diff mbox

[v3,4/5] KVM: arm/arm64: Report PMU overflow interrupts to userspace irqchip

Message ID 20170405092815.22503-5-cdall@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Christoffer Dall April 5, 2017, 9:28 a.m. UTC 
From: Christoffer Dall <christoffer.dall@linaro.org>

When not using an in-kernel VGIC, but instead emulating an interrupt
controller in userspace, we should report the PMU overflow status to
that userspace interrupt controller using the KVM_CAP_ARM_USER_IRQ
feature.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/kvm/arm.c    |  9 ++++++---
 include/kvm/arm_pmu.h |  7 +++++++
 virt/kvm/arm/pmu.c    | 42 ++++++++++++++++++++++++++++++++++++++----
 3 files changed, 51 insertions(+), 7 deletions(-)

Comments

Marc Zyngier April 6, 2017, 5:12 p.m. UTC | #1 
On 05/04/17 10:28, Christoffer Dall wrote:
> From: Christoffer Dall <christoffer.dall@linaro.org>
> 
> When not using an in-kernel VGIC, but instead emulating an interrupt
> controller in userspace, we should report the PMU overflow status to
> that userspace interrupt controller using the KVM_CAP_ARM_USER_IRQ
> feature.
> 
> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
> ---
>  arch/arm/kvm/arm.c    |  9 ++++++---
>  include/kvm/arm_pmu.h |  7 +++++++
>  virt/kvm/arm/pmu.c    | 42 ++++++++++++++++++++++++++++++++++++++----
>  3 files changed, 51 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index efb16e5..f935383 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -635,11 +635,13 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  
>  		/*
>  		 * 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).
> +		 * irqchip about timer or PMU level changes, then we exit (and
> +		 * update the timer level state in kvm_timer_update_run
> +		 * below).
>  		 */
>  		if (signal_pending(current) ||
> -		    kvm_timer_should_notify_user(vcpu)) {
> +		    kvm_timer_should_notify_user(vcpu) ||
> +		    kvm_pmu_should_notify_user(vcpu)) {
>  			ret = -EINTR;
>  			run->exit_reason = KVM_EXIT_INTR;
>  		}
> @@ -713,6 +715,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
>  
>  	/* Tell userspace about in-kernel device output levels */
>  	kvm_timer_update_run(vcpu);
> +	kvm_pmu_update_run(vcpu);

Very minor nit: as we now have a couple of functions that are going to
check the same thing (irqchip_in_kernel), we could consider moving the
test here.  I don't have strong feelings about it though.

Thanks,

	M.
diff mbox

Patch

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index efb16e5..f935383 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -635,11 +635,13 @@  int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 		/*
 		 * 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).
+		 * irqchip about timer or PMU level changes, then we exit (and
+		 * update the timer level state in kvm_timer_update_run
+		 * below).
 		 */
 		if (signal_pending(current) ||
-		    kvm_timer_should_notify_user(vcpu)) {
+		    kvm_timer_should_notify_user(vcpu) ||
+		    kvm_pmu_should_notify_user(vcpu)) {
 			ret = -EINTR;
 			run->exit_reason = KVM_EXIT_INTR;
 		}
@@ -713,6 +715,7 @@  int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 	/* Tell userspace about in-kernel device output levels */
 	kvm_timer_update_run(vcpu);
+	kvm_pmu_update_run(vcpu);
 
 	if (vcpu->sigset_active)
 		sigprocmask(SIG_SETMASK, &sigsaved, NULL);
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 92e7e97..1ab4633 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -50,6 +50,8 @@  void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu);
 void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu);
+bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu);
+void kvm_pmu_update_run(struct kvm_vcpu *vcpu);
 void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val);
 void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
@@ -85,6 +87,11 @@  static inline void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu) {}
 static inline void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu) {}
+static inline bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu)
+{
+	return false;
+}
+static inline void kvm_pmu_update_run(struct kvm_vcpu *vcpu) {}
 static inline void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) {}
 static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 69ccce3..51218be 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -230,13 +230,47 @@  static void kvm_pmu_update_state(struct kvm_vcpu *vcpu)
 		return;
 
 	overflow = !!kvm_pmu_overflow_status(vcpu);
-	if (pmu->irq_level != overflow) {
-		pmu->irq_level = overflow;
-		kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
-				    pmu->irq_num, overflow);
+	if (pmu->irq_level == overflow)
+		return;
+
+	pmu->irq_level = overflow;
+
+	if (likely(irqchip_in_kernel(vcpu->kvm))) {
+		int ret;
+		ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
+					  pmu->irq_num, overflow);
+		WARN_ON(ret);
 	}
 }
 
+bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pmu *pmu = &vcpu->arch.pmu;
+	struct kvm_sync_regs *sregs = &vcpu->run->s.regs;
+	bool run_level = sregs->device_irq_level & KVM_ARM_DEV_PMU;
+
+	if (likely(irqchip_in_kernel(vcpu->kvm)))
+		return false;
+
+	return pmu->irq_level != run_level;
+}
+
+/*
+ * Reflect the PMU overflow interrupt output level into the kvm_run structure
+ */
+void kvm_pmu_update_run(struct kvm_vcpu *vcpu)
+{
+	struct kvm_sync_regs *regs = &vcpu->run->s.regs;
+
+	if (likely(irqchip_in_kernel(vcpu->kvm)))
+		return;
+
+	/* Populate the timer bitmap for user space */
+	regs->device_irq_level &= ~KVM_ARM_DEV_PMU;
+	if (vcpu->arch.pmu.irq_level)
+		regs->device_irq_level |= KVM_ARM_DEV_PMU;
+}
+
 /**
  * kvm_pmu_flush_hwstate - flush pmu state to cpu
  * @vcpu: The vcpu pointer