From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=52056 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1PSAaY-0004g7-PK
	for qemu-devel@nongnu.org; Mon, 13 Dec 2010 10:45:23 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <hch@lst.de>) id 1PSAaQ-0008QR-ER
	for qemu-devel@nongnu.org; Mon, 13 Dec 2010 10:45:15 -0500
Received: from verein.lst.de ([213.95.11.210]:46070)
	by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from <hch@lst.de>)
	id 1PSAaQ-0008QK-5c
	for qemu-devel@nongnu.org; Mon, 13 Dec 2010 10:45:14 -0500
Date: Mon, 13 Dec 2010 16:45:12 +0100
From: Christoph Hellwig <hch@lst.de>
Subject: Re: [Qemu-devel] ]PATCH 0/7] add TRIM/UNMAP support, v3
Message-ID: <20101213154512.GB5730@lst.de>
References: <20101210150038.GA30990@lst.de>
	<AANLkTikugwA7T-RbvKBec28O75Bun8kDxJydVDsGVHnr@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <AANLkTikugwA7T-RbvKBec28O75Bun8kDxJydVDsGVHnr@mail.gmail.com>
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.nongnu.org/archive/html/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: Stefan Hajnoczi <stefanha@gmail.com>
Cc: qemu-devel@nongnu.org

On Sun, Dec 12, 2010 at 03:28:14PM +0000, Stefan Hajnoczi wrote:
> Do you have qemu-io support for discard?

Now that you wrote it we have the support :)

> Any hints on testing this?  A recent guest kernel and ext -o discard
> might exercise the code but I haven't tried yet.

Anything that submits a discard in the guest is fine.  The simples thing
to test are the various mkfs tools, as they do a whole device discard.
Also -o discard for various Linux filesystem works, Mark Lord's wiper.sh
script, or any Windows 7 installation.