Re: [Qemu-devel] [PULL 15/19] hw/arm/highbank: don't make sysram 'nomigrate'

[Peter Maydell]

On 26 April 2018 at 23:03, Michael Clark <address@hidden> wrote:
>
>
> On Thu, Apr 26, 2018 at 10:47 PM, Peter Maydell <address@hidden>
> wrote:
>>
>> Currently we use memory_region_init_ram_nomigrate() to create
>> the "highbank.sysram" memory region, and we don't manually
>> register it with vmstate_register_ram(). This currently
>> means that its contents are migrated but as a ram block
>> whose name is the empty string; in future it may mean they
>> are not migrated at all. Use memory_region_init_ram() instead.
>
>
> It is self evident that memory_region_init_ram() implies normal migration.

Yes; using the _nomigrate functions in these files looks odd
but it only looks odd as a result of a refactor we did.

Previously we had:
 * memory_region_init_ram() -- doesn't register the ram for migration
 * everybody has to manually call vmstate_register_ram()
Then we refactored so that:
 * the old memory_region_init_ram() is renamed to _nomigrate()
 * a new memory_region_init_ram() does that plus calls
   vmstate_register_ram() for you
 * callsites that were doing both calls got automatically rewritten
   to call the new memory_region_init_ram()
 * callsites that forgot the vmstate_register_ram() got rewritten
   to call memory_region_init_ram_nomigrate()

So board code that was previously making an easy and hard-to-spot
mistake (forgetting to call vmstate_register_ram()) got rewritten
so the mistake is more obvious (calling memory_region_init_ram_nomigrate
for no good reason).

thanks
-- PMM