From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: Re: [PATCH 2/2] kvm tools: Add virtio-9p Date: Thu, 26 May 2011 18:30:04 +0300 Message-ID: <1306423804.3065.24.camel@lappy> References: <1305657337-2584-1-git-send-email-levinsasha928@gmail.com> <1305657337-2584-2-git-send-email-levinsasha928@gmail.com> <20110517184023.GC16689@elte.hu> <1305659307.12150.37.camel@sasha> <1305664052.12150.43.camel@sasha> <1305709505.12150.71.camel@sasha> <4DDE6398.107@linux.vnet.ibm.com> <1306420607.3065.20.camel@lappy> <4DDE704E.2010404@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Eric Van Hensbergen , Ingo Molnar , penberg@kernel.org, asias.hejun@gmail.com, prasadjoshi124@gmail.com, gorcunov@gmail.com, kvm@vger.kernel.org To: Venkateswararao Jujjuri Return-path: Received: from mail-wy0-f174.google.com ([74.125.82.174]:54484 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932776Ab1EZPaI (ORCPT ); Thu, 26 May 2011 11:30:08 -0400 Received: by wya21 with SMTP id 21so597333wya.19 for ; Thu, 26 May 2011 08:30:07 -0700 (PDT) In-Reply-To: <4DDE704E.2010404@linux.vnet.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, 2011-05-26 at 08:22 -0700, Venkateswararao Jujjuri wrote: > On 05/26/2011 07:36 AM, Sasha Levin wrote: > > On Thu, 2011-05-26 at 07:28 -0700, Venkateswararao Jujjuri wrote: > >> Any progress on this? May I get more detailed instructions on how > >> you did this trick? Basically booting on 9P/VirtIO. > >> > >> Thanks, > >> JV > >> > > Ofcourse. This change didn't go into tools/kvm/ since we only support > > the legacy 9p2000 protocol at the moment, which means that even though > > we can boot - it's quite unusable to work with. > > > > The trick is pretty simple: You need to name your virtio transport > > "/dev/root" (I think it's currently named "local" in qemu). Once it's > > named this way, boot with the following kernel cmdline added: > > "root=/dev/root rootflags=rw,trans=virtio,version=9p2000 rootfstype=9p > > rw" (You should be able to change version to one of the 9p2000 > > extensions). > Ah I guess you are making use of rootfstype. > So in this setup basically the virtio transport you create > is /dev/root instead of "kvm_9p" correct? Yes, exactly. > Also your dir will be / ? > > i.e Start KVM with '--virtio-9p /'. ? It can be '/', but I'd suggest against trying to boot your hosts root device within a guest (unless in RO mode maybe). I've mounted a disk image to some directory on the host and booted that directory for testing. > > I've noticed that the transport *has* to be named "/dev/root", naming it > > something else (and adjusting the "root=" parameter) doesn't seem to > > work. > > > > Also, if it's named "/dev/root" I couldn't mount it as a simple > > filesystem from within a guest - not as root. > > > -- Sasha.