From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dale Farnsworth Subject: Re: KVM on MIPS? Date: Fri, 26 Mar 2010 12:59:28 -0700 Message-ID: <20100326195928.GA6472@farnsworth.org> References: <20100325165442.GA21343@farnsworth.org> <4BABCFEB.9050409@redhat.com> <4475EEC9-3582-4CDA-A740-9C4DAAB3738C@suse.de> <20100326161619.GA31195@farnsworth.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Avi Kivity To: Alexander Graf , kvm@vger.kernel.org Return-path: Received: from xyzzy.farnsworth.org ([65.39.95.219]:53342 "EHLO xyzzy.farnsworth.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752320Ab0CZT7i (ORCPT ); Fri, 26 Mar 2010 15:59:38 -0400 Content-Disposition: inline In-Reply-To: <20100326161619.GA31195@farnsworth.org> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, Mar 26, 2010 at 09:16:19AM -0700, Dale Farnsworth wrote: > On Thu, Mar 25, 2010 at 11:32:57PM +0100, Alexander Graf wrote: > > > > Am 25.03.2010 um 22:04 schrieb Avi Kivity : > > > >> On 03/25/2010 06:54 PM, Dale Farnsworth wrote: > >>> I'm beginning to look at implementing KVM on MIPS. I've tried to > >>> search > >>> for any work-in-progress on this but haven't found much at all. > >> > >>> If you know of anyone who is working on this or of pitfalls I should > >>> consider before jumping in, please let me know. > >>> > >> > >> Is the instruction set virtualizable? > > > > FWIW it's not. Kernel mode is used based on an address offset of the IP. > > Since you'd want to have your guest running in user mode, you're pretty > > much lost there. > > I guess that would qualify as a pitfall. Thanks Avi and Alex. After thinking about this some more, I think this means we can't run an unmodified guest. It should be possible to build the guest kernel to run in supervisor or user mode/address space. I'm new to MIPS, so I'm still looking for other challenges in virtualizing the instruction set. -Dale