On 5 July 2017 at 13:21, Paolo Bonzini <pbonz...@redhat.com> wrote: > > > On 04/07/2017 19:02, Peter Maydell wrote: >> Many board models and several devices need to create auxiliary >> regions of RAM (in addition to the main lump of 'system' memory), >> to model static RAMs, video memory, ROMs, etc. Currently they do >> this with a sequence like: >> memory_region_init_ram(sram, NULL, "sram", 0x10000, &error_fatal); >> vmstate_register_ram_global(sram); > > Instead of vmstate_register_ram_global, you should use > > vmstate_register_ram(mr, owner); > > You should even do it for all memory regions, probably.
This sounds like a good thing, but it's awkward for migration compatibility, because these callers to memory_region_init_ram() don't call vmstate_register_ram(): hw/arm/highbank.c (a bug) hw/mips/mips_malta.c (region is ro) hw/net/dp3893x.c (prom, ro, contains mac address) hw/pci-host/xilinx-pcie.c (dummy region; migrating wouldn't hurt) backends/hostmem-ram.c (bug, or is migration handled elsewhere?) and if we add an implicit call then we break migration compat for those boards/devices. > Only memory_region_init_ram_device_ptr (which sets mr->ram_device) must > not call vmstate_register_ram. This is a bit ugly because it requires > inlining memory_region_init_ram_ptr into it. > > memory_region_init_ram_from_fd probably needs to be excluded, as well, > based on its sole user. Callers of memory_region_init_ram_from_file() which don't call vmstate_register_ram(): backends/hostmem-ram.c Callers of memory_region_init_ram_ptr() which don't call vmstate_register_ram(): hw/misc/mmio_interface.c -- seems to be an implementation detail of the exceute-from-device support so maybe it doesn't need migration support ?? thanks -- PMM