From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43)
	id 1NMgaO-00016B-87
	for qemu-devel@nongnu.org; Mon, 21 Dec 2009 06:38:00 -0500
Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43)
	id 1NMgaI-00011w-UB
	for qemu-devel@nongnu.org; Mon, 21 Dec 2009 06:37:59 -0500
Received: from [199.232.76.173] (port=49005 helo=monty-python.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1NMgaI-00011t-Of
	for qemu-devel@nongnu.org; Mon, 21 Dec 2009 06:37:54 -0500
Received: from tx2ehsobe002.messaging.microsoft.com ([65.55.88.12]:39640
	helo=TX2EHSOBE003.bigfish.com)
	by monty-python.gnu.org with esmtps (TLS-1.0:RSA_ARCFOUR_MD5:16)
	(Exim 4.60) (envelope-from <Andre.Przywara@amd.com>)
	id 1NMgaI-0007Rg-Cq
	for qemu-devel@nongnu.org; Mon, 21 Dec 2009 06:37:54 -0500
Message-ID: <4B2F5DF1.4000701@amd.com>
Date: Mon, 21 Dec 2009 12:37:21 +0100
From: Andre Przywara <andre.przywara@amd.com>
MIME-Version: 1.0
Subject: Re: [Qemu-devel] Re: SVM support in 0.12?
References: <fdaac4d50912171837k2eb2f3a2l81de933dab5b521c@mail.gmail.com>	<fdaac4d50912171839v5dd7b108u1f04cc58f8102cdf@mail.gmail.com>	<F780F0C5-3C21-4D85-820D-80BB4C4B7C62@suse.de>	<fdaac4d50912180852u679d6774o265cd4c324e720ba@mail.gmail.com>	<F9582133-F6D0-48EE-95F3-2FC02474D3AB@suse.de>	<fdaac4d50912210206r48edad93s8ab2b0ba49004208@mail.gmail.com>
	<4B2F4D63.2040801@amd.com>
In-Reply-To: <4B2F4D63.2040801@amd.com>
Content-Type: text/plain; charset="ISO-8859-1"; format=flowed
Content-Transfer-Encoding: 7bit
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: Jun Koi <junkoi2004@gmail.com>
Cc: Alexander Graf <agraf@suse.de>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>

Andre Przywara wrote:
> Jun Koi wrote:
>>>>>>> I am running latest Qemu 0.12-rc. My guest VM runs Linux kernel 
>>>>>>> 2.6.31.
>>>>>>>
>>>>>>> Because Qemu now supports SVM, I expect to see the SVM flag in
>>>>>>> /proc/cpuinfo, but that is not the case.
>>>>>>>
>>>>>>> So it seems SVM support is not enabled by default configuration??
>>>>>>>
>>>>>> My host and guest are both 32 bit Linux, if that matters.
>>>>>>
>>>>>> (And this is pure Qemu, without using KVM or KQemu)
>>>>> Kqemu actually works with svm emulation.
>>>>>
> ...
>>>> qemu -m 500 -cpu qemu32,+svm -cdrom ubuntu.iso
>>>>
>>>> I verified that /proc/cpuinfo has no svm flag. So SVM doesnt work on 
>>>> 32bit
>>>> host.
>>>>
>>>> I will try that with 64bit host to see how it goes.
>>> The host doesn't matter. You can easily run qemu-system-x86_64 on a 
>>> 32-bit
>>> host.
>>>
>>
>> I can confirm that SVM works well on x86-64 target, but fails on i386 
>> target.
> 
> The Linux kernel will only detect SVM if the machine is AMD (see 
> linux-2.6/arch/x86/include/asm/virtext.h:cpu_has_svm())
> So please try:
> $ qemu -m 500 -cpu qemu32,+svm,vendor=AuthenticAMD -cdrom ubuntu.iso
> (because the default vendor for qemu32 is Intel, for qemu64 AMD)

Should have checked this before the post ;-):
qemu32 has a xlevel of 0, so no AMD-defined CPUID leafs will be parsed.
Either fix this explicitly with xlevel=0xa or use athlon as your base 
CPU model:
$ qemu -m 500 -cpu athlon,+svm -cdrom ubuntu.iso

This made my Linux show the SVM flag.

Regards,
Andre.

-- 
Andre Przywara
AMD-OSRC (Dresden)
Tel: x29712