From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: [PATCH V1 0/7] Enable ACPI support for ARM KVM GIC Date: Mon, 8 Feb 2016 16:42:30 +0000 Message-ID: <56B8C576.5000801@arm.com> References: <1454692054-8984-1-git-send-email-wei@redhat.com> <56B866FD.4070104@arm.com> <56B8C3C8.2070204@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: christoffer.dall@linaro.org, kvm@vger.kernel.org, hanjun.guo@linaro.org, fu.wei@linaro.org, drjones@redhat.com, al.stone@linaro.org, Julien Grall To: Wei Huang , kvmarm@lists.cs.columbia.edu Return-path: Received: from foss.arm.com ([217.140.101.70]:34292 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751168AbcBHQmd (ORCPT ); Mon, 8 Feb 2016 11:42:33 -0500 In-Reply-To: <56B8C3C8.2070204@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 08/02/16 16:35, Wei Huang wrote: > > > On 2/8/16 03:59, Marc Zyngier wrote: >> Wei, >> >> On 05/02/16 17:07, Wei Huang wrote: >>> This patch set enables ACPI support for KVM GIC. Note that the patches >>> are in fact the V3 of previously submitted patches (search "Enable ACPI >>> support for KVM ARM"). But because Fu Wei includes the arch_timer part >>> in his series [1] and I have substantially re-written the GIC code in this >>> revision, the version number is reset to v1. >>> >>> By following Marc's prior comments, the main design idea is to let DT or >>> ACPI code to fill out the "struct vgic_params" which are extended to >>> include all GIC related info. >> >> I think you misread the comments I gave back in June (!), where I said: >> >> >> [...] >> >> Simply making available a global structure containing the base addresses >> and interrupt should be enough, and could be shared with both DT and >> ACPI. You could start your series by letting both GIC drivers expose >> that information obtained through DT, convert KVM to use this structure, >> and later on let ACPI fill in this structure too. >> >>> Anyway the difficulty is to find a common place to store and share info >>> between other modules & KVM. >> >> Indeed. As a rule of thumb, I want to minimize the amount of gratuitous >> divergence between DT and ACPI. So the sooner we extract the required >> information from whatever firmware we have, the better. >> >> >>> >>> [1] https://lkml.org/lkml/2016/2/1/658 >>> >>> Thanks, >>> -Wei >>> >>> Wei Huang (7): >>> KVM: GIC: Move GIC DT probing code to GICv2 and GICv3 files >>> KVM: GIC: Add extra fields to store GICH and GICV resource info >>> KVM: GIC: Create a common probe function for GIC >>> KVM: GICv2: Extract the common code from DT >>> KVM: GICv2: Add ACPI probing function >>> KVM: GICv3: Extract the common code from DT >>> KVM: GICv3: Add ACPI probing function >>> >>> include/kvm/arm_vgic.h | 14 ++-- >>> virt/kvm/arm/vgic-v2-emul.c | 4 +- >>> virt/kvm/arm/vgic-v2.c | 186 +++++++++++++++++++++++++++++++++----------- >>> virt/kvm/arm/vgic-v3.c | 159 ++++++++++++++++++++++++++++--------- >>> virt/kvm/arm/vgic.c | 22 +----- >>> 5 files changed, 277 insertions(+), 108 deletions(-) >>> >> >> So when I see this diffstat and the patches that follow, I cannot help >> but think that we do have a disconnect here. You do add a bunch of ACPI >> probing in KVM, to which I've already said no. >> >> I want to see the probing code in the GIC drivers, exported through a >> common structure that KVM can then use. That's it. Nothing else. > > OK. I will create a V2 based on that idea. You may want to synchronize with Julien (on CC), which has been working on such a thing for a while. Thanks, M. -- Jazz is not dead. It just smells funny...