From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49508) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bxEfP-00036D-FC for qemu-devel@nongnu.org; Thu, 20 Oct 2016 10:50:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bxEfM-0004lc-Ev for qemu-devel@nongnu.org; Thu, 20 Oct 2016 10:49:59 -0400 Received: from mail-qk0-x231.google.com ([2607:f8b0:400d:c09::231]:36156) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1bxEfM-0004lV-9T for qemu-devel@nongnu.org; Thu, 20 Oct 2016 10:49:56 -0400 Received: by mail-qk0-x231.google.com with SMTP id o68so98590022qkf.3 for ; Thu, 20 Oct 2016 07:49:55 -0700 (PDT) Date: Thu, 20 Oct 2016 10:49:54 -0400 From: Kevin O'Connor Message-ID: <20161020144954.GA27352@morn.lan> References: <1476878743-144953-1-git-send-email-imammedo@redhat.com> <1476878743-144953-12-git-send-email-imammedo@redhat.com> <20161019131546.GL5057@thinpad.lan.raisama.net> <20161019171838.4a9343f6@nial.brq.redhat.com> <20161019182929.GR5057@thinpad.lan.raisama.net> <20161020132734.33060b44@nial.brq.redhat.com> <20161020122733.GT5057@thinpad.lan.raisama.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161020122733.GT5057@thinpad.lan.raisama.net> Subject: Re: [Qemu-devel] [PATCH v4 11/13] pc: add 'etc/boot-cpus' fw_cfg file for machine with more than 255 CPUs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Igor Mammedov , qemu-devel@nongnu.org, kraxel@redhat.com, liuxiaojian6@huawei.com, mst@redhat.com, rkrcmar@redhat.com, peterx@redhat.com, pbonzini@redhat.com, lersek@redhat.com, chao.gao@intel.com On Thu, Oct 20, 2016 at 10:27:33AM -0200, Eduardo Habkost wrote: > (Why does SeaBIOS need to start the other CPUs, anyway, except > for building the APIC ID list for the ACPI tables?) SeaBIOS only starts the other CPUs when running on QEMU (it does not on coreboot). The main reason is to initialize the MTRR registers on those CPUs. It's also used to create the apic id list which is used during the generation of the mptable, and during the generation of the ACPI tables if an old QEMU machine type is running that doesn't pass ACPI tables to SeaBIOS. -Kevin