From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([140.186.70.92]:56201)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <jan.kiszka@siemens.com>) id 1QwVun-0005XF-EC
	for qemu-devel@nongnu.org; Thu, 25 Aug 2011 05:07:58 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <jan.kiszka@siemens.com>) id 1QwVul-0008Mz-Ce
	for qemu-devel@nongnu.org; Thu, 25 Aug 2011 05:07:57 -0400
Received: from goliath.siemens.de ([192.35.17.28]:28752)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <jan.kiszka@siemens.com>) id 1QwVuk-0008MO-VL
	for qemu-devel@nongnu.org; Thu, 25 Aug 2011 05:07:55 -0400
Message-ID: <4E5610E7.1030609@siemens.com>
Date: Thu, 25 Aug 2011 11:07:51 +0200
From: Jan Kiszka <jan.kiszka@siemens.com>
MIME-Version: 1.0
References: <cover.1314033132.git.jan.kiszka@siemens.com>
	<3d9d904a1e4939a147f8954c9e0d4cdaf3d44c31.1314033132.git.jan.kiszka@siemens.com>
	<4E55F799.2050103@redhat.com>
In-Reply-To: <4E55F799.2050103@redhat.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH v3 5/6] vga: Use linear mapping + dirty
 logging in chain 4 memory access mode
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/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: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Avi Kivity <avi@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>, qemu-devel <qemu-devel@nongnu.org>, Gerd Hoffmann <kraxel@redhat.com>

On 2011-08-25 09:19, Avi Kivity wrote:
> On 08/22/2011 08:12 PM, Jan Kiszka wrote:
>> Most VGA memory access modes require MMIO handling as they demand weird
>> logic to get a byte from or into the video RAM. However, there is one
>> exception: chain 4 mode with all memory planes enabled for writing. This
>> mode actually allows lineary mapping, which can then be combined with
>> dirty logging to accelerate KVM.
>>
>> This patch accelerates specifically VBE accesses like they are used by
>> grub in graphical mode. Not only the standard VGA adapter benefits from
>> this, also vmware and spice in VGA mode.
>>
>>
> 
> On which version of grub does this work?  This isn't having any effect 
> on my Fedora grub.

It's both grub1 (0.97) in graphical mode as used by OpenSUSE 11.4 and
grub2 (1.99-rc1) of Ubuntu 11.04.

Is Fedora's grub still slow or was it already fast before? Which Fedora?

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux