From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1I4CzG-0007CE-BJ for qemu-devel@nongnu.org; Fri, 29 Jun 2007 05:41:58 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1I4CzF-0007BK-4D for qemu-devel@nongnu.org; Fri, 29 Jun 2007 05:41:57 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1I4CzD-0007B1-9K for qemu-devel@nongnu.org; Fri, 29 Jun 2007 05:41:56 -0400 Received: from ug-out-1314.google.com ([66.249.92.168]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1I4CzC-0002gW-RJ for qemu-devel@nongnu.org; Fri, 29 Jun 2007 05:41:55 -0400 Received: by ug-out-1314.google.com with SMTP id m2so505470uge for ; Fri, 29 Jun 2007 02:41:53 -0700 (PDT) Message-ID: Date: Fri, 29 Jun 2007 12:41:53 +0300 From: "Blue Swirl" MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline Subject: [Qemu-devel] 4G address space remapping on 64-bit host 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 Hi, I had an idea of mapping the full 32-bit target virtual address space to a 4GB area on 64-bit hosts. Then the loads and stores to normal RAM (except page tables, code_mem_write etc) could be made much faster, falling back to softmmu for other pages. The idea has come up before, for example in this Fabrice's message: http://article.gmane.org/gmane.comp.emulators.qemu/685 But I'm not sure if this would be worth the effort, the speedup would depend on the frequency of the loads/stores and also translation time vs. translated code execution times. Does anyone have good statistics on those?