diff options
| -rw-r--r-- | arch/arm/kvm/arm.c | 18 | ||||
| -rw-r--r-- | include/kvm/arm_arch_timer.h | 2 | ||||
| -rw-r--r-- | virt/kvm/arm/arch_timer.c | 122 |
3 files changed, 110 insertions, 32 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index c378502623f6..ac6e57bcbe4d 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -515,13 +515,7 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu) 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)) - ret = kvm_timer_enable(vcpu); + ret = kvm_timer_enable(vcpu); return ret; } @@ -640,9 +634,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) local_irq_disable(); /* - * Re-check atomic conditions + * If we have a singal pending, or need to notify a userspace + * irqchip about timer level changes, then we exit (and update + * the timer level state in kvm_timer_update_run below). */ - if (signal_pending(current)) { + if (signal_pending(current) || + kvm_timer_should_notify_user(vcpu)) { ret = -EINTR; run->exit_reason = KVM_EXIT_INTR; } @@ -714,6 +711,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) ret = handle_exit(vcpu, run, ret); } + /* Tell userspace about in-kernel device output levels */ + kvm_timer_update_run(vcpu); + if (vcpu->sigset_active) sigprocmask(SIG_SETMASK, &sigsaved, NULL); return ret; diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h index fe797d6ef89d..295584f31a4e 100644 --- a/include/kvm/arm_arch_timer.h +++ b/include/kvm/arm_arch_timer.h @@ -63,6 +63,8 @@ int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu, void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu); void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu); void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu); +bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu); +void kvm_timer_update_run(struct kvm_vcpu *vcpu); void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu); u64 kvm_arm_timer_get_reg(struct kvm_vcpu *, u64 regid); diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 363f0d2cfc79..5dc216748d54 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -184,6 +184,27 @@ bool kvm_timer_should_fire(struct arch_timer_context *timer_ctx) return cval <= now; } +/* + * Reflect the timer output level into the kvm_run structure + */ +void kvm_timer_update_run(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + struct kvm_sync_regs *regs = &vcpu->run->s.regs; + + if (likely(irqchip_in_kernel(vcpu->kvm))) + return; + + /* Populate the device bitmap with the timer states */ + regs->device_irq_level &= ~(KVM_ARM_DEV_EL1_VTIMER | + KVM_ARM_DEV_EL1_PTIMER); + if (vtimer->irq.level) + regs->device_irq_level |= KVM_ARM_DEV_EL1_VTIMER; + if (ptimer->irq.level) + regs->device_irq_level |= KVM_ARM_DEV_EL1_PTIMER; +} + static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level, struct arch_timer_context *timer_ctx) { @@ -194,9 +215,12 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level, trace_kvm_timer_update_irq(vcpu->vcpu_id, timer_ctx->irq.irq, timer_ctx->irq.level); - ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, timer_ctx->irq.irq, - timer_ctx->irq.level); - WARN_ON(ret); + if (likely(irqchip_in_kernel(vcpu->kvm))) { + ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, + timer_ctx->irq.irq, + timer_ctx->irq.level); + WARN_ON(ret); + } } /* @@ -215,7 +239,7 @@ static void kvm_timer_update_state(struct kvm_vcpu *vcpu) * because the guest would never see the interrupt. Instead wait * until we call this function from kvm_timer_flush_hwstate. */ - if (!timer->enabled) + if (unlikely(!timer->enabled)) return; if (kvm_timer_should_fire(vtimer) != vtimer->irq.level) @@ -282,28 +306,12 @@ void kvm_timer_unschedule(struct kvm_vcpu *vcpu) timer_disarm(timer); } -/** - * kvm_timer_flush_hwstate - prepare to move the virt timer to the cpu - * @vcpu: The vcpu pointer - * - * Check if the virtual timer has expired while we were running in the host, - * and inject an interrupt if that was the case. - */ -void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu) +static void kvm_timer_flush_hwstate_vgic(struct kvm_vcpu *vcpu) { - struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); bool phys_active; int ret; - if (unlikely(!timer->enabled)) - return; - - kvm_timer_update_state(vcpu); - - /* Set the background timer for the physical timer emulation. */ - kvm_timer_emulate(vcpu, vcpu_ptimer(vcpu)); - /* * If we enter the guest with the virtual input level to the VGIC * asserted, then we have already told the VGIC what we need to, and @@ -355,11 +363,72 @@ void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu) vtimer->active_cleared_last = !phys_active; } +bool kvm_timer_should_notify_user(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + struct arch_timer_context *ptimer = vcpu_ptimer(vcpu); + struct kvm_sync_regs *sregs = &vcpu->run->s.regs; + bool vlevel, plevel; + + if (likely(irqchip_in_kernel(vcpu->kvm))) + return false; + + vlevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_VTIMER; + plevel = sregs->device_irq_level & KVM_ARM_DEV_EL1_PTIMER; + + return vtimer->irq.level != vlevel || + ptimer->irq.level != plevel; +} + +static void kvm_timer_flush_hwstate_user(struct kvm_vcpu *vcpu) +{ + struct arch_timer_context *vtimer = vcpu_vtimer(vcpu); + + /* + * To prevent continuously exiting from the guest, we mask the + * physical interrupt such that the guest can make forward progress. + * Once we detect the output level being deasserted, we unmask the + * interrupt again so that we exit from the guest when the timer + * fires. + */ + if (vtimer->irq.level) + disable_percpu_irq(host_vtimer_irq); + else + enable_percpu_irq(host_vtimer_irq, 0); +} + +/** + * kvm_timer_flush_hwstate - prepare timers before running the vcpu + * @vcpu: The vcpu pointer + * + * Check if the virtual timer has expired while we were running in the host, + * and inject an interrupt if that was the case, making sure the timer is + * masked or disabled on the host so that we keep executing. Also schedule a + * software timer for the physical timer if it is enabled. + */ +void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu) +{ + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; + + if (unlikely(!timer->enabled)) + return; + + kvm_timer_update_state(vcpu); + + /* Set the background timer for the physical timer emulation. */ + kvm_timer_emulate(vcpu, vcpu_ptimer(vcpu)); + + if (unlikely(!irqchip_in_kernel(vcpu->kvm))) + kvm_timer_flush_hwstate_user(vcpu); + else + kvm_timer_flush_hwstate_vgic(vcpu); +} + /** * kvm_timer_sync_hwstate - sync timer state from cpu * @vcpu: The vcpu pointer * - * Check if the virtual timer has expired while we were running in the guest, + * Check if any of the timers have expired while we were running in the guest, * and inject an interrupt if that was the case. */ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) @@ -559,6 +628,13 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu) if (timer->enabled) return 0; + /* Without a VGIC we do not map virtual IRQs to physical IRQs */ + if (!irqchip_in_kernel(vcpu->kvm)) + goto no_vgic; + + if (!vgic_initialized(vcpu->kvm)) + return -ENODEV; + /* * Find the physical IRQ number corresponding to the host_vtimer_irq */ @@ -582,8 +658,8 @@ int kvm_timer_enable(struct kvm_vcpu *vcpu) if (ret) return ret; +no_vgic: timer->enabled = 1; - return 0; } |