From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=39530 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1PhP5E-0001l1-2c
	for qemu-devel@nongnu.org; Mon, 24 Jan 2011 11:16:01 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <aneesh.kumar@linux.vnet.ibm.com>) id 1PhP5B-00043D-Or
	for qemu-devel@nongnu.org; Mon, 24 Jan 2011 11:15:59 -0500
Received: from e23smtp02.au.ibm.com ([202.81.31.144]:48960)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <aneesh.kumar@linux.vnet.ibm.com>) id 1PhP5B-00041n-7N
	for qemu-devel@nongnu.org; Mon, 24 Jan 2011 11:15:57 -0500
Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [202.81.31.246])
	by e23smtp02.au.ibm.com (8.14.4/8.13.1) with ESMTP id p0OGAZca022789
	for <qemu-devel@nongnu.org>; Tue, 25 Jan 2011 03:10:35 +1100
Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139])
	by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id
	p0OGFbMZ2400352
	for <qemu-devel@nongnu.org>; Tue, 25 Jan 2011 03:15:39 +1100
Received: from d23av04.au.ibm.com (loopback [127.0.0.1])
	by d23av04.au.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id
	p0OGFbJb019678
	for <qemu-devel@nongnu.org>; Tue, 25 Jan 2011 03:15:37 +1100
From: "Aneesh Kumar K. V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: Re: [Qemu-devel] Playing with virtfs.
In-Reply-To: <4D3C827A.8080207@landley.net>
References: <4D3C827A.8080207@landley.net>
Date: Mon, 24 Jan 2011 21:45:31 +0530
Message-ID: <87pqrmnuqk.fsf@linux.vnet.ibm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
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: Rob Landley <rob@landley.net>, qemu-devel@nongnu.org

On Sun, 23 Jan 2011 13:33:14 -0600, Rob Landley <rob@landley.net> wrote:
> Using yesterday's -git, following the instructions in
> http://wiki.qemu.org/Documentation/9psetup (which is missing a kernel
> symbol, you need to add CONFIG_VIRTIO_PCI to your kernel too), I managed
> to mount a read-only virtfs filesystem, adding this to the
> qemu-system-x86_64 command line:

With top of the kernel tree 52cfd503ad7176d23a5dd7af3981744feb60622f
I am able to build the kernel without CONFIG_VIRTIO_PCI. What is the
exact error you are finding ?

> 
> -virtfs
> local,security_model=passthrough,mount_tag=kvm,path=/home/landley/9ptest
> 
> And then in the emulated Linux:
> 
>   root@kvm:~# mount -t 9p -o trans=virtio,version=9p2000.L kvm woot
>   root@kvm:~# ls -l woot
>   total 80
>   -rw-r--r-- 1 1000 1000 77874 Jan 22 23:33 config-linux
>   root@kvm:~# cd woot
>   root@kvm:~/woot# touch fred
>   touch: setting times of `fred': No such file or directory
>   root@kvm:~/woot#
> 
> I.E. It seems to work fine read only, but changes are discarded.
> 
> Am I doing something wrong, or is this expected?  (If so, when is write
> support likely to go in?)
> 

Are you running qemu as root ? Using passthrough security model require
the ability to change the ownership of the file. Otherwise you can use
security=none, but the credentials with which files are created will
not be correct. 

-aneesh