From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: obtaining machine frame number
Date: Wed, 24 Aug 2011 16:10:08 -0400
Message-ID: <20110824201008.GA26526@dumpdata.com>
References: <CAL3tnx4iVy41N-8q2yCdUV93xnyRa5vYWNfTTtHDKDdK885d+Q@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <xen-devel-bounces@lists.xensource.com>
Content-Disposition: inline
In-Reply-To: <CAL3tnx4iVy41N-8q2yCdUV93xnyRa5vYWNfTTtHDKDdK885d+Q@mail.gmail.com>
List-Unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xensource.com>
List-Help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-Subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
Sender: xen-devel-bounces@lists.xensource.com
Errors-To: xen-devel-bounces@lists.xensource.com
To: Eli Cohen <eli@dev.mellanox.co.il>
Cc: xen-devel@lists.xensource.com
List-Id: xen-devel@lists.xenproject.org

On Sun, Aug 21, 2011 at 06:20:07PM +0300, Eli Cohen wrote:
> Hi list,
> I am trying to allocate a page at a Linux guest and and obtain the
> machine frame number for that page. Then I want to pass the mfn to

OK, use the pci_map_page API - that should give you the MFN
if you are doing this within a PV guest.

> dom0 (I need to use xen store since I have my own mechanism to
> communicate between guests and dom0) and obtain a struct page for it
> (how?) and then dma map it to a pci device. Can some say if/how can

Uh, ..
> this be done?

Why don't you do what the blkback/blkfront is doing. The blkback
is using m2p_add_override to map the local 'struct page' to
that MFN and then that 'struct page' has the guests' MFN
under it.