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Date: Wed, 14 Mar 2012 12:59:36 +0200
From: Gleb Natapov <gleb@redhat.com>
To: Wen Congyang <wency@cn.fujitsu.com>
Cc: Avi Kivity <avi@redhat.com>, Amit Shah <amit.shah@redhat.com>,
        "Daniel P. Berrange" <berrange@redhat.com>,
        kvm list <kvm@vger.kernel.org>, qemu-devel <qemu-devel@nongnu.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
        Jan Kiszka <jan.kiszka@siemens.com>
Subject: Re: [PATCH 0/2 v3] kvm: notify host when guest panicked
Message-ID: <20120314105936.GX2304@redhat.com>
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On Wed, Mar 14, 2012 at 06:58:47PM +0800, Wen Congyang wrote:
> At 03/14/2012 06:52 PM, Avi Kivity Wrote:
> > On 03/14/2012 12:52 PM, Wen Congyang wrote:
> >>>
> >>>> If so, is this channel visible to guest userspace? If the channle is visible to guest
> >>>> userspace, the program running in userspace may write the same message to the channel.
> >>>
> >>> Access control is via permissions.  You can have udev scripts assign
> >>> whatever uid and gid to the port of your interest.  By default, all
> >>> ports are only accessible to the root user.
> >>
> >> We should also prevent root user writing message to this channel if it is
> >> used for panicked notification.
> >>
> > 
> > Why?  root can easily cause a panic.
> > 
> 
> root user can write the same message to virtio-serial while the guest is running...
> 
So what?

--
			Gleb.