From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56743) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X0Yne-00020n-Rg for qemu-devel@nongnu.org; Fri, 27 Jun 2014 12:15:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X0YnX-0006qQ-Tt for qemu-devel@nongnu.org; Fri, 27 Jun 2014 12:14:54 -0400 Message-ID: <53AD9876.20903@suse.de> Date: Fri, 27 Jun 2014 18:14:46 +0200 From: Alexander Graf MIME-Version: 1.0 References: <1403884480-25547-1-git-send-email-aik@ozlabs.ru> In-Reply-To: <1403884480-25547-1-git-send-email-aik@ozlabs.ru> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH] target-ppc: Add compatibility between P7/P7+ and P8E/P8 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy , qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org On 27.06.14 17:54, Alexey Kardashevskiy wrote: > At the moment POWER7+ and POWER7 CPUs are different incompatible > families in QOM. The same is valid for POWER8E and POWER8 CPUs. > However, these couples are architecturally equal and there is no > good reason, for example, not to let run -cpu POWER7 on the real > POWER7+ CPU machine. > > This introduces one more level in hierarchy of POWERPC CPU classes. > New macro POWERPC_FAMILY_2 takes a family class and the parent family > class and, for example, for POWER7+ the hierarchy looks like: > TYPE_CPU > TYPE_POWERPC_CPU > POWER7-powerpc64-cpu > POWER7+-powerpc64-cpu > > This registers new dynamic POWERPC CPU classes for all classes between > the lowest one which matches the real PVR and TYPE_POWERPC_CPU. > So for POWER7, it is still going to be just a single dynamic "POWER7" > class but for POWER7+ inherited from POWER7 there are going to be > 2 dynamic classes - "POWER7+" and "POWER7" so management software > can use both to ensure successful migration. > > Since POWER7+ inherits from POWER7 and POWER8E from POWER8, this > removes recurring pieces of code. CPUs with shorter names were chosen > as parents. > > Signed-off-by: Alexey Kardashevskiy > --- > > This is rather RFC patch and there is no hurry in reviewing this, > and this is not 2.1 material and everyhting, just tried to solve > a QOM puzzle here :) I'm not sure - I'd rather make sure we have this sorted out for 2.1 so we can keep the -cpu list stable. Could we make the PVR matching a function callback rather than value+mask? Then we could have p7 and p8 just match on 2 different PVR ranges. Alex