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. Signed-off-by: Christoffer Dall <[email protected]> --- arch/arm/kvm/arm.c | 15 +++++++++++---- include/kvm/arm_arch_timer.h | 2 +- virt/kvm/arm/arch_timer.c | 15 ++++++++++----- 3 files changed, 22 insertions(+), 10 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index d4da244..06f0431 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -127,8 +127,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) if (ret) goto out_free_stage2_pgd; - kvm_timer_init(kvm); - /* Mark the initial VMID generation invalid */ kvm->arch.vmid_gen = 0; @@ -424,6 +422,7 @@ 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)) @@ -435,12 +434,20 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) * Map the VGIC hardware resources before running a vcpu the first * time on this VM. */ - if (unlikely(!vgic_ready(vcpu->kvm))) { - ret = kvm_vgic_map_resources(vcpu->kvm); + if (unlikely(!vgic_ready(kvm))) { + ret = kvm_vgic_map_resources(kvm); if (ret) return ret; } + /* + * Initialize the Architected 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 vgic. + */ + if (irqchip_in_kernel(kvm) && vgic_initialized(kvm)) + kvm_timer_init(kvm); + return 0; } diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index ad9db60..c9bd045 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -60,7 +60,7 @@ 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_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); diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 22fa819..48ce5cb 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 +309,15 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) timer_disarm(timer); } -int kvm_timer_init(struct kvm *kvm) +void kvm_timer_init(struct kvm *kvm) { + if (kvm->arch.timer.enabled) + return; + if (timecounter && wqueue) { kvm->arch.timer.cntvoff = kvm_phys_timer_read(); kvm->arch.timer.enabled = 1; } - return 0; + return; } -- 2.1.2.330.g565301e.dirty -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
