From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=51461 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OnPvV-0002Ie-Pi for qemu-devel@nongnu.org; Mon, 23 Aug 2010 01:50:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OnPup-0002Y8-5K for qemu-devel@nongnu.org; Mon, 23 Aug 2010 01:49:52 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50809) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OnPuo-0002Y0-TK for qemu-devel@nongnu.org; Mon, 23 Aug 2010 01:49:51 -0400 Message-ID: <4C720BF1.6090305@redhat.com> Date: Mon, 23 Aug 2010 08:49:37 +0300 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH v2 0/7] APIC/IOAPIC cleanup 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> In-Reply-To: <4C71913C.5090300@codemonkey.ws> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Blue Swirl , "Liu >> \"Liu, Jinsong\"" , qemu-devel , Paul Brook 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". -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.