From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: hvm crash on hypercall event channel Date: Wed, 11 Apr 2012 13:44:54 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Daniel Castro , Ian Campbell Cc: "xen-devel@lists.xensource.com" , "Tim (Xen.org)" List-Id: xen-devel@lists.xenproject.org On 11/04/2012 13:24, "Daniel Castro" wrote: >> It's looking likely that you'll have to go to 32 bit mode to do all of >> the actual I/O associated with the PV devices. That ought to simplify a >> bunch of stuff WRT handling the rings etc too. > > What are my choices? > 1. Add support for 16bit hypercalls on Xen. > 2. Jump to 32 bit I think this is best. Compile the 32-bit drivers as 32-bit code, then use stubs to transfer between 16-bit and 32-bit execution modes at run time. Our old rombios has code you could borrow for this, if seabios doesn't already have such functionality. -- Keir > 3. make a 16bit "special" hypercall on SeaBIOS > 4. Any other choice? > > Thanks to all the comments.