Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751376AbdH3JqK (ORCPT ); Wed, 30 Aug 2017 05:46:10 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:41774 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750835AbdH3JqJ (ORCPT ); Wed, 30 Aug 2017 05:46:09 -0400 Subject: Re: [PATCH v3 39/59] KVM: arm/arm64: GICv4: Add property field and per-VM predicate To: Christoffer Dall Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Christoffer Dall , Thomas Gleixner , Jason Cooper , Eric Auger , Shanker Donthineni , Mark Rutland , Shameerali Kolothum Thodi References: <20170731172637.29355-1-marc.zyngier@arm.com> <20170731172637.29355-40-marc.zyngier@arm.com> <20170826194915.GE11074@cbox> From: Marc Zyngier Organization: ARM Ltd Message-ID: <45590bb0-0d0e-668f-5553-0443ef8de9a5@arm.com> Date: Wed, 30 Aug 2017 10:46:05 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170826194915.GE11074@cbox> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2068 Lines: 65 On 26/08/17 20:49, Christoffer Dall wrote: > On Mon, Jul 31, 2017 at 06:26:17PM +0100, Marc Zyngier wrote: >> Add a new has_gicv4 field in the global VGIC state that indicates >> whether the HW is GICv4 capable, as a per-VM predicate indicating >> if there is a possibility for a VM to support direct injection >> (the above being true and the VM having an ITS). >> >> Signed-off-by: Marc Zyngier >> --- >> include/kvm/arm_vgic.h | 3 +++ >> virt/kvm/arm/vgic/vgic-mmio-v3.c | 5 +++++ >> virt/kvm/arm/vgic/vgic.h | 2 ++ >> 3 files changed, 10 insertions(+) >> >> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h >> index ee8587c8c715..84694b42373a 100644 >> --- a/include/kvm/arm_vgic.h >> +++ b/include/kvm/arm_vgic.h >> @@ -73,6 +73,9 @@ struct vgic_global { >> /* Only needed for the legacy KVM_CREATE_IRQCHIP */ >> bool can_emulate_gicv2; >> >> + /* Does have GICv4? */ > > nit: questionable comment, how about > > /* Hardware has GICv4? */ > or > /* Do we have GICv4? */ Yup, reads much better. >> + bool has_gicv4; >> + >> /* GIC system register CPU interface */ >> struct static_key_false gicv3_cpuif; >> >> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c >> index 714fa3933546..74109ca75cc0 100644 >> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c >> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c >> @@ -54,6 +54,11 @@ bool vgic_has_its(struct kvm *kvm) >> return dist->has_its; >> } >> >> +bool vgic_is_v4_capable(struct kvm *kvm) >> +{ >> + return kvm_vgic_global_state.has_gicv4 && vgic_has_its(kvm); >> +} >> + > > uber nit: the naming here is a bit funny, because we won't be presenting > a GICv4 GIC to the guest, so I'd prefer something like > vgic_supports_direct_msis() or something like that, but this is > obviously not a deal breaker. I like it. It has the advantage of not tying the predicate to a particular direct injection method, should we one day have a GICv6 (no, please...). Thanks, M. -- Jazz is not dead. It just smells funny...