From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1GuWc2-0006oa-HR for qemu-devel@nongnu.org; Wed, 13 Dec 2006 11:05:42 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1GuWc2-0006oH-3Z for qemu-devel@nongnu.org; Wed, 13 Dec 2006 11:05:42 -0500 Received: from [69.69.215.43] (helo=mail.premiumoperatingsystems.net) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA:32) (Exim 4.52) id 1GuWc1-0006XZ-KN for qemu-devel@nongnu.org; Wed, 13 Dec 2006 11:05:41 -0500 Received: from [192.168.2.30] (nc-71-48-24-78.dhcp.embarqhsd.net [71.48.24.78]) (authenticated bits=0) by mail.premiumoperatingsystems.net (8.12.11/8.12.11) with ESMTP id kBDF4sG6003941 for ; Wed, 13 Dec 2006 10:04:54 -0500 Message-ID: <45802498.6020808@tidetamerboatlifts.com> Date: Wed, 13 Dec 2006 11:04:40 -0500 From: Joseph Miller MIME-Version: 1.0 Subject: Re: [Qemu-devel] qemu-system-* using mmap? References: <10541fa50612130009s798a1587n4a3d2b8b51baa334@mail.gmail.com> <56d259a00612130526u214987e6kfbe926d8bba018f0@mail.gmail.com> <9cfca86c3aa677137448f7a0a85e3ccb@io.com> In-Reply-To: <9cfca86c3aa677137448f7a0a85e3ccb@io.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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 Tim Olson wrote: > 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 > > > > _______________________________________________ > Qemu-devel mailing list > Qemu-devel@nongnu.org > http://lists.nongnu.org/mailman/listinfo/qemu-devel Can someone elaborate on this a little? What is the difference between the SOFTMMU and the mmap()? Should I be using the --enable-system or the --disable-system for win32 guest on i386 debian host? Can someone give a little more insight on this technicality? -Joseph