From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55489) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VEuLB-0006I4-4x for qemu-devel@nongnu.org; Thu, 29 Aug 2013 01:00:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VEuL5-0004OO-6E for qemu-devel@nongnu.org; Thu, 29 Aug 2013 01:00:17 -0400 Message-ID: <1377752389.4028.21.camel@pasglop> From: Benjamin Herrenschmidt Date: Thu, 29 Aug 2013 14:59:49 +1000 In-Reply-To: <20130829045207.GA32466@iris.ozlabs.ibm.com> References: <1377686237-17683-1-git-send-email-aik@ozlabs.ru> <521DD5B7.6070004@suse.de> <20130829033307.GB20680@iris.ozlabs.ibm.com> <20130829045207.GA32466@iris.ozlabs.ibm.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v5] powerpc: add PVR mask support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paul Mackerras Cc: Alexey Kardashevskiy , Alexander Graf , qemu-ppc@nongnu.org, Andreas =?ISO-8859-1?Q?F=E4rber?= , qemu-devel@nongnu.org On Thu, 2013-08-29 at 14:52 +1000, Paul Mackerras wrote: > We are going to need a way to do that for pseries guests. So for > example if we are running on a POWER8 machine and using KVM, we would > want to be able to tell qemu that we want a POWER7 machine and have > qemu put 0x0f000003 in the device tree, and also tell KVM to enable > POWER7 compatibility mode when running the guest, presumably by > setting the PVR for the guest to 0x0f000003. That PVR setting doesn't > (and can't) modify the PVR seen by the guest, since the hardware > doesn't provide any way to virtualize the PVR, but we will make it set > the compatibility mode for the guest. > > How do you think we should handle this in qemu? And how does that relate to what we will do during reconfiguration reboots ? Cheers, Ben.