Note that, while this symptom is seemingly only reproducible with >= 4.10 (hwe-y), there is another symptom of this problem that is reproducible with 4.4 (hwe-x). That symptom is that VMs will hang during teardown - easily reproducible using a parallel VM start/stop test. I'll therefore mark this as impacting >= xenial.
** Also affects: linux (Ubuntu Xenial) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Zesty) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Yakkety) Importance: Undecided Status: New ** Changed in: linux (Ubuntu Xenial) Status: New => Confirmed ** Changed in: linux (Ubuntu Yakkety) Status: New => Confirmed ** Changed in: linux (Ubuntu Zesty) Status: New => Confirmed ** Changed in: linux (Ubuntu) Importance: Undecided => High ** Changed in: linux (Ubuntu Xenial) Importance: Undecided => High ** Changed in: linux (Ubuntu Yakkety) Importance: Undecided => High ** Changed in: linux (Ubuntu Zesty) Importance: Undecided => High ** Description changed: - This is a followup of an earlier thread/bug that we have narrowed down - to an incompatibility/issue with vhost support in qemu-efi. Without - vhost=on qemu seems to be working fine. + [Impact] + VMs can cause interrupts to be disabled on the host CPU, resulting in hangs. - I have tested several edk2 firmwares: - - xenial - - zesty - - Fedora: ftp://195.220.108.108/linux/fedora-secondary/development/rawhide/Everything/aarch64/os/Packages/e/edk2-aarch64-20170209git296153c5-2.fc26.noarch.rpm + [Test Case] + See Comment #1. - I have also tested with different guests: - - cirros: https://download.cirros-cloud.net/daily/20161201/cirros-d161201-aarch64-disk.img - - ubuntu xenial: https://cloud-images.ubuntu.com/xenial/current/xenial-server-cloudimg-arm64-uefi1.img - - The test steps are simple enough. A tap device is needed, qemu-kvm, - qemu-efi need to be installed. The UEFI iamge is run as shown in the - launch.sh script, the tap device is used in vhost=on mode. - - Also note that the QEMU_EFI.fd binary needs to be padded up to 64M: - dd if=/dev/zero of=AAVMF_CODE.fd bs=1M count=64 - dd if=QEMU_EFI.fd of=AAVMF_CODE.fd conv=notrunc - - - The result was always the same, the node crashing with soft-lockups when qemu was attempting to boot the kernel. - - I will attach all the relevant information shortly. + [Regression Risk] + (TBD, once proposed patches are finalized) -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1673564 Title: ThunderX: soft lockup on 4.8+ kernels when running qemu-efi with vhost=on Status in linux package in Ubuntu: Confirmed Status in linux source package in Xenial: Confirmed Status in linux source package in Yakkety: Confirmed Status in linux source package in Zesty: Confirmed Bug description: [Impact] VMs can cause interrupts to be disabled on the host CPU, resulting in hangs. [Test Case] See Comment #1. [Regression Risk] (TBD, once proposed patches are finalized) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1673564/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp