From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1GuVI1-0004to-27 for qemu-devel@nongnu.org; Wed, 13 Dec 2006 09:40:57 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1GuVHy-0004qz-41 for qemu-devel@nongnu.org; Wed, 13 Dec 2006 09:40:56 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1GuVHx-0004qU-SI for qemu-devel@nongnu.org; Wed, 13 Dec 2006 09:40:53 -0500 Received: from [209.198.128.91] (helo=smtp.prismnet.com) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1GuVHx-0001Cm-R5 for qemu-devel@nongnu.org; Wed, 13 Dec 2006 09:40:54 -0500 Received: from [10.0.1.201] (206-224-83-140-dialup.io.com [206.224.83.140]) by smtp.prismnet.com (8.13.4/8.13.4) with ESMTP id kBDEeRuW034591 for ; Wed, 13 Dec 2006 08:40:28 -0600 (CST) (envelope-from tim@io.com) Mime-Version: 1.0 (Apple Message framework v624) In-Reply-To: <56d259a00612130526u214987e6kfbe926d8bba018f0@mail.gmail.com> References: <10541fa50612130009s798a1587n4a3d2b8b51baa334@mail.gmail.com> <56d259a00612130526u214987e6kfbe926d8bba018f0@mail.gmail.com> Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <9cfca86c3aa677137448f7a0a85e3ccb@io.com> Content-Transfer-Encoding: 7bit From: Tim Olson Date: Wed, 13 Dec 2006 08:40:29 -0600 Subject: [Qemu-devel] qemu-system-* using mmap? 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 I am using qemu 0.8.2 built from source. In the qemu technical documentation for features under full system emulation, it says: "QEMU can either use a full software MMU for maximum portability or use the host system call mmap() to simulate the target MMU." However, I cannot find a way to build a full system simulator which does not define SOFTMMU -- in fact, the configure parameters "--disable-system" and "--enable-system" directly control the softmmu switch. There are some mmap() calls in the kqemu code, but to use that requires full kqemu support code in the kernel. I think there is a big performance hit using the software mmu, as each target load or store instruction is expanded into 20-30 host instructions to perform the translation. Is there a way to build the qemu-system-* emulators using the mmap() feature mentioned in the documentation? -- Tim Olson