** Summary changed: - KVM: multiple epoch facility bugs + Ubuntu18.04 - KVM on S390 - Multiple epoch facility bugs
-- 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/1755712 Title: Ubuntu18.04 - KVM on S390 - Multiple epoch facility bugs Status in Ubuntu on IBM z Systems: Triaged Status in linux package in Ubuntu: New Bug description: The bionic 4.15 kernel contains KVM/s390 support for the multiple epoch facility. This code has some bugs which can result in hanging guests when running the guest on a z14 with a recent guest kernel (containing 6e2ef5e4f6cc57344762932d70d38ba4ec65fa8b s390/time: add support for the TOD clock epoch extension) The following upstream commits are necessary to fix the multi epoch facility 0e7def5fb0dc KVM: s390: provide only a single function for setting the tod (fix SCK) 1575767ef3cf KVM: s390: consider epoch index on TOD clock syncs d16b52cb9cdb KVM: s390: consider epoch index on hotplugged CPUs 5fe01793dd95 KVM: s390: take care of clock-comparator sign control As an alternative 4.15.8 also contains these fixes. ---uname output--- 4.15 ---Additional Hardware Info--- Z14 LPAR Machine Type = IBM z14 ---System Hang--- A simple test case to trigger the hang of guests: qemu-system-s390x -drive file=/data/bionic-server- s390x.iso,if=none,id=d1 -nographic -enable-kvm -device virtio-scsi-ccw -device scsi-cd,drive=d1 -m 1G -cpu z14,mepoch=on it hangs just before printing the network dialog. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1755712/+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
