From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1Kstis-0003aM-SY for qemu-devel@nongnu.org; Thu, 23 Oct 2008 02:31:06 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1Kstiq-0003XX-Gl for qemu-devel@nongnu.org; Thu, 23 Oct 2008 02:31:05 -0400 Received: from [199.232.76.173] (port=41964 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Kstiq-0003XL-9U for qemu-devel@nongnu.org; Thu, 23 Oct 2008 02:31:04 -0400 Received: from wf-out-1314.google.com ([209.85.200.168]:24738) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1Kstiq-0008JY-2e for qemu-devel@nongnu.org; Thu, 23 Oct 2008 02:31:04 -0400 Received: by wf-out-1314.google.com with SMTP id 27so195757wfd.4 for ; Wed, 22 Oct 2008 23:31:02 -0700 (PDT) Message-ID: <761ea48b0810222331g2e56f4e0ocde6229ae975d5ef@mail.gmail.com> Date: Thu, 23 Oct 2008 08:31:02 +0200 From: "Laurent Desnogues" Subject: Re: [Qemu-devel] [PATCH] [resubmit] Allocate translation buffer before guest RAM, in case guest RAM is too large on 64 bit hosts In-Reply-To: <20081022221051.GA14534@saturn.kn-bremen.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20081022221051.GA14534@saturn.kn-bremen.de> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org On Thu, Oct 23, 2008 at 12:10 AM, Juergen Lock wrote: > > Further explanation as requested: cpu_exec_init_all() below allocates > code_gen_buffer which needs to be in the lower 4G (actually 2G I guess) > because it uses 32 bit branch offsets. Allocate this first so that the > guest RAM allocation can't get in the way i.e. block the lower vm when > doing something like -m 4096 on systems that allocate from low addresses > by default. > > I hope this is more clear now? :) What about including a shorter version of that explanation as a comment in your patch ? :) Laurent