From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Subject: Re: [PATCH 27/27] KVM: PPC: Add Documentation about PV interface Date: Fri, 2 Jul 2010 14:10:03 -0500 Message-ID: <20100702141003.75302a9a@schlenkerla.am.freescale.net> References: <1277980982-12433-1-git-send-email-agraf@suse.de> <1277980982-12433-28-git-send-email-agraf@suse.de> <3085B58A-01A1-4B5C-A0E7-024DCFDFD4B2@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Hollis Blanchard , kvm-ppc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, KVM list , linuxppc-dev , Stuart Yoder , Dan Hettena , Jimi Xenidis To: Alexander Graf Return-path: In-Reply-To: <3085B58A-01A1-4B5C-A0E7-024DCFDFD4B2-l3A5Bk7waGM@public.gmane.org> Sender: kvm-ppc-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: kvm.vger.kernel.org On Fri, 2 Jul 2010 20:47:44 +0200 Alexander Graf wrote: > > On 02.07.2010, at 19:59, Hollis Blanchard wrote: > > > [Resending...] > > > > Please reconcile this with > > http://www.linux-kvm.org/page/PowerPC_Hypercall_ABI, which has been > > discussed in the (admittedly closed) Power.org embedded hypervisor > > working group. Bear in mind that other hypervisors are already > > implementing the documented ABI, so if you have concerns, you should > > probably raise them with that audience... > > We can not use sc with LV=1 because that would break the KVM in > something else case which is KVM's strong point on PPC. The current proposal involves the hypervisor specifying the hcall opcode sequence in the device tree -- to allow either "sc 1" or "sc 0 plus magic GPR" depending on whether you've got the hardware hypervisor feature (hereafter HHV). With HHV, "sc 0 plus magic GPR" just doesn't work, since it won't trap to the hypervisor. "sc 1 plus magic GPR" might be problematic on some non-HHV implementations, especially if you *do* have HHV but the non-HHV hypervisor is running as an HHV guest. -Scott From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from az33egw02.freescale.net (az33egw02.freescale.net [192.88.158.103]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "az33egw02.freescale.net", Issuer "Thawte Premium Server CA" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id C86ECB70C0 for ; Sat, 3 Jul 2010 05:10:11 +1000 (EST) Received: from de01smr01.freescale.net (de01smr01.freescale.net [10.208.0.31]) by az33egw02.freescale.net (8.14.3/az33egw02) with ESMTP id o62JA5Xd005676 for ; Fri, 2 Jul 2010 12:10:05 -0700 (MST) Received: from az33exm25.fsl.freescale.net (az33exm25.am.freescale.net [10.64.32.16]) by de01smr01.freescale.net (8.13.1/8.13.0) with ESMTP id o62JLkRV019520 for ; Fri, 2 Jul 2010 14:21:46 -0500 (CDT) Date: Fri, 2 Jul 2010 14:10:03 -0500 From: Scott Wood To: Alexander Graf Subject: Re: [PATCH 27/27] KVM: PPC: Add Documentation about PV interface Message-ID: <20100702141003.75302a9a@schlenkerla.am.freescale.net> In-Reply-To: <3085B58A-01A1-4B5C-A0E7-024DCFDFD4B2@suse.de> References: <1277980982-12433-1-git-send-email-agraf@suse.de> <1277980982-12433-28-git-send-email-agraf@suse.de> <3085B58A-01A1-4B5C-A0E7-024DCFDFD4B2@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: KVM list , kvm-ppc@vger.kernel.org, Dan Hettena , linuxppc-dev , Hollis Blanchard List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2 Jul 2010 20:47:44 +0200 Alexander Graf wrote: > > On 02.07.2010, at 19:59, Hollis Blanchard wrote: > > > [Resending...] > > > > Please reconcile this with > > http://www.linux-kvm.org/page/PowerPC_Hypercall_ABI, which has been > > discussed in the (admittedly closed) Power.org embedded hypervisor > > working group. Bear in mind that other hypervisors are already > > implementing the documented ABI, so if you have concerns, you should > > probably raise them with that audience... > > We can not use sc with LV=1 because that would break the KVM in > something else case which is KVM's strong point on PPC. The current proposal involves the hypervisor specifying the hcall opcode sequence in the device tree -- to allow either "sc 1" or "sc 0 plus magic GPR" depending on whether you've got the hardware hypervisor feature (hereafter HHV). With HHV, "sc 0 plus magic GPR" just doesn't work, since it won't trap to the hypervisor. "sc 1 plus magic GPR" might be problematic on some non-HHV implementations, especially if you *do* have HHV but the non-HHV hypervisor is running as an HHV guest. -Scott From mboxrd@z Thu Jan 1 00:00:00 1970 From: Scott Wood Date: Fri, 02 Jul 2010 19:10:03 +0000 Subject: Re: [PATCH 27/27] KVM: PPC: Add Documentation about PV interface Message-Id: <20100702141003.75302a9a@schlenkerla.am.freescale.net> List-Id: References: <1277980982-12433-1-git-send-email-agraf@suse.de> <1277980982-12433-28-git-send-email-agraf@suse.de> <3085B58A-01A1-4B5C-A0E7-024DCFDFD4B2@suse.de> In-Reply-To: <3085B58A-01A1-4B5C-A0E7-024DCFDFD4B2-l3A5Bk7waGM@public.gmane.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alexander Graf Cc: Hollis Blanchard , kvm-ppc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, KVM list , linuxppc-dev , Stuart Yoder , Dan Hettena , Jimi Xenidis On Fri, 2 Jul 2010 20:47:44 +0200 Alexander Graf wrote: > > On 02.07.2010, at 19:59, Hollis Blanchard wrote: > > > [Resending...] > > > > Please reconcile this with > > http://www.linux-kvm.org/page/PowerPC_Hypercall_ABI, which has been > > discussed in the (admittedly closed) Power.org embedded hypervisor > > working group. Bear in mind that other hypervisors are already > > implementing the documented ABI, so if you have concerns, you should > > probably raise them with that audience... > > We can not use sc with LV=1 because that would break the KVM in > something else case which is KVM's strong point on PPC. The current proposal involves the hypervisor specifying the hcall opcode sequence in the device tree -- to allow either "sc 1" or "sc 0 plus magic GPR" depending on whether you've got the hardware hypervisor feature (hereafter HHV). With HHV, "sc 0 plus magic GPR" just doesn't work, since it won't trap to the hypervisor. "sc 1 plus magic GPR" might be problematic on some non-HHV implementations, especially if you *do* have HHV but the non-HHV hypervisor is running as an HHV guest. -Scott