Based on current master. There is really not much left to do on s390x, because virtio-mem already implements most things we need today (e.g., early-migration, unplugged-inaccessible). The biggest part of this series is just doing what we do with virtio-pci, wiring it up in the machine hotplug handler and ... well, messing with the physical memory layout where we can now exceed initial RAM size and have sparsity (memory holes).
I tested a lot of things, including: * Memory hotplug/unplug * Device hotplug/unplug * System resets / reboots * Migrate to/from file (including storage attributes under KVM) * Basic live migration * Basic postcopy live migration More details on how to use it on s390x -- which is pretty much how we use it on other architectures, except s/virtio-mem-pci/virtio-mem-ccw/ --- is in the last patch. This series introduces a new diag(500) "STORAGE LIMIT" subcode that will be documented in the kernel and at [2] once this+kernel part go upstream. There are not many s390x-specific virtio-mem future work items, except: * Storage attribute migration might be improved * We might want to reset storage attributes of unplugged memory (might or might not be required for upcoming page table reclaim in Linux; TBD) The Linux driver is available at [3]. [1] https://lkml.kernel.org/r/20240906101658.514470-1-pbonz...@redhat.com [2] https://gitlab.com/davidhildenbrand/s390x-os-virt-spec [3] https://lkml.kernel.org/r/20240910191541.2179655-6-da...@redhat.com v1 -> v2: * "s390x/s390-virtio-hcall: prepare for more diag500 hypercalls" - Turn handle_diag_500() into a void function - Inject PGM_SPECIFICATION from handle_diag_500() directly * "s390x/s390-virtio-ccw: move setting the maximum guest size from sclp to machine code" - Move code to a new function to make further changes easier - Adjust s390_pv_vm_try_disable_async() to stay in sync with the maxram->ram change * "s390x: introduce s390_get_memory_limit()" - Store limit in machine - Move s390_set_memory_limit() from target code into machine code * "s390x/s390-hypercall: introduce DIAG500 STORAGE_LIMIT" - Move handling into a separate function now that we lookup the machine * "s390x/s390-stattrib-kvm: prepare for memory devices and sparse memory layouts" - Adjust to s390_get_memory_limit() changes * "s390x/s390-skeys: prepare for memory devices" - Adjust to s390_get_memory_limit() changes * "s390x/pv: prepare for memory devices" - Use s390_get_memory_limit() * "s390x: remember the maximum page size" - Store it in the machine - Move s390_set_max_pagesize() from target code into machine code - No need for s390_get_max_pagesize() * "s390x/virtio-ccw: add support for virtio based memory devices" - Move machine wire-up code from virtio-mem patch into this patch - Add stubs to make compilation without virtio-mem work * "s390x: virtio-mem support" - Move machine write-up code to previous patch Cc: Paolo Bonzini <pbonz...@redhat.com> Cc: Thomas Huth <th...@redhat.com> Cc: Halil Pasic <pa...@linux.ibm.com> Cc: Christian Borntraeger <borntrae...@linux.ibm.com> Cc: Eric Farman <far...@linux.ibm.com> Cc: Richard Henderson <richard.hender...@linaro.org> Cc: Nina Schoetterl-Glausch <n...@linux.ibm.com> Cc: Heiko Carstens <h...@linux.ibm.com> Cc: Ilya Leoshkevich <i...@linux.ibm.com> Cc: Janosch Frank <fran...@linux.ibm.com> Cc: "Michael S. Tsirkin" <m...@redhat.com> Cc: Cornelia Huck <coh...@redhat.com> David Hildenbrand (14): s390x/s390-virtio-ccw: don't crash on weird RAM sizes s390x/s390-virtio-hcall: remove hypercall registration mechanism s390x/s390-virtio-hcall: prepare for more diag500 hypercalls s390x: rename s390-virtio-hcall* to s390-hypercall* s390x/s390-virtio-ccw: move setting the maximum guest size from sclp to machine code s390x: introduce s390_get_memory_limit() s390x/s390-hypercall: introduce DIAG500 STORAGE_LIMIT s390x/s390-stattrib-kvm: prepare for memory devices and sparse memory layouts s390x/s390-skeys: prepare for memory devices s390x/s390-virtio-ccw: prepare for memory devices s390x/pv: prepare for memory devices s390x: remember the maximum page size s390x/virtio-ccw: add support for virtio based memory devices s390x: virtio-mem support MAINTAINERS | 5 + hw/s390x/Kconfig | 1 + hw/s390x/meson.build | 6 +- hw/s390x/s390-hypercall.c | 85 +++++++++++ hw/s390x/s390-hypercall.h | 25 ++++ hw/s390x/s390-skeys.c | 6 +- hw/s390x/s390-stattrib-kvm.c | 67 ++++++--- hw/s390x/s390-virtio-ccw.c | 165 ++++++++++++++------- hw/s390x/s390-virtio-hcall.c | 41 ------ hw/s390x/s390-virtio-hcall.h | 25 ---- hw/s390x/sclp.c | 17 +-- hw/s390x/virtio-ccw-md-stubs.c | 24 +++ hw/s390x/virtio-ccw-md.c | 153 +++++++++++++++++++ hw/s390x/virtio-ccw-md.h | 44 ++++++ hw/s390x/virtio-ccw-mem.c | 226 +++++++++++++++++++++++++++++ hw/s390x/virtio-ccw-mem.h | 34 +++++ hw/virtio/Kconfig | 1 + hw/virtio/virtio-mem.c | 4 +- include/hw/s390x/s390-virtio-ccw.h | 4 + target/s390x/cpu-sysemu.c | 15 -- target/s390x/cpu.h | 2 - target/s390x/kvm/kvm.c | 18 +-- target/s390x/kvm/pv.c | 2 +- target/s390x/tcg/misc_helper.c | 7 +- 24 files changed, 782 insertions(+), 195 deletions(-) create mode 100644 hw/s390x/s390-hypercall.c create mode 100644 hw/s390x/s390-hypercall.h delete mode 100644 hw/s390x/s390-virtio-hcall.c delete mode 100644 hw/s390x/s390-virtio-hcall.h create mode 100644 hw/s390x/virtio-ccw-md-stubs.c create mode 100644 hw/s390x/virtio-ccw-md.c create mode 100644 hw/s390x/virtio-ccw-md.h create mode 100644 hw/s390x/virtio-ccw-mem.c create mode 100644 hw/s390x/virtio-ccw-mem.h -- 2.46.1
