From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [Qemu-devel] Anyone seeing huge slowdown launching qemu with Linux 2.6.35? Date: Wed, 04 Aug 2010 07:59:18 -0500 Message-ID: <4C596426.40702@codemonkey.ws> References: <4C584B66.5070404@redhat.com> <4C5854F1.3000905@codemonkey.ws> <4C5858B2.9090801@redhat.com> <4C585F5B.5070502@codemonkey.ws> <4C58635B.7020407@redhat.com> <20100803190525.GB16570@redhat.com> <4C586AB9.5040302@codemonkey.ws> <4C586CF9.7030206@redhat.com> <20100803220628.GC28523@amd.home.annexia.org> <4C59009B.1050500@redhat.com> <20100804092428.GD28523@amd.home.annexia.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Gleb Natapov , qemu-devel@nongnu.org, kvm@vger.kernel.org To: "Richard W.M. Jones" Return-path: Received: from mail-qy0-f174.google.com ([209.85.216.174]:39574 "EHLO mail-qy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932455Ab0HDM7W (ORCPT ); Wed, 4 Aug 2010 08:59:22 -0400 Received: by qyk7 with SMTP id 7so1140418qyk.19 for ; Wed, 04 Aug 2010 05:59:21 -0700 (PDT) In-Reply-To: <20100804092428.GD28523@amd.home.annexia.org> Sender: kvm-owner@vger.kernel.org List-ID: On 08/04/2010 04:24 AM, Richard W.M. Jones wrote: > On Wed, Aug 04, 2010 at 08:54:35AM +0300, Avi Kivity wrote: > >> On 08/04/2010 01:06 AM, Richard W.M. Jones wrote: >> >>> On Tue, Aug 03, 2010 at 10:24:41PM +0300, Avi Kivity wrote: >>> >>>> Why do we need to transfer roms? These are devices on the memory >>>> bus or pci bus, it just needs to be there at the right address. >>>> Boot splash should just be another rom as it would be on a real >>>> system. >>>> >>> Just like the initrd? >>> >> There isn't enough address space for a 100MB initrd in ROM. >> > Because of limits of the original PC, sure, where you had to fit > everything in 0xa0000-0xfffff or whatever it was. > > But this isn't a real PC. > > You can map the read-only memory anywhere you want. > It's not that simple. Option roms are initialized in 16-bit mode so the physical address space is limited. The address mappings have very well defined semantics. Regards, Anthony Liguori > Rich. > > From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=41936 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OgdZ5-0001nv-9B for qemu-devel@nongnu.org; Wed, 04 Aug 2010 08:59:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OgdZ3-0000bL-ST for qemu-devel@nongnu.org; Wed, 04 Aug 2010 08:59:23 -0400 Received: from mail-qw0-f45.google.com ([209.85.216.45]:52785) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OgdZ3-0000bE-PV for qemu-devel@nongnu.org; Wed, 04 Aug 2010 08:59:21 -0400 Received: by qwf6 with SMTP id 6so900756qwf.4 for ; Wed, 04 Aug 2010 05:59:21 -0700 (PDT) Message-ID: <4C596426.40702@codemonkey.ws> Date: Wed, 04 Aug 2010 07:59:18 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] Anyone seeing huge slowdown launching qemu with Linux 2.6.35? References: <4C584B66.5070404@redhat.com> <4C5854F1.3000905@codemonkey.ws> <4C5858B2.9090801@redhat.com> <4C585F5B.5070502@codemonkey.ws> <4C58635B.7020407@redhat.com> <20100803190525.GB16570@redhat.com> <4C586AB9.5040302@codemonkey.ws> <4C586CF9.7030206@redhat.com> <20100803220628.GC28523@amd.home.annexia.org> <4C59009B.1050500@redhat.com> <20100804092428.GD28523@amd.home.annexia.org> In-Reply-To: <20100804092428.GD28523@amd.home.annexia.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Richard W.M. Jones" Cc: kvm@vger.kernel.org, Avi Kivity , Gleb Natapov , qemu-devel@nongnu.org On 08/04/2010 04:24 AM, Richard W.M. Jones wrote: > On Wed, Aug 04, 2010 at 08:54:35AM +0300, Avi Kivity wrote: > >> On 08/04/2010 01:06 AM, Richard W.M. Jones wrote: >> >>> On Tue, Aug 03, 2010 at 10:24:41PM +0300, Avi Kivity wrote: >>> >>>> Why do we need to transfer roms? These are devices on the memory >>>> bus or pci bus, it just needs to be there at the right address. >>>> Boot splash should just be another rom as it would be on a real >>>> system. >>>> >>> Just like the initrd? >>> >> There isn't enough address space for a 100MB initrd in ROM. >> > Because of limits of the original PC, sure, where you had to fit > everything in 0xa0000-0xfffff or whatever it was. > > But this isn't a real PC. > > You can map the read-only memory anywhere you want. > It's not that simple. Option roms are initialized in 16-bit mode so the physical address space is limited. The address mappings have very well defined semantics. Regards, Anthony Liguori > Rich. > >