This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] [RFC PATCH] allow connecting to xenconsole from remote h

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] [RFC PATCH] allow connecting to xenconsole from remote hosts
From: Muli Ben-Yehuda <muli@xxxxxxxxxx>
Date: Wed, 6 Sep 2006 21:12:22 +0300
Cc: Jimi Xenidis <jimix@xxxxxxxxxxxxxx>, xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Orran Y Krieger <okrieg@xxxxxxxxxx>
Delivery-date: Wed, 06 Sep 2006 11:12:50 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C124CB85.C4D%Keir.Fraser@xxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20060906172240.GB9350@xxxxxxxxxxxxxxxxxx> <C124CB85.C4D%Keir.Fraser@xxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.11
On Wed, Sep 06, 2006 at 07:01:25PM +0100, Keir Fraser wrote:
> On 6/9/06 18:22, "Muli Ben-Yehuda" <muli@xxxxxxxxxx> wrote:
> > - 'noecho' mode, where we discard stuff that we read back from a given
> >   fd after we've just written it there ourselves. Without this you get
> >   every console command echo'd back to you from the pty
> >   immediately. For what it's worth this happens without the socket
> >   support as well, except there we put stdout into raw mode so that
> >   the terminal does the 'echo cancelation'. I didn't find a way to
> >   have the pty not echo everything back at me and I didn't want to
> >   rely on the remote tty being in 'raw' mode, so I implemented it
> >   myself.
> Why is this a problem? In cases where an echo is really not wanted, like in
> a gdb control session, the remote end would not be echoing in the first
> place.

Hmm, are you saying it's not the pty itself that echo's stuff back at
us, it's whatever is on the other side? (the console daemon or the

In any case, I have to admit it hasn't bitten us in practice when
using gdb; either gdb is smart enough to handle this on its own or I'm
missing something. However, supporting --noecho is still nicer from an
aesthetic point of view: compare a console session with and without
--noecho and using telnet on the remote side - without it you get
everything you write echo'd back at you.


Xen-devel mailing list