From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.33) id 1BogEE-0003EA-FY for qemu-devel@nongnu.org; Sun, 25 Jul 2004 06:27:38 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.33) id 1BogEC-0003Dy-Nl for qemu-devel@nongnu.org; Sun, 25 Jul 2004 06:27:38 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1BogEC-0003Dv-6D for qemu-devel@nongnu.org; Sun, 25 Jul 2004 06:27:36 -0400 Received: from [151.189.21.47] (helo=mail-in-07.arcor-online.net) by monty-python.gnu.org with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.34) id 1BogB8-0001PL-Ru for qemu-devel@nongnu.org; Sun, 25 Jul 2004 06:24:27 -0400 Received: from halef.NotaMusica.com (dsl-082-082-143-071.arcor-ip.net [82.82.143.71]) by mail-in-07.arcor-online.net (Postfix) with ESMTP id 56B1A10F17E for ; Sun, 25 Jul 2004 12:24:24 +0200 (CEST) Received: from halef.NotaMusica.com (localhost [127.0.0.1]) by halef.NotaMusica.com (8.12.3/8.12.3/Debian-6.6) with ESMTP id i6PAOK02001572 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Sun, 25 Jul 2004 12:24:20 +0200 Received: from localhost (jmartin@localhost) by halef.NotaMusica.com (8.12.3/8.12.3/Debian-6.6) with ESMTP id i6PAOHEo001567 for ; Sun, 25 Jul 2004 12:24:20 +0200 Date: Sun, 25 Jul 2004 12:24:16 +0200 (CEST) From: Johannes Martin Subject: Re: [Qemu-devel] qemu-fast kernel patch question In-Reply-To: <200407251401.09826.a_mulyadi@softhome.net> Message-ID: References: <410280F2.4020809@optusnet.com.au> <200407250737.44458.a_mulyadi@softhome.net> <4103174F.5040907@optusnet.com.au> <200407251401.09826.a_mulyadi@softhome.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 Hi, On Sun, 25 Jul 2004, Mulyadi Santosa wrote: > Do you mean: > 1. applying qemu-fast patch to Win98 guest? --> Not a chance :-) > 2. running qemu-fast on top of Win98 host? Well, I haven't tried it > personally. But, if you can run qemu-fast on Win98 host, I doubt if qemu-fast > can do direct MMU access. The reason is: to do direct MMU access, the > developers need to know to request that into host kernel. On Linux or other > open source kernel, we can find it out, but on closed kernel, this would be > difficult..... > > The conclusion: just run the usual "qemu" on top of Win98 host Here's a quote from qemu-tech.html: --- 2.10 MMU emulation For system emulation, QEMU uses the mmap() system call to emulate the target CPU MMU. It works as long the emulated OS does not use an area reserved by the host OS (such as the area above 0xc0000000 on x86 Linux). --- As far as I understand this, the qemu kernel patch makes the guest kernel use a different reserved area than the linux host. So it shouldn't matter which kernel I apply the patch to, right? If I patch the (linux) host kernel, I should be able to boot any unpatched (linux) guest kernel, if I don't patch the (linux) host kernel, I have to patch my (linux) guest kernels. Or do we need a patch-aware qemy-fast to run on a patched host? Assuming that OS XYZ does not use the area around 0xc0000000, it should work inside qemu-fast, right? And if it does use that area, it should work inside qemu-fast on a patched host? Maybe one of the wizards could clarify this... Thanks Johannes