From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MDdUM-0005EJ-FO for qemu-devel@nongnu.org; Mon, 08 Jun 2009 07:58:06 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MDdUH-00058b-Kp for qemu-devel@nongnu.org; Mon, 08 Jun 2009 07:58:05 -0400 Received: from [199.232.76.173] (port=33709 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MDdUH-00058I-EL for qemu-devel@nongnu.org; Mon, 08 Jun 2009 07:58:01 -0400 Received: from mail2.shareable.org ([80.68.89.115]:35071) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MDdUH-0002lE-17 for qemu-devel@nongnu.org; Mon, 08 Jun 2009 07:58:01 -0400 Date: Mon, 8 Jun 2009 12:57:55 +0100 From: Jamie Lokier Subject: Re: [Qemu-devel] POLL: Why do you use kqemu? Message-ID: <20090608115755.GD25684@shareable.org> References: <4A26F1E3.1040509@codemonkey.ws> <4A27FC69.9070501@mayc.ru> <20090605201415.GA22847@csclub.uwaterloo.ca> <20090608001312.GE15426@shareable.org> <4A2CA8C2.2080004@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A2CA8C2.2080004@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: Lennart Sorensen , "qemu-devel@nongnu.org" , Anton D Kachalov Avi Kivity wrote: > Jamie Lokier wrote: > >Johannes Schindelin wrote: > > > >>>Yeah I don't either. I actually thought kvm had replaced it effectively. > >>> > >>You might have realized from the available answers that not everybody is > >>lucky enough to be able to afford 2 week old hardware, and therefore not > >>everybody is able to use kvm. > >> > > > >Plus kvm's not suitable for some guests. I'm thinking old Windows > >guests with 16-bit kernel code here. > > > > kvm on amd will run these perfectly. So the "Guest Support Status" prominently on the front page of linux-kvm.org is wrong for current versions? It specifically mentions AMD hosts. (I notice AMD KVM != Intel KVM hasn't factored into this discussion yet...) Guest KVM tested Host CPU/bits Result ---------------------------------------------------------------- Windows 98SE kvm-63 Intel 32 Fails Windows 98SE kvm-80, 2.6.27.7 AMD 64 no way Windows 95 kvm-44, 2.6.23-rc8 AMD 64, 32 no way > >It has come up before that kvm will eventually support 16-bit code > >better, although I got the impression that it would never support full > >16-bit virtualisation accurately, so e.g. Windows 95 will not run on > >it, nor some other partially 16-bit OSes. Possibly not even very old > >versions of Linux, I'm not sure. > > > >Don't ask me _why_ I want to run them. :-) > > > >Just a data point that it's not just about the host hardware, and as > >far as I know kqemu can accelerate them. > > > > It falls back to qemu for 16-bit code. I was under the impression it was planned to remove TCG support when using KVM. If not, fine, it's ok for 16-bit code to run in TCG and probably better than vm86 or the in-kernel interpreter. -- Jamie