From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:54562) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qy995-0008IS-2b for qemu-devel@nongnu.org; Mon, 29 Aug 2011 17:13:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Qy993-0001I5-Mj for qemu-devel@nongnu.org; Mon, 29 Aug 2011 17:13:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62000) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qy993-0001Hk-DT for qemu-devel@nongnu.org; Mon, 29 Aug 2011 17:13:25 -0400 Message-ID: <4E5C00F0.9070103@redhat.com> Date: Tue, 30 Aug 2011 00:13:20 +0300 From: Avi Kivity MIME-Version: 1.0 References: <4E58FC3F.6080809@web.de> <4E5BE7C5.60705@us.ibm.com> <4E5BFF51.9010503@web.de> In-Reply-To: <4E5BFF51.9010503@web.de> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] pc: Clean up PIC-to-APIC IRQ path List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Lucas Meneghel Rodrigues , Anthony Liguori , Marcelo Tosatti , Gerd Hoffmann , qemu-devel On 08/30/2011 12:06 AM, Jan Kiszka wrote: > > > > Does this need to be save/restored for migration? > > Nope, but we need some other measure. I thought to remember the pic was > refreshing this after load, but I do not find any traces of this now. We > likely need a post_load handler in the i8259 that re-asserts the IRQ as > required. > We need some kind of two phase restore. In the first phase all state is restored; since some of that state drivers outputs that are input to other devices, they may experience an edge, and we need to supress that. In the second phase edge detection is unsupressed and the device goes live. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.