From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olaf Hering <olaf@aepfle.de>
Subject: Re: [PATCH] libxl: initialize vfb defbools in
 libxlMakeVfb
Date: Wed, 6 May 2015 10:24:54 +0200
Message-ID: <20150506082454.GB10182__1317.07192999801$1430901197$gmane$org@aepfle.de>
References: <1429291171-23640-1-git-send-email-olaf@aepfle.de>
	<20150417175928.GA2516@aepfle.de> <553165B7.8000204@suse.com>
	<1430487940.15640.32.camel@citrix.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
Content-Disposition: inline
In-Reply-To: <1430487940.15640.32.camel@citrix.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Ian Campbell <ian.campbell@citrix.com>
Cc: libvir-list@redhat.com, Jim Fehlig <jfehlig@suse.com>, xen-devel@lists.xen.org
List-Id: xen-devel@lists.xenproject.org

On Fri, May 01, Ian Campbell wrote:

> Olaf, please can you use gdb to capture the stack trace so we can fix
> this (and the other issue) properly in libxl instead of just hacking
> around it in libvirt (which might also be appropriate for compat with
> old libxl but shouldn't be done without also fixing libxl IMHO).

The code flow was essentially like this:

libxl_device_vfb_init(libxl);
switch(libvirt->type) {
  case SDL:
    libxl_defbool_set(libxl->sdl.enable, 1);
    break;
  case VNC:
    libxl_defbool_set(libxl->vnc.enable, 1);
    break;
}

if (libvirt->os.type == HVM) {
  if (libxl_defbool_val(libxl->vnc.enable)) {
    /* do VNC things */
  } else if (libxl_defbool_val(libxl->sdl.enable)) {
    /* do SDL things */
    if (libxl_defbool_val(libxl->opengl.enable))
      /* do openGL things */
  }
}


The first crash was because I had SDL enabled, and the SDL case did not
initialize the defbool for VNC. Once it did the next crash was the
openGL part which was not initialized either.

I see nothing wrong with libxl in such usage.

Olaf