This wires up the initial, basic version of virito-mem for s390x. General information about virtio-mem can be found at [1] and in QEMU commit [2]. Patch #5 contains a short example for s390x.
virtio-mem for x86-64 Linux is part of v5.8-rc1. A branch with a s390x prototype can be found at: g...@github.com:davidhildenbrand/linux.git virtio-mem-s390x Note that the kernel should either be compiled via CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE, or "memhp_default_state=online" should be passed on the kernel cmdline. This series can be found at: g...@github.com:davidhildenbrand/qemu.git virtio-mem-s390x Related to s390x, we'll have to tackle migration of storage keys and storage attributes (especially, skipping unplugged parts). Not sure if I am missing something else (any ideas?). For virtio-mem in general, there are a couple of TODOs, e.g., documented in [1] and [2], both in QEMU and Linux. However, the basics are around. I only tested this with fairly small amount of RAM in a z/VM environemnt ... [1] https://virtio-mem.gitlab.io/ [2] 910b25766b33 ("virtio-mem: Paravirtualized memory hot(un)plug") David Hildenbrand (5): s390x: move setting of maximum ram size to machine init s390x: implement diag260 s390x: prepare device memory address space s390x: implement virtio-mem-ccw s390x: initial support for virtio-mem hw/s390x/Kconfig | 1 + hw/s390x/Makefile.objs | 1 + hw/s390x/s390-virtio-ccw.c | 178 ++++++++++++++++++++++++++++- hw/s390x/sclp.c | 32 ++---- hw/s390x/virtio-ccw-mem.c | 165 ++++++++++++++++++++++++++ hw/s390x/virtio-ccw.h | 13 +++ hw/virtio/virtio-mem.c | 2 + include/hw/s390x/s390-virtio-ccw.h | 3 + target/s390x/diag.c | 57 +++++++++ target/s390x/internal.h | 2 + target/s390x/kvm.c | 11 ++ target/s390x/misc_helper.c | 6 + target/s390x/translate.c | 4 + 13 files changed, 449 insertions(+), 26 deletions(-) create mode 100644 hw/s390x/virtio-ccw-mem.c -- 2.26.2