From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Liu, Jinsong" Subject: RE: [Xen-devel] [PATCH 1/2] RFC: Prepare PAD for native and xen platform Date: Thu, 5 Apr 2012 13:01:45 +0000 Message-ID: References: <4F46530B020000780007F751@nat28.tlf.novell.com> <20120226173458.GB18098@phenom.dumpdata.com> <20120326164835.GE10236@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Return-path: Received: from mga14.intel.com ([143.182.124.37]:7646 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751840Ab2DENBt convert rfc822-to-8bit (ORCPT ); Thu, 5 Apr 2012 09:01:49 -0400 In-Reply-To: <20120326164835.GE10236@phenom.dumpdata.com> Content-Language: en-US Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Konrad Rzeszutek Wilk Cc: "Brown, Len" , "xen-devel@lists.xensource.com" , "linux-kernel@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "keir.xen@gmail.com" , Jan Beulich , "Li, Shaohua" , "lenb@kernel.org" Konrad Rzeszutek Wilk wrote: >>> Compare approaches: >>> >>> 1. xen overwritten approach (patches V2, x86_init, osl approach) >>> Pros: a little simpler code >>> Cons: >>> 1). specific to xen, cannot extend to other virt platform; >>> 2). need to change natvie acpi_pad as modular; >>> >>> 2. paravirt interface approach (original patches V1) Pros: >>> 1). standard hypervisor-agnostic interface (USENIX >>> conference 2006), can easily hook to Xen/lguest/... on >>> demand; 2). arch independent; 3). no need to change native >>> acpi_pad as non-modular; Cons: a little complicated >>> code, and code patching is some >>> overkilled for this case (but no harm); >>> >>> (BTW, in the future we need add more and more pv ops, like >>> pv_pm_ops, pv_cpu_hotplug_ops, pv_mem_hotplug_ops, etc. So how >>> about add a pv_misc_ops template to handle them all? seems it's a >>> common issue). >>> > > I think (and you probabaly have a better idea) is that the maintainer > of drivers/acpi/* is not very open to adding in code that only > benefits Xen. > > If it benefits other architectures (say ARM) then adding in hooks > there (in osl for example) makes sense - but I am not sure if ARM has > a form > of _PUR code/calls it needs to do. > > So with that in mind, neither of those options seems proper - as all > of them depend on changing something in drivers/acpi/*. > > I've one or two suggestions of what could be done to still make this > work, but I need you to first see what happens if the native acpi_pad > runs under Xen with the latest upstream code (along with three patches > that are in a BZ I pointed you too). Konrad, any new idea? seems we hardly totally walk around acpi staff. Thanks, Jinsong