From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LP2Lc-0004fj-AP for qemu-devel@nongnu.org; Mon, 19 Jan 2009 17:11:56 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LP2LZ-0004fT-NT for qemu-devel@nongnu.org; Mon, 19 Jan 2009 17:11:54 -0500 Received: from [199.232.76.173] (port=37276 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LP2LZ-0004fQ-Hi for qemu-devel@nongnu.org; Mon, 19 Jan 2009 17:11:53 -0500 Received: from mail-qy0-f20.google.com ([209.85.221.20]:65147) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LP2LZ-000792-EJ for qemu-devel@nongnu.org; Mon, 19 Jan 2009 17:11:53 -0500 Received: by qyk13 with SMTP id 13so4291756qyk.10 for ; Mon, 19 Jan 2009 14:11:52 -0800 (PST) Message-ID: <4974FA9B.5000900@codemonkey.ws> Date: Mon, 19 Jan 2009 16:11:39 -0600 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [6352] Fix character devices after DisplayState refactoring References: <49746372.8070703@eu.citrix.com> In-Reply-To: <49746372.8070703@eu.citrix.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Stefano Stabellini wrote: > Anthony Liguori wrote: > > >> Revision: 6352 >> http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=6352 >> Author: aliguori >> Date: 2009-01-16 20:23:27 +0000 (Fri, 16 Jan 2009) >> >> Log Message: >> ----------- >> Fix character devices after DisplayState refactoring >> >> The DisplayState refactoring changed the machine init function to create a >> DisplayState for each VGA device instead of being passed an existing >> DisplayState. This change is critical to enable multiple graphics device >> support. >> >> Unfortunately, the serial/parallel/console code is structured today to run >> before machine init to fill out the CharDriverState table which the machine >> init function uses to determine whether to create the required devices. >> >> Since a 'vc' is a type of CharDriverState, the CharDriverState code requires >> that a DisplayState exist before it runs creating a circular dependency. >> >> To fix this, this splits the creation of the initial CharDriverState from >> the initialization of the text console. We can then in a second step associate >> a DisplayState with all TextConsoles. This allows us to create the >> CharDriverState's first, machine init, then associate the TextConsoles with >> a DisplayState. >> >> This code screams for more cleanup. >> >> > > I am sorry for this. > No worries. What I meant about more cleanup was that this patch series demonstrated a fundamental flaw in the CharDriverState abstraction. That is, we really ought to separate the creation of a CharDriverState front-end from the creation of the back-end. We should then attach a front-end to a back-end. This would make it easy to dynamically change the back-end of any given CharDriverState which is something I've liked to see for a while now. Regards, Anthony Liguori > While I was testing the patch series I was expecting many rendering > issues or console switching issues: once I saw that both the serial and > parallel port consoles were present I didn't check they were actually > working. > > > >