RE: [Xen-devel] foreign mapping destructor

["King, Steven R" <steven.r.king@xxxxxxxxx>]

Thanks Keir, this is helpful -- Just to be definitive: the only
*required* activity in the destructor is to unmap the foreign page from
the domain.  Additional cleanup is use case dependent.

Correct?

-----Original Message-----
From: Keir Fraser [mailto:Keir.Fraser@xxxxxxxxxxxx] 
Sent: Friday, December 02, 2005 2:19 AM
To: King, Steven R
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-devel] foreign mapping destructor


On 2 Dec 2005, at 00:54, King, Steven R wrote:

> The SetPageForeign() macro takes a pointer to a destructor function.
> Can someone please explain the responsibilities of this destructor?
> Thanks for your time,

The 'Foreign' in this context is supposed to refer to a foreign heap. 
That is, the page was not originally allocated from page_alloc.c. So the
destructor is entirely responsible for cleaning up that page of memory
(e.g., in netback.c it unmaps a domU page and sends a packet-transmitted
response to the domU netfront driver). After calling the destructore,
page_alloc.c will not touch that page any more (it will immediately
bail).

  -- Keir

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel