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[209.132.180.67]) by mx.google.com with ESMTP id lj11si69631040pab.25.2015.06.30.03.51.38; Tue, 30 Jun 2015 03:51:39 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of stable-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752955AbbF3Kvc (ORCPT + 2 others); Tue, 30 Jun 2015 06:51:32 -0400 Received: from mail-pd0-f173.google.com ([209.85.192.173]:35383 "EHLO mail-pd0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752182AbbF3Kv2 (ORCPT ); Tue, 30 Jun 2015 06:51:28 -0400 Received: by pdbci14 with SMTP id ci14so4277611pdb.2 for ; Tue, 30 Jun 2015 03:51:28 -0700 (PDT) X-Received: by 10.68.219.42 with SMTP id pl10mr42665281pbc.154.1435661488034; Tue, 30 Jun 2015 03:51:28 -0700 (PDT) Received: from localhost ([120.136.36.232]) by mx.google.com with ESMTPSA id k9sm45119578pbq.71.2015.06.30.03.51.25 (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 30 Jun 2015 03:51:26 -0700 (PDT) From: shannon.zhao@linaro.org To: stable@vger.kernel.org Cc: gregkh@linuxfoundation.org, christoffer.dall@linaro.org, shannon.zhao@linaro.org Subject: [PATCH for 3.14.y stable 18/22] arm/arm64: KVM: Require in-kernel vgic for the arch timers Date: Tue, 30 Jun 2015 18:49:06 +0800 Message-Id: <1435661350-8060-19-git-send-email-shannon.zhao@linaro.org> X-Mailer: git-send-email 1.9.5.msysgit.1 In-Reply-To: <1435661350-8060-1-git-send-email-shannon.zhao@linaro.org> References: <1435661350-8060-1-git-send-email-shannon.zhao@linaro.org> Sender: stable-owner@vger.kernel.org Precedence: list List-ID: X-Mailing-List: stable@vger.kernel.org X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: shannon.zhao@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.215.44 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: , From: Christoffer Dall commit 05971120fca43e0357789a14b3386bb56eef2201 upstream. It is curently possible to run a VM with architected timers support without creating an in-kernel VGIC, which will result in interrupts from the virtual timer going nowhere. To address this issue, move the architected timers initialization to the time when we run a VCPU for the first time, and then only initialize (and enable) the architected timers if we have a properly created and initialized in-kernel VGIC. When injecting interrupts from the virtual timer to the vgic, the current setup should ensure that this never calls an on-demand init of the VGIC, which is the only call path that could return an error from kvm_vgic_inject_irq(), so capture the return value and raise a warning if there's an error there. We also change the kvm_timer_init() function from returning an int to be a void function, since the function always succeeds. Reviewed-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Shannon Zhao --- arch/arm/kvm/arm.c | 13 +++++++++++-- include/kvm/arm_arch_timer.h | 10 ++++------ virt/kvm/arm/arch_timer.c | 30 ++++++++++++++++++++++-------- 3 files changed, 37 insertions(+), 16 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 2e74a61..f6a52a2 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -441,6 +441,7 @@ static void update_vttbr(struct kvm *kvm) static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) { + struct kvm *kvm = vcpu->kvm; int ret; if (likely(vcpu->arch.has_run_once)) @@ -452,12 +453,20 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) * Initialize the VGIC before running a vcpu the first time on * this VM. */ - if (unlikely(!vgic_initialized(vcpu->kvm))) { - ret = kvm_vgic_init(vcpu->kvm); + if (unlikely(!vgic_initialized(kvm))) { + ret = kvm_vgic_init(kvm); if (ret) return ret; } + /* + * Enable the arch timers only if we have an in-kernel VGIC + * and it has been properly initialized, since we cannot handle + * interrupts from the virtual timer with a userspace gic. + */ + if (irqchip_in_kernel(kvm) && vgic_initialized(kvm)) + kvm_timer_enable(kvm); + return 0; } diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index 6d9aedd..327b155 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -60,7 +60,8 @@ struct arch_timer_cpu { #ifdef CONFIG_KVM_ARM_TIMER int kvm_timer_hyp_init(void); -int kvm_timer_init(struct kvm *kvm); +void kvm_timer_enable(struct kvm *kvm); +void kvm_timer_init(struct kvm *kvm); void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu, const struct kvm_irq_level *irq); void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu); @@ -73,11 +74,8 @@ static inline int kvm_timer_hyp_init(void) return 0; }; -static inline int kvm_timer_init(struct kvm *kvm) -{ - return 0; -} - +static inline void kvm_timer_enable(struct kvm *kvm) {} +static inline void kvm_timer_init(struct kvm *kvm) {} static inline void kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu, const struct kvm_irq_level *irq) {} static inline void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) {} diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 5081e80..c6fe405 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -61,12 +61,14 @@ static void timer_disarm(struct arch_timer_cpu *timer) static void kvm_timer_inject_irq(struct kvm_vcpu *vcpu) { + int ret; struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; timer->cntv_ctl |= ARCH_TIMER_CTRL_IT_MASK; - kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, - timer->irq->irq, - timer->irq->level); + ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, + timer->irq->irq, + timer->irq->level); + WARN_ON(ret); } static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id) @@ -307,12 +309,24 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) timer_disarm(timer); } -int kvm_timer_init(struct kvm *kvm) +void kvm_timer_enable(struct kvm *kvm) { - if (timecounter && wqueue) { - kvm->arch.timer.cntvoff = kvm_phys_timer_read(); + if (kvm->arch.timer.enabled) + return; + + /* + * There is a potential race here between VCPUs starting for the first + * time, which may be enabling the timer multiple times. That doesn't + * hurt though, because we're just setting a variable to the same + * variable that it already was. The important thing is that all + * VCPUs have the enabled variable set, before entering the guest, if + * the arch timers are enabled. + */ + if (timecounter && wqueue) kvm->arch.timer.enabled = 1; - } +} - return 0; +void kvm_timer_init(struct kvm *kvm) +{ + kvm->arch.timer.cntvoff = kvm_phys_timer_read(); }