From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54263) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VEuDa-000487-LD for qemu-devel@nongnu.org; Thu, 29 Aug 2013 00:52:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VEuDU-0001xt-MC for qemu-devel@nongnu.org; Thu, 29 Aug 2013 00:52:26 -0400 Date: Thu, 29 Aug 2013 14:52:08 +1000 From: Paul Mackerras Message-ID: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20130829033307.GB20680@iris.ozlabs.ibm.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v5] powerpc: add PVR mask support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andreas =?iso-8859-1?Q?F=E4rber?= Cc: Alexey Kardashevskiy , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, Alexander Graf On Thu, Aug 29, 2013 at 01:33:07PM +1000, Paul Mackerras wrote: > On Wed, Aug 28, 2013 at 12:49:27PM +0200, Andreas F=E4rber wrote: >=20 > > According to the only reply I received, it's "POWER7", not "POWER7+" = - > > see my patch description. If that information was wrong, we'll need t= o > > move POWER7P introduction before my fw_name patch and update it accor= dingly. >=20 > It should be "POWER7+" for consistency with other hypervisors and > firmware. Actually, on a POWER7+ machine under PowerVM here, I am seeing PowerPC,POWER7@xxx --- but PowerVM is running the partition in v2.06 architected mode rather than POWER7+ native mode. I'm not sure at the moment how to get it to run in POWER7+ native mode (or even if there is such a thing). In any case, I don't think it really matters whether it's PowerPC,POWER7 or PowerPC,POWER7+. Which brings me to another question. PAPR specifies that when a partition is being run in a compatibility mode for an older processor, the cpu-version property in the cpu nodes has a "logical PVR" value representing the architecture level of the compatibility mode; for example, 0x0f000001 for architecture 2.04, 0x0f000002 for 2.05 (POWER6), 0x0f000003 for 2.06 (POWER7), 0x0f000004 for 2.07 (POWER8). 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? Regards, Paul.