From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1LCd25-0005nt-4T
	for qemu-devel@nongnu.org; Tue, 16 Dec 2008 11:44:29 -0500
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1LCd24-0005mb-4c
	for qemu-devel@nongnu.org; Tue, 16 Dec 2008 11:44:28 -0500
Received: from [199.232.76.173] (port=59099 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1LCd23-0005mQ-UC
	for qemu-devel@nongnu.org; Tue, 16 Dec 2008 11:44:28 -0500
Received: from mail-bw0-f12.google.com ([209.85.218.12]:60549)
	by monty-python.gnu.org with esmtp (Exim 4.60)
	(envelope-from <blauwirbel@gmail.com>) id 1LCd23-0001ED-Jk
	for qemu-devel@nongnu.org; Tue, 16 Dec 2008 11:44:27 -0500
Received: by bwz5 with SMTP id 5so6012632bwz.10
	for <qemu-devel@nongnu.org>; Tue, 16 Dec 2008 08:44:25 -0800 (PST)
Message-ID: <f43fc5580812160835u4eb247ecw6b1200c0979c19f6@mail.gmail.com>
Date: Tue, 16 Dec 2008 18:35:08 +0200
From: "Blue Swirl" <blauwirbel@gmail.com>
Subject: Re: [Qemu-devel] Re: [PATCH 2 of 5] add can_dma/post_dma for direct IO
In-Reply-To: <200812161630.00400.paul@codesourcery.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
References: <cc5d812eb9369a7ad2ef.1229105804@duo.random>
	<4946D501.4020109@codemonkey.ws>
	<f43fc5580812160757h64dc84aak98c43b29bb63251a@mail.gmail.com>
	<200812161630.00400.paul@codesourcery.com>
Reply-To: qemu-devel@nongnu.org
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.gnu.org/pipermail/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Paul Brook <paul@codesourcery.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>, chrisw@redhat.com, kvm@vger.kernel.org, qemu-devel@nongnu.org, Gerd Hoffmann <kraxel@redhat.com>, Avi Kivity <avi@redhat.com>

On 12/16/08, Paul Brook <paul@codesourcery.com> wrote:
> > The generic resolving API should look something like
>  >
>  > int (*resolve)(target_phys_addr_t address_in, target_phys_addr_t
>  > length_in, target_phys_addr_t &address_out, target_phys_addr_t
>  > &length_out)
>
>
> I don't think this is sufficient. A paged iommu may split a single range into
>  multiple disjoint sections. i.e. we need SG lists.

That's why there is the length_out, it is called repeatedly until the
length is zero or it fails.