Re: [Qemu-devel] [RFC PATCH] migration: discard RAMBlocks of type ram_device

[Peter Maydell]

On 12 April 2018 at 08:02, Cédric Le Goater <address@hidden> wrote:
> On 04/11/2018 09:21 PM, Dr. David Alan Gilbert wrote:
>> Interestingly, your patch comes less than 2 weeks after Lai Jiangshan's
>>  'add capability to bypass the shared memory'
>>    https://lists.nongnu.org/archive/html/qemu-devel/2018-03/msg07511.html
>
> I missed that.
>
>> which is the only other case I think we've got of someone trying to
>> avoid transmitting a block.
>>
>> We should try and merge the two sets to make them consistent; you've
>> covered some more cases (the other patch wasn't expected to work with
>> Postcopy anyway).
>> (At this rate then we can expect another 20 for the year....)
>>
>> We should probably have:
>>    1) A     bool is_migratable_block(RAMBlock *)
>>    2) A RAMBLOCK_FOREACH_MIGRATABLE(block)  macro that is like
>> RAMBLOCK_FOREACH but does the call to is_migratable_block
>>
>> then the changes should be mostly pretty tidy.

We also want this so we can enable migration when the
"mmio-exec" feature is being used without accidentally
trying to migrate the ramblock used for execute-from-device:
 http://lists.gnu.org/archive/html/qemu-devel/2017-07/msg05237.html

thanks
-- PMM