:00.0
    chip-ID: 10ec:8125 class-ID: 0200
  IF: enp5s0 state: down mac: <filter>
  Device-2: Intel I211 Gigabit Network vendor: ASUSTeK driver: igb v: kernel
    pcie: gen: 1 speed: 2.5 GT/s lanes: 1 port: d000 bus-ID: 06:00.0
    chip-ID: 8086:1539 class-ID: 0200
  IF: enp6s0 state: down mac: <filter>
  Device-3: Intel Wi-Fi 6 AX200 driver: iwlwifi v: kernel pcie: gen: 2
    speed: 5 GT/s lanes: 1 bus-ID: 07:00.0 chip-ID: 8086:2723 class-ID: 0280
  IF: wlp7s0 state: up mac: <filter>
  IF-ID-1: virbr0 state: down mac: <filter>
  Info: services: NetworkManager, smbd, systemd-timesyncd, wpa_supplicant
Bluetooth:
  Device-1: Intel AX200 Bluetooth driver: btusb v: 0.8 type: USB rev: 2.0
    speed: 12 Mb/s lanes: 1 mode: 1.1 bus-ID: 1-6:5 chip-ID: 8087:0029
    class-ID: e001
  Report: btmgmt ID: hci0 rfk-id: 1 state: up address: N/A
RAID:
  Supported mdraid levels: raid1
  Device-1: md127 maj-min: 9:127 type: mdraid level: mirror status: active
    size: 513.9 MiB
  Info: report: 2/2 UU blocks: 526272 chunk-size: N/A super-blocks: 1.0
  Components: Online:
  0: nvme0n1p1 maj-min: 259:2 size: 514 MiB
  1: nvme1n1p1 maj-min: 259:5 size: 514 MiB
  Device-2: zbigdata type: zfs status: ONLINE level: linear raw:
    size: 7.27 TiB free: 4.13 TiB allocated: 3.14 TiB zfs-fs: size: 7.14 TiB
    free: 4 TiB
  Components: Online:
  1: sdb maj-min: 8:16 size: 7.28 TiB
  Device-3: zhome type: zfs status: ONLINE level: linear raw: size: 464 GiB
    free: 165 GiB allocated: 299 GiB zfs-fs: size: 449.69 GiB free: 150.9 GiB
  Components: Online:
  1: sda maj-min: 8:0 size: 465.76 GiB
  Device-4: zroot type: zfs status: ONLINE level: mirror-0 raw: size: 888 GiB
    free: 627 GiB allocated: 261 GiB zfs-fs: size: 860.71 GiB free: 599.12 GiB
  Components: Online:
  1: nvme0n1p3 maj-min: 259:4 size: 895.01 GiB
  2: nvme1n1p3 maj-min: 259:7 size: 895.01 GiB
Drives:
  Local Storage: total: raw: 9.55 TiB usable: 8.49 TiB used: 3.16 TiB (37.2%)
  SMART Message: Unable to run smartctl. Root privileges required.
  ID-1: /dev/nvme0n1 maj-min: 259:0 vendor: Corsair model: Force MP600
    size: 931.51 GiB block-size: physical: 512 B logical: 512 B speed: 63.2 Gb/s
    lanes: 4 tech: SSD serial: <filter> fw-rev: EGFM13.0 temp: 41.9 C
    scheme: GPT
  ID-2: /dev/nvme1n1 maj-min: 259:1 vendor: Corsair model: Force MP600
    size: 931.51 GiB block-size: physical: 512 B logical: 512 B speed: 63.2 Gb/s
    lanes: 4 tech: SSD serial: <filter> fw-rev: EGFM13.0 temp: 37.9 C
    scheme: GPT
  ID-3: /dev/sda maj-min: 8:0 vendor: Samsung model: SSD 860 EVO 500GB
    size: 465.76 GiB block-size: physical: 512 B logical: 512 B speed: 6.0 Gb/s
    tech: SSD serial: <filter> fw-rev: 1B6Q scheme: GPT
  ID-4: /dev/sdb maj-min: 8:16 vendor: Seagate model: ST8000DX001-3GK101
    size: 7.28 TiB block-size: physical: 4096 B logical: 512 B speed: 6.0 Gb/s
    tech: HDD rpm: 7200 serial: <filter> fw-rev: FC03 scheme: GPT
Partition:
  ID-1: / raw-size: N/A size: 849.38 GiB used: 250.26 GiB (29.5%) fs: zfs
    logical: zroot/manjaro/root
  ID-2: /boot raw-size: 512.9 MiB size: 511.9 MiB (99.80%)
    used: 175.5 MiB (34.3%) fs: vfat dev: /dev/md127p1 maj-min: 259:8
  ID-3: /home raw-size: N/A size: 308.21 GiB used: 157.31 GiB (51.0%) fs: zfs
    logical: zhome/manjaro/home
Swap:
  Kernel: swappiness: 60 (default) cache-pressure: 100 (default) zswap: no
  ID-1: swap-1 type: partition size: 36 GiB used: 0 KiB (0.0%) priority: -2
    dev: /dev/nvme0n1p2 maj-min: 259:3
  ID-2: swap-2 type: partition size: 36 GiB used: 0 KiB (0.0%) priority: -3
    dev: /dev/nvme1n1p2 maj-min: 259:6
Sensors:
  System Temperatures: cpu: 45.0 C mobo: 33.0 C
  Fan Speeds (rpm): cpu: 0
Info:
  Memory: total: 64 GiB note: est. available: 62.7 GiB used: 41.75 GiB (66.6%)
  Processes: 705 Power: uptime: 10h 27m states: freeze,mem,disk suspend: deep
    avail: s2idle wakeups: 0 hibernate: platform avail: shutdown, reboot,
    suspend, test_resume image: 25.02 GiB services: org_kde_powerdevil,upowerd
    Init: systemd v: 257 default: graphical tool: systemctl
  Packages: pm: pacman pkgs: 2141 libs: 456 tools: pamac Compilers:
    clang: 20.1.8 gcc: 15.2.1 alt: 14 Shell: Zsh v: 5.9 default: Bash v: 5.3.3
    running-in: konsole inxi: 3.3.39

qemu-desktop version is 10.1.0-1

3

Can you paste the logs of the host while you power up and down the guest. It may be doing something to the host interface.

(You can see them happen in real time with: journalctl -f)

You run Edge in Manjaro?

4

Weird. I cannot exactly test right now cause i work in the guest and cannot reboot. But at least downloads started after the vm is booted are fine.
Win10 guest, Chromium on the host. UFW active and i changed to the old iptables backend for virtsh (that is something you can try).

5

I cannot test this exact scenario - but my immediate thought is a reset of the NetworkManager service - but that is only a guess.

But it could also be a reset of the wifi card. The AX200 in your inxi - make me think of another thread (unsolved) where the user’s onboard AX200 card randomly stop functioning.

In fact that thread involves the exact same MB

You could test this further by using a ethernet cabled connection and assign your default virtual network to the ethernet adapter instead of the wifi.

2 Likes
6

Both should be seen in the journalctl -f, so this is the next step. Please post only the relevant parts and format with <>. You can maximize the terminal before or use also --no-pager to see the lines uncut.

7

Thanks to everyone’s suggestions. I’ll check the real-time log when I have some time to reboot the VM.

I started using it before MS bloated it with AI bulldoodoo :sweat_smile: … I can try if I can replicate it with Firefox though.

Mod edit:- Minor word substitution to help conform with forum policy. No charge.

8

I have it installed as well, though I rarely use it.

Sometimes it’s interesting to see how much M$ have perverted the honourable Chromium, on which it’s based.

9

Indeed, i just tested and it seems network manager is restarting and that is why that happens. After loading VM, the download continues, so the 1 minute pause is not a big deal.

Nov 19 22:29:27 teo-lenovo-v15 systemd-machined[537]: Machine qemu-3-win10 terminated.
Nov 19 22:29:36 teo-lenovo-v15 systemd[1]: NetworkManager-dispatcher.service: Deactivated successfully.
Nov 19 22:29:38 teo-lenovo-v15 bluetoothd[656]: src/profile.c:record_cb() Unable to get Hands-Free Voice gateway SDP record: Host is down
Nov 19 22:29:44 teo-lenovo-v15 bluetoothd[656]: src/profile.c:record_cb() Unable to get Hands-Free Voice gateway SDP record: Host is down
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.5895] manager: (vnet3): new Tun device (/org/freedesktop/NetworkManager/Devices/14)
Nov 19 22:29:46 teo-lenovo-v15 kernel: virbr0: port 1(vnet3) entered blocking state
Nov 19 22:29:46 teo-lenovo-v15 kernel: virbr0: port 1(vnet3) entered disabled state
Nov 19 22:29:46 teo-lenovo-v15 kernel: vnet3: entered allmulticast mode
Nov 19 22:29:46 teo-lenovo-v15 kernel: vnet3: entered promiscuous mode
Nov 19 22:29:46 teo-lenovo-v15 kernel: virbr0: port 1(vnet3) entered blocking state
Nov 19 22:29:46 teo-lenovo-v15 kernel: virbr0: port 1(vnet3) entered listening state
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6038] device (vnet3): state change: unmanaged -> unavailable (reason 'connection-assumed', managed-type: 'external')
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6055] device (vnet3): state change: unavailable -> disconnected (reason 'connection-assumed', managed-type: 'external')
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6065] device (vnet3): Activation: starting connection 'vnet3' (682068e6-eb5c-4918-b82c-10f1fd4fa747)
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6066] device (vnet3): state change: disconnected -> prepare (reason 'none', managed-type: 'external')
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6068] device (vnet3): state change: prepare -> config (reason 'none', managed-type: 'external')
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6070] device (vnet3): state change: config -> ip-config (reason 'none', managed-type: 'external')
Nov 19 22:29:46 teo-lenovo-v15 systemd-machined[537]: New machine qemu-4-win10.
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6070] device (virbr0): bridge port vnet3 was attached
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6071] device (vnet3): Activation: connection 'vnet3' attached as port, continuing activation
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6072] device (vnet3): state change: ip-config -> ip-check (reason 'none', managed-type: 'external')
Nov 19 22:29:46 teo-lenovo-v15 systemd[1]: Started Virtual Machine qemu-4-win10.
Nov 19 22:29:46 teo-lenovo-v15 systemd[1]: Starting Network Manager Script Dispatcher Service...
Nov 19 22:29:46 teo-lenovo-v15 systemd[1]: Started Network Manager Script Dispatcher Service.
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6441] device (vnet3): state change: ip-check -> secondaries (reason 'none', managed-type: 'external')
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6443] device (vnet3): state change: secondaries -> activated (reason 'none', managed-type: 'external')
Nov 19 22:29:46 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587786.6448] device (vnet3): Activation: successful, device activated.
Nov 19 22:29:48 teo-lenovo-v15 avahi-daemon[523]: Joining mDNS multicast group on interface vnet3.IPv6 with address fe80::fc54:ff:feab:ec6c.
Nov 19 22:29:48 teo-lenovo-v15 avahi-daemon[523]: New relevant interface vnet3.IPv6 for mDNS.
Nov 19 22:29:48 teo-lenovo-v15 avahi-daemon[523]: Registering new address record for fe80::fc54:ff:feab:ec6c on vnet3.*.
Nov 19 22:29:48 teo-lenovo-v15 kernel: virbr0: port 1(vnet3) entered learning state
Nov 19 22:29:50 teo-lenovo-v15 NetworkManager[522]: <info>  [1763587790.8321] device (virbr0): carrier: link connected
Nov 19 22:29:50 teo-lenovo-v15 kernel: virbr0: port 1(vnet3) entered forwarding state
Nov 19 22:29:50 teo-lenovo-v15 kernel: virbr0: topology change detected, propagating
Nov 19 22:29:56 teo-lenovo-v15 systemd[1]: NetworkManager-dispatcher.service: Deactivated successfully.
Nov 19 22:30:02 teo-lenovo-v15 dnsmasq-dhcp[834]: DHCPREQUEST(virbr0) 192.168.122.191 52:54:00:ab:ec:6c
Nov 19 22:30:02 teo-lenovo-v15 dnsmasq-dhcp[834]: DHCPACK(virbr0) 192.168.122.191 52:54:00:ab:ec:6c DESKTOP-CABPV6L
1 Like
10

I check the real-time output from journalctl, and it was indeed caused by NetworkManager:

Here’s the log when launching the VM

Nov 21 20:46:31 Tu-PC systemd[2496]: Started 虛擬系統管理器 - Virtual machine viewer/manager.
Nov 21 20:46:47 Tu-PC plasmashell[2721]: error creating screencast "找不到視窗 ID {8bffe29e-8fcf-4088-874a-41de0613c8da}"
Nov 21 20:46:48 Tu-PC systemd[1]: Listening on libvirt logging daemon admin socket.
Nov 21 20:46:48 Tu-PC systemd[1]: Starting libvirt logging daemon...
Nov 21 20:46:49 Tu-PC systemd[1]: Started libvirt logging daemon.
Nov 21 20:46:49 Tu-PC kernel: tun: Universal TUN/TAP device driver, 1.6
Nov 21 20:46:49 Tu-PC kernel: virbr0: port 1(vnet0) entered blocking state
Nov 21 20:46:49 Tu-PC kernel: virbr0: port 1(vnet0) entered disabled state
Nov 21 20:46:49 Tu-PC kernel: vnet0: entered allmulticast mode
Nov 21 20:46:49 Tu-PC kernel: vnet0: entered promiscuous mode
Nov 21 20:46:49 Tu-PC kernel: virbr0: port 1(vnet0) entered blocking state
Nov 21 20:46:49 Tu-PC kernel: virbr0: port 1(vnet0) entered listening state
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0822] manager: (vnet0): new Tun device (/org/freedesktop/NetworkManager/Devices/7)
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0887] device (vnet0): state change: unmanaged -> unavailable (reason 'connection-assumed', managed-type: 'external')
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0890] device (vnet0): state change: unavailable -> disconnected (reason 'connection-assumed', managed-type: 'external')
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0892] device (vnet0): Activation: starting connection 'vnet0' (a29717ae-fcaf-43ac-81e6-53e8c0efe7b8)
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0893] device (vnet0): state change: disconnected -> prepare (reason 'none', managed-type: 'external')
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0894] device (vnet0): state change: prepare -> config (reason 'none', managed-type: 'external')
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0895] device (vnet0): state change: config -> ip-config (reason 'none', managed-type: 'external')
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0897] device (virbr0): bridge port vnet0 was attached
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0897] device (vnet0): Activation: connection 'vnet0' attached as port, continuing activation
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.0899] device (vnet0): state change: ip-config -> ip-check (reason 'none', managed-type: 'external')
Nov 21 20:46:49 Tu-PC systemd[1]: Starting Network Manager Script Dispatcher Service...
Nov 21 20:46:49 Tu-PC libvirtd[2125]: libvirt version: 11.7.0
Nov 21 20:46:49 Tu-PC libvirtd[2125]: hostname: Tu-PC
Nov 21 20:46:49 Tu-PC libvirtd[2125]: Domain id=1 name='Windows_Home' uuid=cfb4dfb0-aacb-45be-9e2c-f73d25c7155c is tainted: deprecated-config (machine type 'pc-q35-6.1')
Nov 21 20:46:49 Tu-PC systemd-machined[1891]: New machine qemu-1-WindowsHome.
Nov 21 20:46:49 Tu-PC systemd[1]: Started Virtual Machine qemu-1-WindowsHome.
Nov 21 20:46:49 Tu-PC systemd[1]: Started Network Manager Script Dispatcher Service.
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.1440] device (vnet0): state change: ip-check -> secondaries (reason 'none', managed-type: 'external')
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.1441] device (vnet0): state change: secondaries -> activated (reason 'none', managed-type: 'external')
Nov 21 20:46:49 Tu-PC NetworkManager[1883]: <info>  [1763722009.1443] device (vnet0): Activation: successful, device activated.
Nov 21 20:46:49 Tu-PC python3[22747]: Warning no automount-inhibiting implementation available
Nov 21 20:46:51 Tu-PC kernel: virbr0: port 1(vnet0) entered learning state
Nov 21 20:46:53 Tu-PC NetworkManager[1883]: <info>  [1763722013.3465] device (virbr0): carrier: link connected
Nov 21 20:46:53 Tu-PC kernel: virbr0: port 1(vnet0) entered forwarding state
Nov 21 20:46:53 Tu-PC kernel: virbr0: topology change detected, propagating
Nov 21 20:46:59 Tu-PC systemd[1]: NetworkManager-dispatcher.service: Deactivated successfully.
Nov 21 20:47:02 Tu-PC python3[22747]: ../gtk/gdk/wayland/gdkcursor-wayland.c:521 cursor image size (98x93) not an integermultiple of scale (2)
Nov 21 20:47:03 Tu-PC dnsmasq-dhcp[2230]: DHCPDISCOVER(virbr0) 52:54:00:db:3b:44
Nov 21 20:47:03 Tu-PC dnsmasq-dhcp[2230]: DHCPOFFER(virbr0) 192.168.122.97 52:54:00:db:3b:44
Nov 21 20:47:03 Tu-PC dnsmasq-dhcp[2230]: DHCPREQUEST(virbr0) 192.168.122.97 52:54:00:db:3b:44
Nov 21 20:47:03 Tu-PC dnsmasq-dhcp[2230]: DHCPACK(virbr0) 192.168.122.97 52:54:00:db:3b:44 QEMU-Windows-Home
Nov 21 20:47:04 Tu-PC smbd[22922]: pam_unix(samba:session): session opened for user o0331dobe(uid=1000) by (uid=0)
Nov 21 20:47:04 Tu-PC smbd[22922]: [2025/11/21 20:47:04.279405,  0] ../../source3/printing/printer_list.c:58(get_printer_list_db)
Nov 21 20:47:04 Tu-PC smbd[22922]:   get_printer_list_db: Failed to open printer_list.tdb

And here’s the log when shutting down the VM

Nov 21 20:52:12 Tu-PC kernel: virbr0: port 1(vnet0) entered disabled state
Nov 21 20:52:12 Tu-PC kernel: vnet0 (unregistering): left allmulticast mode
Nov 21 20:52:12 Tu-PC kernel: vnet0 (unregistering): left promiscuous mode
Nov 21 20:52:12 Tu-PC kernel: virbr0: port 1(vnet0) entered disabled state
Nov 21 20:52:12 Tu-PC NetworkManager[1883]: <info>  [1763722332.2792] device (vnet0): state change: activated -> unmanaged (reason 'unmanaged', managed-type: 'removed')
Nov 21 20:52:12 Tu-PC NetworkManager[1883]: <info>  [1763722332.2793] device (vnet0): released from controller device virbr0
Nov 21 20:52:12 Tu-PC systemd[1]: Starting Network Manager Script Dispatcher Service...
Nov 21 20:52:12 Tu-PC systemd[1]: Started Network Manager Script Dispatcher Service.
Nov 21 20:52:12 Tu-PC systemd[1]: machine-qemu\x2d1\x2dWindowsHome.scope: Deactivated successfully.
Nov 21 20:52:12 Tu-PC systemd[1]: machine-qemu\x2d1\x2dWindowsHome.scope: Consumed 6min 9.188s CPU time, 4.2G memory peak.
Nov 21 20:52:12 Tu-PC systemd-machined[1891]: Machine qemu-1-WindowsHome terminated.
Nov 21 20:52:22 Tu-PC systemd[1]: NetworkManager-dispatcher.service: Deactivated successfully.

Indeed, the interrupting time is very short, but it is annoying when it is interrupted in the middle of downloading a couple of Gbs data.

It would be good if anyone knows a way to get around it.

2 Likes
11

That has never been a thing, losing the host’s network because you powered up or down guests. (It has been working fine in Manjaro for me for about 5 years.)

I use hooks and and many other things a default install doesn’t use. So I have a hard time comparing what’s normal.

I use both bridged and NAT mode for my guests. How did you set up your bridge? This could possibly be taking it down.

Secondly, this probably won’t tell us what we need but what is your default network?

The output of:

sudo virsh net-dumpxml default
1 Like
12

I don’t want to hijack the topic, but since i notice exactly the same will allow myself to add to the logs. In my case i use NAT. virtio adapter with driver from Redhat, UFW firewall with iptables backend, if that matters.

[teo@teo-lenovo-v15 ~]$ sudo virsh net-dumpxml default
[sudo] password for teo: 
<network connections='1'>
  <name>default</name>
  <uuid>44277c4f-175f-4540-a6f5-1b9c4b1e655e</uuid>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:71:cf:54'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254'/>
    </dhcp>
  </ip>
</network>
13

I know when I installed you had to create your own bridge. It appears they are attempting to do that for you. I have more or less the same in my default network.

Doesn’t this bridged interface even work? (virbr0). I know I tried 3 ways before I came up with a way that worked for me. (I did save those commands!)

You could just try taking out that one line if you don’t use it:

Edit via:

sudo virsh net-edit default
14

upon creation of a new VM
you have to specify the network connection.
NAT is the default
but you can specify the bridge virbr0

I never tried to alter it - some wikis said that the bridge was better/faster
but the default NAT works just fine (for me)

1 Like
15

I’m just trying to think of things that could disrupt the host interface. (VMs powering on and off using this default network was one idea..)

I was asking, if they used the bridged connection, does it work? (Whether upon creation or switching it to bridged while powered off.)

The performance difference in this scenario may of mattered decades ago, it doesn’t now. It’s nice to pop a guest out on to your network and act as a server (without port forwarding in). Or many other uses too!

16

I do not remember setting that bridge up at all. It might be a remnant of some previous configuration of some VM i deleted long time ago. I have to test how it will behave without that line but i cannot restart the VM now. Tomorrow.

17

I use exactly the same configuration (NAT mode, virtio adaptor, UFW firewall with iptables backend).

Here’s the output of network setting:

<network>
  <name>default</name>
  <uuid>d7fe4d24-8eed-45f0-a60f-63356646abec</uuid>
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
  <bridge name='virbr0' stp='on' delay='0'/>
  <mac address='52:54:00:8c:73:62'/>
  <ip address='192.168.122.1' netmask='255.255.255.0'>
    <dhcp>
      <range start='192.168.122.2' end='192.168.122.254'/>
    </dhcp>
  </ip>
</network>
18

I have double checked my setup - it is the same as ye all have.

I have tested by starting a virtual machine (not a Windows Machine though) as I don’t run a Windows VM any more - my workplace bought a ThinkCentre M75q with Windows 11 for running Visual Studio IDE.

Then launched Microsoft Edge Developer - started a download of microsoft dotnet package

Back in the VM shut it down - nice and gentle as it is supposed to - no severed connection.

I am thinking a rare issue of specific circumstances appearing at the same time on the same system every time - which leads to the same thoughts ye all have - local configuration.

I don’t see why this happens but as libvirt is the kernel’s virtual machine implementation - it has to be related to the kernel in use - more specifically the network driver stack.

From your inxi it is obvious you run on stable branch - Linux 6.12.48

If you don’t like switching to testing or unstable - you could check if using Linux 6.17.1 (on stable branch) make any difference.

Your system uses AX200 wifi - did you try my earlier suggestion of connecting using ethernet and assigning the ethernet to the virtual bridge network ?

19

I may have started down the wrong road. (But hey, it’s still progress!)

Looking into this further, it appears the virbr0 interface is not the actual bridged interface for guests, just a virtual network bridge for the NAT network. (I thought it was called vnet[0-9] by default.) My bridged interface is called br0, but I know I created that one myself.

I think NetworkManager is causing this disruption as @linux-aarhus says. But I cannot recreate this (and I would have spotted it if it were the case by now).

Just to make sure I know which interface and network is what, and to out-rule actual bridged interfaces.. What is the output of:

ip -br addr
sudo bridge link show

My next step would be leaning towards getting NetworkManager to ignore it:

e.g.

/etc/NetworkManager/conf.d/ignore-virbr0

[keyfile]
unmanaged-devices=interface-name:virbr0
20 
[teo@teo-lenovo-v15 ~]$ ip -br addr
lo               UNKNOWN        127.0.0.1/8 ::1/128 
enp1s0           DOWN           
wlp0s20f3        UP             192.168.0.245/24 2a02:8071:64d1:9d40::4837/128 2a02:8071:64d1:9d40:3f83:294b:d0ff:8178/64 fe80::d341:5862:aefa:de72/64 
virbr0           UP             192.168.122.1/24 
vnet0            UNKNOWN        fe80::fc54:ff:feab:ec6c/64 
[teo@teo-lenovo-v15 ~]$ sudo bridge link show
[sudo] password for teo: 
5: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master virbr0 state forwarding priority 32 cost 2 
[teo@teo-lenovo-v15 ~]$
21

I tried both VM up and down:

When VM is down, here’s the output of ip -br-addr

lo               UNKNOWN        127.0.0.1/8 ::1/128 
enp5s0           DOWN           
enp6s0           DOWN           
wlp7s0           UP             192.168.0.231/24 2001:8001:6018:dc00:feb:3950:6b12:d389/64 fe80::17e8:94ed:b499:c2fa/64 
virbr0           DOWN           192.168.122.1/24

sudo bridge link show reports nothing.

When VM is up:

lo               UNKNOWN        127.0.0.1/8 ::1/128 
enp5s0           DOWN           
enp6s0           DOWN           
wlp7s0           UP             192.168.0.231/24 2001:8001:6018:dc00:feb:3950:6b12:d389/64 fe80::17e8:94ed:b499:c2fa/64 
virbr0           UP             192.168.122.1/24 
vnet0            UNKNOWN        fe80::fc54:ff:fedb:3b44/64

sudo bridge link show

6: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master virbr0 state forwarding priority 32 cost 2

I don’t have a long enough Ethernet cable to test this. :sweat_smile:

I’ll try the NetworkManager config to see if it solves the issue.