From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38333) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SC8uh-0004Lh-LQ for qemu-devel@nongnu.org; Mon, 26 Mar 2012 08:20:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SC8ub-0000Ex-AN for qemu-devel@nongnu.org; Mon, 26 Mar 2012 08:20:43 -0400 Received: from goliath.siemens.de ([192.35.17.28]:27235) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SC8ub-0000EH-0g for qemu-devel@nongnu.org; Mon, 26 Mar 2012 08:20:37 -0400 Message-ID: <4F705F08.4010002@siemens.com> Date: Mon, 26 Mar 2012 14:20:24 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <1332727608-26523-1-git-send-email-liwp@linux.vnet.ibm.com> In-Reply-To: <1332727608-26523-1-git-send-email-liwp@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/6] refactor PC machine, i440fx and piix3 to take advantage of QOM List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wanpeng Li Cc: Anthony Liguori , Gavin Shan , qemu-devel@nongnu.org, Isaku Yamahata , Avi Kivity , Paolo Bonzini On 2012-03-26 04:06, Wanpeng Li wrote: > From: Anthony Liguori > > > This series aggressively refactors the PC machine initialization to be more > modelled and less ad-hoc. The highlights of this series are: > > 1) Things like -m and -bios-name are now device model properties > > 2) The i440fx and piix3 are now modelled in a thorough fashion > > 3) Most of the chipset features of the piix3 are modelled through composition > > 4) i440fx_init is trivialized to creating devices and setting properties > > 5) convert MemoryRegion to QOM > > 6) convert PCI host bridge to QOM > > The point (4) is the most important one. As we refactor in this fashion, > we should quickly get to the point where machine->init disappears completely in > favor of just creating a handful of devices. > > The two stage initialization of QOM is important here. instance_init() is when > composed devices are created which means that after you've created a device, all > of its children are visible in the device model. This lets you set properties > of the parent and its children. > > realize() (which is still called DeviceState::init today) will be called right > before the guest starts up for the first time. While I see the value of the overall direction, I still disagree on making internal data structures of HPET, RTC and 8254 publicly available. That's a wrong step back. I'm sure there are smarter solutions, alse as there were some proposals back then in the original thread. I'm also sure we will have to refactor the merge significantly again for the introduction of additional chipsets and PC boards. But unless those requirements can already be specified (Isaku?), that might be unavoidable. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux