------- Comment From c...@ibm.com 2025-03-12 11:18 EDT------- Hi, I tested virtio-mem-ccw on Ubuntu Plucky 25.04.
First I installed Ubuntu 24.10 and upgraded to 25.04 via `do-release- upgrade --devel-release`, on both the host and guest. Note that doing so did not upgrade the kernel past 6.12, which is incompatible with virtio- mem-ccw, as support for s390 virtio-mem is not introduced until Merge tag 's390-6.13-1'. So I upgraded to a 6.14 "cowboy build" that I obtained via `add-apt-repository ppa:canonical-kernel-team/unstable`. Issuing `apt update && apt full-upgrade && apt-get dist-upgrade` appeared to only update the kernel and no other packages, from what I could tell. I saw success hotplugging and hotunplugging a device via QMP commands `device_add` and `device_del`. However, I saw failure when doing so via `virsh attach-device` instead. Below is the error. ``` ? virsh attach-device u2410 ~/virtio-mem.xml error: Failed to attach device from /root/virtio-mem.xml error: internal error: unable to execute QEMU command 'device_add': PCI-attached virtio based memory devices not supported ? cat ~/virtio-mem.xml <memory model='virtio-mem'> <target> <size unit='GiB'>10</size> <block unit='MiB'>2</block> <requested unit='KiB'>0</requested> </target> <address type='ccw'/> </memory> ``` I also ran some regression testing. All test cases passed. These tests defined various virtio-mem-ccw devices in domain XML, resize devices, hot(un)plug devices, and kexec the system before/after/during various virtio-mem-ccw operations. (Note that these regression tests online all hotplugged memory in the kernel to ZONE_MOVABLE, as dictated by kernel cmdline arg `memhp_default_state=online_movable`. The virtio-mem doc mentions that using this policy is the most reliable in terms of the success of shrink operations. More info can be found at https://virtio-mem.gitlab.io/user- guide/user-guide-linux.html#memory_onlining) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2097886 Title: [25.04 FEAT] [VS2027] KVM: Enable virtio-mem support - libvirt part To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/2097886/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
