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

[Lei Li]

On 08/28/2013 02:37 PM, 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.

I'll see if could find way to export RAMBlock as well. If not, will represent
it like RDMA did.
Replacing the block_offset argument of save_page with MemoryRegion might be a
good idea, I will give it a try.

Thanks for your suggestions!

> Paolo


--
Lei