From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41699) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7lTg-0003dC-Gu for qemu-devel@nongnu.org; Wed, 14 Mar 2012 06:31:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S7lTD-0005uk-DJ for qemu-devel@nongnu.org; Wed, 14 Mar 2012 06:30:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1717) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7lTD-0005uR-5C for qemu-devel@nongnu.org; Wed, 14 Mar 2012 06:30:15 -0400 Message-ID: <4F607325.6050607@redhat.com> Date: Wed, 14 Mar 2012 12:29:57 +0200 From: Avi Kivity MIME-Version: 1.0 References: <4F58664D.1070800@cn.fujitsu.com> <4F58943E.1050402@redhat.com> <4F595B31.9090301@cn.fujitsu.com> <4F5DBC26.7060204@cn.fujitsu.com> <4F5DD0FD.9070904@redhat.com> <20120313091843.GB3800@redhat.com> <4F5F25BF.7060100@redhat.com> <4F6056FE.3020202@cn.fujitsu.com> <4F6063C8.8010005@redhat.com> <4F606A7C.9090900@cn.fujitsu.com> <4F606DCC.3020908@redhat.com> <4F60726E.3090807@cn.fujitsu.com> In-Reply-To: <4F60726E.3090807@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/2 v3] kvm: notify host when guest panicked List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wen Congyang Cc: Gleb Natapov , kvm list , Jan Kiszka , qemu-devel , "linux-kernel@vger.kernel.org" , Amit Shah , KAMEZAWA Hiroyuki On 03/14/2012 12:26 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. > >> > > > > Surely there's some kind of access control on channels. > > The virtio-serial depends on more things than touching the hypervisor. So I think touching > the hypervisor is more reliable than using virtio-serial device, and it is very simple and > easy to use. > > If we pass something from guest userspace to host, we can use virtio-serial. But If we pass > something from guest kernelspace to host, I still prefer to touch the hypervisor. There's no argument that it's easier. My concern is different, we're adding more and more stuff to the hypervisor because it's easier, which bloats it. Every time we do it we add to compatibility and security problems. The panic notification is *really* simple, so I don't expect it to cause a lot of problems. But still, if it's possible not to change the hypervisor, we must make an effort in that direction. -- error compiling committee.c: too many arguments to function