Hi, The migration code expects the RAM block name to match between the source and destination. However the backend type may change, so it is possible (so far) to migrate from a hostmem-file to a hostmem-memfd for example.
However, hostmem backends use inconsistent RAM naming, which can cause a name mismatch. hostmem-file and hostmem-memfd use the whole object path as memory name, while -ram use only the object "id". This series adds global property support for objects others than TYPE_DEVICE (only TYPE_USER_CREATABLE for now), and a new compat property "x-use-canonical-path-for-ramblock-id" to hostmem for legacy canonical path names, set to true for -file and -memfd with qemu < 3.1. v2: - replace "qom/user-creatable: add a few helper macros" patch for a more optimized "qom: make user_creatable_complete() specific to UserCreatable" - rename register_global_list() to register_global_properties() - call object_property_set_globals() after post-init - add and use a ObjectClass.set_globals flag, instead of dynamically check object class in object_property_set_globals() - use object "id" in >= 3.1 instead of canonical path, add compat property "x-use-canonical-path-for-ramblock-id" in base hostmem class. Marc-André Lureau (10): qom: make user_creatable_complete() specific to UserCreatable accel: register global_props like machine globals qdev: move qdev_prop_register_global_list() to tests qom/globals: move qdev globals to qom qom/globals: generalize object_property_set_globals() qom/object: set globals when initializing object qom/object: add set_globals flags tests: add user-creatable test to test-qdev-global-props hw/i386: add pc-i440fx-3.1 & pc-q35-3.1 hostmem: use object id for memory region name with >= 3.1 include/hw/compat.h | 11 +- include/hw/i386/pc.h | 2 +- include/hw/qdev-core.h | 20 --- include/hw/qdev-properties.h | 34 +--- include/qom/globals.h | 32 ++++ include/qom/object.h | 1 + include/qom/object_interfaces.h | 4 +- include/sysemu/hostmem.h | 3 +- accel/accel.c | 9 +- backends/hostmem-file.c | 8 +- backends/hostmem-memfd.c | 2 +- backends/hostmem-ram.c | 9 +- backends/hostmem.c | 30 ++++ hw/core/machine.c | 2 +- hw/core/qdev-properties.c | 97 ----------- hw/core/qdev.c | 7 +- hw/i386/pc_piix.c | 15 +- hw/i386/pc_q35.c | 13 +- hw/misc/ivshmem.c | 2 +- hw/virtio/virtio-rng.c | 2 +- qom/cpu.c | 2 +- qom/globals.c | 76 +++++++++ qom/object.c | 17 +- qom/object_interfaces.c | 21 ++- target/i386/cpu.c | 2 +- target/sparc/cpu.c | 2 +- ...dev-global-props.c => test-global-props.c} | 150 +++++++++++++++--- vl.c | 6 +- qom/Makefile.objs | 2 +- tests/Makefile.include | 4 +- 30 files changed, 362 insertions(+), 223 deletions(-) create mode 100644 include/qom/globals.h create mode 100644 qom/globals.c rename tests/{test-qdev-global-props.c => test-global-props.c} (71%) -- 2.19.0.271.gfe8321ec05