qemu-system looses network connectivity even at low loads

[Thomas Schweikle]

qemu-system-x86 looses network connectivity even at low loads. Using qemu running VM with
- FreeBSD 11, 12, 13, 14
- Ubuntu 20.04, 20.10, 21.04, 21.10, 22.04(beta)
- Fedora 34, 35, rawhide
- debian stable, testing, unstable, debian-kfreebsd, debian-hurd
- gentoo
- haiku
- OpenBSD 6.9, 7.0
- NetBSD 9, 10
- kali
- OpenIndiana
- openSUSE leap, tumbleweed

After starting a simple task like updating the VMs system with
- apt update; apt upgrade; apt full-upgrade
- zypper update; zypper upgrade
- dup upgrade

The established ssh-session gets lost and it is not possible to establish it again. The further running VM does not act on ping -- it does not even receive the icmp echo request. Seems the bridge is the problem. The VM looses connection to the virtual bridge and it is impossible to reenable it.

ProblemType: Bug
DistroRelease: Ubuntu 21.10
Package: qemu-system-x86 1:6.0+dfsg-2expubuntu1.2
ProcVersionSignature: Ubuntu 5.13.0-37.42-generic 5.13.19
Uname: Linux 5.13.0-37-generic x86_64
ApportVersion: 2.20.11-0ubuntu71
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: XFCE
Date: Sun Mar 20 13:55:42 2022
InstallationDate: Installed on 2011-10-19 (3804 days ago)
InstallationMedia: Xubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
MachineType: Acer TravelMate P643-M
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.13.0-37-generic root=/dev/mapper/vg-root ro elevator=deadline splash acpi=force reboot=bios ipv6.disable=1 crashkernel=384M-2G:128M,2G-:256M vt.handoff=7
SourcePackage: qemu
UpgradeStatus: Upgraded to impish on 2019-04-27 (1057 days ago)
dmi.bios.date: 10/21/2013
dmi.bios.release: 2.15
dmi.bios.vendor: Phoenix Technologies Ltd.
dmi.bios.version: V2.15
dmi.board.asset.tag: No Asset Tag
dmi.board.name: TravelMate P643-M
dmi.board.vendor: Acer
dmi.board.version: V2.15
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: Acer
dmi.chassis.version: V2.15
dmi.ec.firmware.release: 1.19
dmi.modalias: dmi:bvnPhoenixTechnologiesLtd.:bvrV2.15:bd10/21/2013:br2.15:efr1.19:svnAcer:pnTravelMateP643-M:pvrV2.15:rvnAcer:rnTravelMateP643-M:rvrV2.15:cvnAcer:ct9:cvrV2.15:skuTravelMateP643-M_0681_2.15:
dmi.product.family: TravelMate P643-M
dmi.product.name: TravelMate P643-M
dmi.product.sku: TravelMate P643-M_0681_2.15
dmi.product.version: V2.15
dmi.sys.vendor: Acer

[Paride Legovini (paride)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

There isn't really enough information here for a developer to confirm this issue is a bug, or to begin working on it, so I am marking this bug Incomplete for now.

If you can provide exact steps so that a developer can reproduce the original problem, then please add them to this bug and change the status back to New. Especially important here is the reasoning that brought you to conclude that it's qemu at fault, and not the specific network setup of your host system. Thanks!

[Launchpad Janitor (janitor)]

[Expired for qemu (Ubuntu) because there has been no activity for 60 days.]