Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753001Ab3HAUBC (ORCPT ); Thu, 1 Aug 2013 16:01:02 -0400 Received: from plane.gmane.org ([80.91.229.3]:43060 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751362Ab3HAUBA (ORCPT ); Thu, 1 Aug 2013 16:01:00 -0400 X-Injected-Via-Gmane: http://gmane.org/ To: linux-kernel@vger.kernel.org From: Alex Elsayed Subject: Re: [QUERY] lguest64 Date: Thu, 01 Aug 2013 13:04:22 +0000 Message-ID: References: <51E97779.3020103@zytor.com> <51E989A0.8050103@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7Bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: c-24-17-197-101.hsd1.wa.comcast.net User-Agent: KNode/4.10.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1738 Lines: 37 Ramkumar Ramachandra wrote: > H. Peter Anvin wrote: >> UML, lguest and Xen were done before the x86 architecture supported >> hardware virtualization. > > [...] > >> but on KVM-enabled hardware KVM seems >> like the better option (and is indeed what libguestfs uses.) > > While we're still on the topic, I'd like a few clarifications. From > your reply, I got the impression that KVM the only mechanism for > non-pvops virtualization. This seems quite contrary to what I read on > lwn about ARM virtualization [1]. In short, ARM provides a "hypervisor > mode", and the article says > > "the virtualization model provided by ARM fits the Xen > hypervisor-based virtualization better than KVM's kernel-based model" > > The Xen people call this "ARM PVH" (as opposed to ARM PV, which does > not utilize hardware extensions) [2]. Although I wasn't able to find > much information about the hardware aspect, what ARM provides seems to > be quite different from VT-x and AMD-V. I'm also confused about what > virt/kvm/arm is. > > Thanks. > > [1]: http://lwn.net/Articles/513940/ > [2]: http://www.xenproject.org/developers/teams/arm-hypervisor.html ARM's virtualization extensions may be a more *natural* match to Xen's semantics and architecture, but that doesn't mean that KVM can't use it. LWN explains the details far better than I can: https://lwn.net/Articles/557132/ virt/kvm/arm is an implementation of KVM (the API) that takes advantage of ARM's virtualization extensions. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/