This patchset adds support in s390 for a pool of standby memory, which can be set online/offline by the guest (ie, via chmem). The standby pool of memory is allocated as the difference between the initial memory setting and the maxmem setting. As part of this work, additional results are provided for the Read SCP Information SCLP, and new implentation is added for the Read Storage Element Information, Attach Storage Element, Assign Storage and Unassign Storage SCLPs, which enables the s390 guest to manipulate the standby memory pool.
This patchset is based on work originally done by Jeng-Fang (Nick) Wang. Sample qemu command snippet: qemu -machine s390-ccw-virtio -m 1024M,maxmem=2048M,slots=32 -enable-kvm This will allocate 1024M of active memory, and another 1024M of standby memory. Example output from s390-tools lsmem: ============================================================================= 0x0000000000000000-0x000000000fffffff 256 online no 0-127 0x0000000010000000-0x000000001fffffff 256 online yes 128-255 0x0000000020000000-0x000000003fffffff 512 online no 256-511 0x0000000040000000-0x000000007fffffff 1024 offline - 512-1023 Memory device size : 2 MB Memory block size : 256 MB Total online memory : 1024 MB Total offline memory: 1024 MB The guest can dynamically enable part or all of the standby pool via the s390-tools chmem, for example: chmem -e 512M And can attempt to dynamically disable: chmem -d 512M Changes for v8: * In unassign_storage, replace memory_region_destroy with a call to object_unparent. We need a call to object_unparent here, as the region may be re-used later. Changes for v7: * Added patch to enforce the same memory alignments in s390-virtio.c, so that shared code (like sclp) doesn't need to be dual paths. Changes for v6: * Fix in sclp.h - DeviceState parent --> SysBusDevice parent in struct sclpMemoryHotplugDev. * Fix in assign_storage - int this_subregion_size, should be uint64_t. * Added information on how to test in the cover letter. Changes for v5: * Since ACPI memory hotplug is now in, removed Igor's patches from this set. * Updated sclp.c to use object_resolve_path() instead of object_property_find(). Matthew Rosato (4): sclp-s390: Add device to manage s390 memory hotplug virtio-ccw: Include standby memory when calculating storage increment s390-virtio: Apply same memory boundaries as virtio-ccw sclp-s390: Add memory hotplug SCLPs hw/s390x/s390-virtio-ccw.c | 46 +++++-- hw/s390x/s390-virtio.c | 15 ++- hw/s390x/sclp.c | 289 +++++++++++++++++++++++++++++++++++++++++++- include/hw/s390x/sclp.h | 20 +++ qemu-options.hx | 3 +- target-s390x/cpu.h | 18 +++ target-s390x/kvm.c | 5 + 7 files changed, 375 insertions(+), 21 deletions(-) -- 1.7.9.5
