------- Comment From [email protected] 2026-09-29 08:22 EDT------- Hi Team,
Tested this on latest Ubuntu 26.10 (Stonking Stingray) and upstream qemu. Issue is NOT Reproducible. ---- Host ---- Kernel : 7.3.0-6-generic Qemu : QEMU emulator version 11.1.50 (v11.1.0-1870-g81ce3a8773) Libvirt : libvirtd (libvirt) 12.0.0 root@ubuntu:~# uname -a Linux ubuntu 7.3.0-6-generic #6-Ubuntu SMP PREEMPT_DYNAMIC Mon Sep 21 17:05:11 UTC 2026 ppc64le GNU/Linux root@ubuntu:~# cat /etc/os-release PRETTY_NAME="Ubuntu Stonking Stingray (development branch)" NAME="Ubuntu" VERSION_ID="26.10" VERSION="26.10 (Stonking Stingray)" VERSION_CODENAME=stonking ID=ubuntu ID_LIKE=debian HOME_URL="https://www.ubuntu.com/"; SUPPORT_URL="https://help.ubuntu.com/"; BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"; PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"; UBUNTU_CODENAME=stonking LOGO=ubuntu-logo root@ubuntu:~# lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 8 On-line CPU(s) list: 0-7 Model name: POWER10 (architected), altivec supported Model: 2.0 (pvr 0082 0200) Thread(s) per core: 8 Core(s) per socket: 1 Socket(s): 1 Virtualization features: Hypervisor vendor: pHyp Virtualization type: para ---- Steps Performed ---- 1) Install latest ubuntu 26.10 Stonking kernel on a Power11 Lpar. 2) compile upstream qemu on the OS 3) make sure the lpar is moved to Power10 compatibility mode (From hmc default profile change the processor compatibility mode to Power10) 4) Start a guest using below command /usr/bin/virt-install --connect=qemu:///system --hvm --accelerate --name 'vm' --machine pseries --memory=10000 --vcpu=10,sockets=1,cores=10,threads=1 --import --nographics --os- variant ubuntu25.10 --serial pty --memballoon model=virtio --controller type=scsi,model=virtio-scsi --disk path=/home/ubuntu-26.10-ppc64le.qcow2,bus=scsi,size=50,format=qcow2 --network=bridge=virbr0,model=virtio --boot emulator=/usr/bin/qemu- system-ppc64 --cdrom /home/ubuntu-26.10-snapshot2-live-server- ppc64el.iso.1 5) Guest started successfully and booted into the OS. lscpu shows power10 inside guest. ---- Guest ---- Kernel : 7.0.0-14-generic guest@guest:~$ lscpu Architecture: ppc64le Byte Order: Little Endian CPU(s): 10 On-line CPU(s) list: 0-9 Model name: POWER10 (architected), altivec supported Model: 2.0 (pvr 0082 0200) Thread(s) per core: 1 Core(s) per socket: 10 Socket(s): 1 --- guest boot logs --- Ubuntu Stonking Stingray (development branch) guest hvc0 guest login: guest Password: Welcome to Ubuntu Stonking Stingray (development branch) (GNU/Linux 7.0.0-14-generic ppc64le) * Documentation: https://docs.ubuntu.com * Management: https://landscape.canonical.com * Support: https://ubuntu.com/pro System information as of Tue Sep 29 12:15:09 PM UTC 2026 System load: 0.22 Processes: 229 Usage of /: 26.6% of 9.75GB Users logged in: 0 Memory usage: 5% IPv4 address for enp0s1: 192.168.122.127 Swap usage: 0% 0 updates can be applied immediately. The programs included with the Ubuntu system are free software; the exact distribution terms for each program are described in the individual files in /usr/share/doc/*/copyright. Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by applicable law. guest@guest:~$ uname -a Linux guest 7.0.0-14-generic #14-Ubuntu SMP PREEMPT_DYNAMIC Mon Apr 13 11:10:37 UTC 2026 ppc64le GNU/Linux guest@guest:~$ Thank you, Tasmiya -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2163620 Title: [Ubuntu 26.10] : KVM guest boot hangs on POWER11 host when processor compatibility mode is set to POWER10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/2163620/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
