From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=44453 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OnT2E-0004I6-Hq for qemu-devel@nongnu.org; Mon, 23 Aug 2010 05:09:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OnT2D-0002zR-3B for qemu-devel@nongnu.org; Mon, 23 Aug 2010 05:09:42 -0400 Received: from thoth.sbs.de ([192.35.17.2]:22840) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OnT2C-0002xG-EL for qemu-devel@nongnu.org; Mon, 23 Aug 2010 05:09:41 -0400 Message-ID: <4C723ABE.4080801@siemens.com> Date: Mon, 23 Aug 2010 11:09:18 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <4C6D86F9.3010602@codemonkey.ws> <4C6D98E7.9020109@codemonkey.ws> <4C70EFC9.2050404@redhat.com> <4C7171EB.7090301@codemonkey.ws> <4C717E05.50609@redhat.com> <4C718296.8030405@codemonkey.ws> <4C71898E.9090105@redhat.com> <4C71913C.5090300@codemonkey.ws> <4C720BF1.6090305@redhat.com> In-Reply-To: <4C720BF1.6090305@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH v2 0/7] APIC/IOAPIC cleanup List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: Blue Swirl , "Liu >> \"Liu, Jinsong\"" , qemu-devel , Paul Brook Avi Kivity wrote: > On 08/23/2010 12:06 AM, Anthony Liguori wrote: >> On 08/22/2010 03:33 PM, Avi Kivity wrote: >>> On 08/22/2010 11:03 PM, Anthony Liguori wrote: >>>> On 08/22/2010 02:44 PM, Avi Kivity wrote: >>>>>> No more MI diamond and all devices have DeviceStates. >>>>>> Coincidentally, it matches more closely how hardware works.. >>>>>> >>>>> >>>>> >>>>> Well, I agree, but I honestly lost the context. How does this >>>>> relate to the APIC and cpu hotplug? >>>> >>>> My original assertion was that the local APIC is not a DeviceState, >>>> but rather it's a CPU feature. >>>> >>>> If you look at some of the magic that apic.c has to do in the IO >>>> callbacks, it should be clear that it's special. >>> >>> It's special in that it is connected to a cpu core. So's the RTL8139 >>> device, on one hand connected to a PCI bus, on the other hand >>> connected to a PHY (netdev in qemu). >>> >>>> In the not too distant future, I'd like to move apic.c to >>>> target-i386. There should be no need to explicitly instantiate it >>>> when you instantiate a CPU. >>> >>> But then there's a need explicitly not to instantiate it when using >>> -isapc. >> >> No. isapc has nothing to do with whether a CPU has a local APIC. >> >> You don't instantiate the local APIC if you create a 486 CPU. If you >> create an isapc with a pentium processor, it's going to have a local >> APIC although it's irrelevant as it's fully compatible with the 486. >> > > Okay, okay. "But then there's a need explicitly not to instantiate it > when modelling a 486 or lower". ...plus the need to instantiate it (as a dedicated device) when modeling 486 SMP. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux