From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1M1l9E-0005cn-Kr for qemu-devel@nongnu.org; Wed, 06 May 2009 13:43:12 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1M1l99-0005ag-Jz for qemu-devel@nongnu.org; Wed, 06 May 2009 13:43:12 -0400 Received: from [199.232.76.173] (port=53772 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1M1l99-0005ab-GF for qemu-devel@nongnu.org; Wed, 06 May 2009 13:43:07 -0400 Received: from mail-bw0-f175.google.com ([209.85.218.175]:48388) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1M1l99-00032X-0U for qemu-devel@nongnu.org; Wed, 06 May 2009 13:43:07 -0400 Received: by bwz23 with SMTP id 23so283357bwz.34 for ; Wed, 06 May 2009 10:43:05 -0700 (PDT) From: "Stanislav" References: <1241621382-21577-1-git-send-email-glommer@redhat.com> <1241621382-21577-2-git-send-email-glommer@redhat.com> <1241621382-21577-3-git-send-email-glommer@redhat.com> <4A01AF78.7050102@siemens.com> <20090506155141.GE26401@poweredge.glommer> <000001c9ce70$3416d3a0$9c447ae0$@com> <20090506174136.GG26401@poweredge.glommer> In-Reply-To: <20090506174136.GG26401@poweredge.glommer> Subject: RE: [Qemu-devel] Re: [PATCH 2/4] move CPUID_APIC flag to where it belongs Date: Wed, 6 May 2009 20:43:09 +0300 Message-ID: <000101c9ce72$201b6670$60523350$@com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Language: en-us List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: 'Glauber Costa' Cc: 'Jan Kiszka' , aliguori@us.ibm.com, qemu-devel@nongnu.org Local apic and i/o apic are not really related. Local apic is actually a cpu feature, not optional external peripheral. I/O apic is external hardware on board and if you don't have it - you can't program your interrupts that much. I am not telling if a patch is wrong/better than it was before - just want to point out how it really works. Stanislav -----Original Message----- From: Glauber Costa [mailto:glommer@redhat.com] Sent: Wednesday, May 06, 2009 8:42 PM To: Stanislav Cc: 'Jan Kiszka'; aliguori@us.ibm.com; qemu-devel@nongnu.org Subject: Re: [Qemu-devel] Re: [PATCH 2/4] move CPUID_APIC flag to where it belongs On Wed, May 06, 2009 at 08:29:23PM +0300, Stanislav wrote: > If OS boot fine its more luck. The flag indicates presence of local apic, > not "if it is supported". > For example when lapic is globally disabled (i.e. not present) CPUID flag is > cleared off as well. > But CPU is still supports lapic, after reset it will be back. What if we take out a cpu that supports lapic, and is connected to an apic system, and connects it to a board that has no apic? Also, note that in the old code, it was set regardless of the existance of an APIC anyway. The only dependancy was on smp_cpus > 1.