Re: [Qemu-devel] [PATCH 08/18] migration-local: introduce qemu_fopen_local()

["Michael R. Hines" <mrhines@linux.vnet.ibm.com>]

On 08/28/2013 02:37 AM, Paolo Bonzini wrote:
> Il 28/08/2013 05:26, Lei Li ha scritto:
>>>> RAMBlock structs are not visible outside of exec.c and arch_init.c,
>>>> how did you do this?
>>> Hi Michael,
>>>
>>> Good catch!
>>> Actually this is the 'Known issue' that I listed in the cover
>>> letter, and I planed to ask suggestions on this.
>>>
>>> Currently the implementation of override of the RDMA hook like
>>> save_page for localhost migration needs to have knowledge of
>>> MemoryRegion and RAMBlock, say, when saving ram page, need to know
>>> which RAMBlock the given ram address save_page hook passed is
>>> belong to, or which is the last ram block has been sent. But seems
>>> that such structs can not be exported to the private code in
>>> migration-local.c.
>>>
>>> My guess for now is that there might be two possible ways to handle this:
>>>
>>> 1) Choose another way around, like representation of a RAMBlock and
>>> MemoryRegion from localhost migration perspective. This might need
>>> more work to handle the descriptions.
>>>
>>> 2) It could be exported directly into private code like migration-local.c
>>> through some ways that I don't know yet. I remembered that the
>>> implementation of postcopy migration did this.
>>>
>>> So I'd like to post and ask for your suggestions to make sure it's the
>>> right and best way to handle.
>> Hi Paolo,
>>
>> Any suggestions on this?
> Unlike the RAM constants and migration states, I think exporting
> MemoryRegion (not sure about RAMBlock) is fine.  In fact, replacing the
> save_page hook's block_offset argument with a MemoryRegion would be a
> nice cleanup.
>
> Paolo
>
Sounds like a good plan to me.

Once the localhost patch is fully reviewed - I'll submit a similar patch 
to make use of the exported MemoryRegion.

- Michael