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[209.132.180.67]) by mx.google.com with ESMTP id kb15si8572586pad.2.2014.11.14.07.55.46 for ; Fri, 14 Nov 2014 07:55:47 -0800 (PST) Received-SPF: none (google.com: linux-kernel-owner@vger.kernel.org does not designate permitted sender hosts) client-ip=209.132.180.67; Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161321AbaKNPzp (ORCPT + 26 others); Fri, 14 Nov 2014 10:55:45 -0500 Received: from service87.mimecast.com ([91.220.42.44]:51077 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161272AbaKNPzn convert rfc822-to-8bit (ORCPT ); Fri, 14 Nov 2014 10:55:43 -0500 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Fri, 14 Nov 2014 15:55:39 +0000 Received: from [10.1.209.143] ([10.1.255.212]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Fri, 14 Nov 2014 15:55:37 +0000 Message-ID: <546625F8.6060900@arm.com> Date: Fri, 14 Nov 2014 15:55:36 +0000 From: Marc Zyngier User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130330 Thunderbird/17.0.5 MIME-Version: 1.0 To: Chen Gang CC: "christoffer.dall@linaro.org" , "gleb@kernel.org" , Paolo Bonzini , "linux@arm.linux.org.uk" , Catalin Marinas , Will Deacon , "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.cs.columbia.edu" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2] virt: kvm: arm: vgic: Process the failure case when kvm_register_device_ops() fails References: <54661D5F.3060304@gmail.com> In-Reply-To: <54661D5F.3060304@gmail.com> X-Enigmail-Version: 1.4.6 X-OriginalArrivalTime: 14 Nov 2014 15:55:37.0082 (UTC) FILETIME=[6E75E5A0:01D00023] X-MC-Unique: 114111415553903001 Sender: linux-kernel-owner@vger.kernel.org Precedence: list List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: marc.zyngier@arm.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.217.181 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , On 14/11/14 15:18, Chen Gang wrote: > When kvm_register_device_ops() fails, need disable_percpu_irq(), need > vgic_arch_unsetup(), need __unregister_cpu_notifier(), and also need > free_percpu_irq(). > > At present, there is no vgic_arch_unsetup(), so add it for resetting > '__vgic_sr_vectors'. > > > Signed-off-by: Chen Gang > --- > arch/arm/include/asm/kvm_host.h | 1 + > arch/arm64/include/asm/kvm_host.h | 8 ++++++++ > virt/kvm/arm/vgic.c | 19 +++++++++++++++++-- > 3 files changed, 26 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h > index 53036e2..f68e302 100644 > --- a/arch/arm/include/asm/kvm_host.h > +++ b/arch/arm/include/asm/kvm_host.h > @@ -232,6 +232,7 @@ static inline void vgic_arch_setup(const struct vgic_params *vgic) > { > BUG_ON(vgic->type != VGIC_V2); > } > +static inline void vgic_arch_unsetup(void) {} > > int kvm_perf_init(void); > int kvm_perf_teardown(void); > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > index 2012c4b..597500c 100644 > --- a/arch/arm64/include/asm/kvm_host.h > +++ b/arch/arm64/include/asm/kvm_host.h > @@ -248,6 +248,14 @@ static inline void vgic_arch_setup(const struct vgic_params *vgic) > } > } > > +static inline void vgic_arch_unsetup(void) > +{ > + extern struct vgic_sr_vectors __vgic_sr_vectors; > + > + __vgic_sr_vectors.save_vgic = 0; > + __vgic_sr_vectors.restore_vgic = 0; > +} > + > static inline void kvm_arch_hardware_disable(void) {} > static inline void kvm_arch_hardware_unsetup(void) {} > static inline void kvm_arch_sync_events(struct kvm *kvm) {} > diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c > index 3aaca49..bab81f7 100644 > --- a/virt/kvm/arm/vgic.c > +++ b/virt/kvm/arm/vgic.c > @@ -2405,6 +2405,11 @@ static void vgic_init_maintenance_interrupt(void *info) > enable_percpu_irq(vgic->maint_irq, 0); > } > > +static void vgic_uninit_maintenance_interrupt(void *info) > +{ > + disable_percpu_irq(vgic->maint_irq); > +} > + > static int vgic_cpu_notify(struct notifier_block *self, > unsigned long action, void *cpu) > { > @@ -2470,9 +2475,19 @@ int kvm_vgic_hyp_init(void) > > on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1); > > - return kvm_register_device_ops(&kvm_arm_vgic_v2_ops, > - KVM_DEV_TYPE_ARM_VGIC_V2); > + ret = kvm_register_device_ops(&kvm_arm_vgic_v2_ops, > + KVM_DEV_TYPE_ARM_VGIC_V2); > + if (ret) { > + kvm_err("Cannot register device ops\n"); > + goto out_disable_irq; > + } > + > + return 0; > > +out_disable_irq: > + on_each_cpu(vgic_uninit_maintenance_interrupt, NULL, 1); > + vgic_arch_unsetup(); > + __unregister_cpu_notifier(&vgic_cpu_nb); > out_free_irq: > free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus()); > return ret; > No. This is completely overdesigned, and fixes something that really cannot happen. What is wrong with: This achieves the exact same effect. Thanks, M. diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index 3aaca49..b7dffa80 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -2465,13 +2465,17 @@ int kvm_vgic_hyp_init(void) goto out_free_irq; } + ret = kvm_register_device_ops(&kvm_arm_vgic_v2_ops, + KVM_DEV_TYPE_ARM_VGIC_V2); + if (ret) + goto out_free_irq; + /* Callback into for arch code for setup */ vgic_arch_setup(vgic); on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1); - return kvm_register_device_ops(&kvm_arm_vgic_v2_ops, - KVM_DEV_TYPE_ARM_VGIC_V2); + return 0; out_free_irq: free_percpu_irq(vgic->maint_irq, kvm_get_running_vcpus());