From 3217f7c25bca66eed9b07f0b8bfd1937169b0736 Mon Sep 17 00:00:00 2001
From: Christoffer Dall
Date: Thu, 27 Aug 2015 16:41:15 +0200
Subject: KVM: Add kvm_arch_vcpu_{un}blocking callbacks

Some times it is useful for architecture implementations of KVM to know
when the VCPU thread is about to block or when it comes back from
blocking (arm/arm64 needs to know this to properly implement timers, for
example).

Therefore provide a generic architecture callback function in line with
what we do elsewhere for KVM generic-arch interactions.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm64/include/asm/kvm_host.h | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'arch/arm64/include/asm')

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index ed039688c221..e4f4d65f7d2b 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -255,4 +255,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
 void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
 void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu);
 
+static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
+
 #endif /* __ARM64_KVM_HOST_H__ */
-- 
cgit v1.2.3-55-g7522


From d35268da66870d733ae763fd7f9b06a1f63f395e Mon Sep 17 00:00:00 2001
From: Christoffer Dall
Date: Tue, 25 Aug 2015 19:48:21 +0200
Subject: arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_block

We currently schedule a soft timer every time we exit the guest if the
timer did not expire while running the guest.  This is really not
necessary, because the only work we do in the timer work function is to
kick the vcpu.

Kicking the vcpu does two things:
(1) If the vpcu thread is on a waitqueue, make it runnable and remove it
from the waitqueue.
(2) If the vcpu is running on a different physical CPU from the one
doing the kick, it sends a reschedule IPI.

The second case cannot happen, because the soft timer is only ever
scheduled when the vcpu is not running.  The first case is only relevant
when the vcpu thread is on a waitqueue, which is only the case when the
vcpu thread has called kvm_vcpu_block().

Therefore, we only need to make sure a timer is scheduled for
kvm_vcpu_block(), which we do by encapsulating all calls to
kvm_vcpu_block() with kvm_timer_{un}schedule calls.

Additionally, we only schedule a soft timer if the timer is enabled and
unmasked, since it is useless otherwise.

Note that theoretically userspace can use the SET_ONE_REG interface to
change registers that should cause the timer to fire, even if the vcpu
is blocked without a scheduled timer, but this case was not supported
before this patch and we leave it for future work for now.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/include/asm/kvm_host.h   |  3 --
 arch/arm/kvm/arm.c                | 10 +++++
 arch/arm64/include/asm/kvm_host.h |  3 --
 include/kvm/arm_arch_timer.h      |  2 +
 virt/kvm/arm/arch_timer.c         | 94 +++++++++++++++++++++++++--------------
 5 files changed, 72 insertions(+), 40 deletions(-)

(limited to 'arch/arm64/include/asm')

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 84da97901f1f..c4072d9f32c7 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -234,7 +234,4 @@ static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {}
 
-static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
-static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
-
 #endif /* __ARM_KVM_HOST_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 78b286994577..7ed4d475d83a 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -271,6 +271,16 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 	return kvm_timer_should_fire(vcpu);
 }
 
+void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
+{
+	kvm_timer_schedule(vcpu);
+}
+
+void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
+{
+	kvm_timer_unschedule(vcpu);
+}
+
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 {
 	/* Force users to call KVM_ARM_VCPU_INIT */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index e4f4d65f7d2b..ed039688c221 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -255,7 +255,4 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
 void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
 void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu);
 
-static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
-static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
-
 #endif /* __ARM64_KVM_HOST_H__ */
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index e1e4d7c38dda..ef14cc1f1f26 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -71,5 +71,7 @@ u64 kvm_arm_timer_get_reg(struct kvm_vcpu *, u64 regid);
 int kvm_arm_timer_set_reg(struct kvm_vcpu *, u64 regid, u64 value);
 
 bool kvm_timer_should_fire(struct kvm_vcpu *vcpu);
+void kvm_timer_schedule(struct kvm_vcpu *vcpu);
+void kvm_timer_unschedule(struct kvm_vcpu *vcpu);
 
 #endif
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index b9d3a32cbc04..32095fbb5d7c 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -111,14 +111,21 @@ static enum hrtimer_restart kvm_timer_expire(struct hrtimer *hrt)
 	return HRTIMER_NORESTART;
 }
 
+static bool kvm_timer_irq_can_fire(struct kvm_vcpu *vcpu)
+{
+	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+
+	return !(timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) &&
+		(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE) &&
+		!kvm_vgic_get_phys_irq_active(timer->map);
+}
+
 bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
 {
 	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
 	cycle_t cval, now;
 
-	if ((timer->cntv_ctl & ARCH_TIMER_CTRL_IT_MASK) ||
-	    !(timer->cntv_ctl & ARCH_TIMER_CTRL_ENABLE) ||
-	    kvm_vgic_get_phys_irq_active(timer->map))
+	if (!kvm_timer_irq_can_fire(vcpu))
 		return false;
 
 	cval = timer->cntv_cval;
@@ -127,12 +134,57 @@ bool kvm_timer_should_fire(struct kvm_vcpu *vcpu)
 	return cval <= now;
 }
 
+/*
+ * Schedule the background timer before calling kvm_vcpu_block, so that this
+ * thread is removed from its waitqueue and made runnable when there's a timer
+ * interrupt to handle.
+ */
+void kvm_timer_schedule(struct kvm_vcpu *vcpu)
+{
+	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+	u64 ns;
+	cycle_t cval, now;
+
+	BUG_ON(timer_is_armed(timer));
+
+	/*
+	 * No need to schedule a background timer if the guest timer has
+	 * already expired, because kvm_vcpu_block will return before putting
+	 * the thread to sleep.
+	 */
+	if (kvm_timer_should_fire(vcpu))
+		return;
+
+	/*
+	 * If the timer is not capable of raising interrupts (disabled or
+	 * masked), then there's no more work for us to do.
+	 */
+	if (!kvm_timer_irq_can_fire(vcpu))
+		return;
+
+	/*  The timer has not yet expired, schedule a background timer */
+	cval = timer->cntv_cval;
+	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
+
+	ns = cyclecounter_cyc2ns(timecounter->cc,
+				 cval - now,
+				 timecounter->mask,
+				 &timecounter->frac);
+	timer_arm(timer, ns);
+}
+
+void kvm_timer_unschedule(struct kvm_vcpu *vcpu)
+{
+	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
+	timer_disarm(timer);
+}
+
 /**
  * kvm_timer_flush_hwstate - prepare to move the virt timer to the cpu
  * @vcpu: The vcpu pointer
  *
- * Disarm any pending soft timers, since the world-switch code will write the
- * virtual timer state back to the physical CPU.
+ * 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)
 {
@@ -140,17 +192,6 @@ void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
 	bool phys_active;
 	int ret;
 
-	/*
-	 * We're about to run this vcpu again, so there is no need to
-	 * keep the background timer running, as we're about to
-	 * populate the CPU timer again.
-	 */
-	timer_disarm(timer);
-
-	/*
-	 * If the timer expired while we were not scheduled, now is the time
-	 * to inject it.
-	 */
 	if (kvm_timer_should_fire(vcpu))
 		kvm_timer_inject_irq(vcpu);
 
@@ -176,32 +217,17 @@ void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
  * kvm_timer_sync_hwstate - sync timer state from cpu
  * @vcpu: The vcpu pointer
  *
- * Check if the virtual timer was armed and either schedule a corresponding
- * soft timer or inject directly if already expired.
+ * Check if the virtual timer has 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)
 {
 	struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
-	cycle_t cval, now;
-	u64 ns;
 
 	BUG_ON(timer_is_armed(timer));
 
-	if (kvm_timer_should_fire(vcpu)) {
-		/*
-		 * Timer has already expired while we were not
-		 * looking. Inject the interrupt and carry on.
-		 */
+	if (kvm_timer_should_fire(vcpu))
 		kvm_timer_inject_irq(vcpu);
-		return;
-	}
-
-	cval = timer->cntv_cval;
-	now = kvm_phys_timer_read() - vcpu->kvm->arch.timer.cntvoff;
-
-	ns = cyclecounter_cyc2ns(timecounter->cc, cval - now, timecounter->mask,
-				 &timecounter->frac);
-	timer_arm(timer, ns);
 }
 
 int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu,
-- 
cgit v1.2.3-55-g7522


From 3781528e3045e7c9cc7c4846e0f675b1f353655f Mon Sep 17 00:00:00 2001
From: Eric Auger
Date: Fri, 25 Sep 2015 23:41:14 +0200
Subject: KVM: arm/arm64: rename pause into power_off

The kvm_vcpu_arch pause field is renamed into power_off to prepare
for the introduction of a new pause field. Also vcpu_pause is renamed
into vcpu_sleep since we will sleep until both power_off and pause are
false.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/include/asm/kvm_host.h   |  4 ++--
 arch/arm/kvm/arm.c                | 20 ++++++++++----------
 arch/arm/kvm/psci.c               | 10 +++++-----
 arch/arm64/include/asm/kvm_host.h |  4 ++--
 4 files changed, 19 insertions(+), 19 deletions(-)

(limited to 'arch/arm64/include/asm')

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index c4072d9f32c7..107374f986fd 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -126,8 +126,8 @@ struct kvm_vcpu_arch {
 	 * here.
 	 */
 
-	/* Don't run the guest on this vcpu */
-	bool pause;
+	/* vcpu power-off state */
+	bool power_off;
 
 	/* IO related fields */
 	struct kvm_decode mmio_decode;
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 59125f48c707..9d2fb4772d8c 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -318,7 +318,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
 				    struct kvm_mp_state *mp_state)
 {
-	if (vcpu->arch.pause)
+	if (vcpu->arch.power_off)
 		mp_state->mp_state = KVM_MP_STATE_STOPPED;
 	else
 		mp_state->mp_state = KVM_MP_STATE_RUNNABLE;
@@ -331,10 +331,10 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 {
 	switch (mp_state->mp_state) {
 	case KVM_MP_STATE_RUNNABLE:
-		vcpu->arch.pause = false;
+		vcpu->arch.power_off = false;
 		break;
 	case KVM_MP_STATE_STOPPED:
-		vcpu->arch.pause = true;
+		vcpu->arch.power_off = true;
 		break;
 	default:
 		return -EINVAL;
@@ -478,11 +478,11 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
 	return vgic_initialized(kvm);
 }
 
-static void vcpu_pause(struct kvm_vcpu *vcpu)
+static void vcpu_sleep(struct kvm_vcpu *vcpu)
 {
 	wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
 
-	wait_event_interruptible(*wq, !vcpu->arch.pause);
+	wait_event_interruptible(*wq, !vcpu->arch.power_off);
 }
 
 static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -532,8 +532,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 		update_vttbr(vcpu->kvm);
 
-		if (vcpu->arch.pause)
-			vcpu_pause(vcpu);
+		if (vcpu->arch.power_off)
+			vcpu_sleep(vcpu);
 
 		/*
 		 * Disarming the background timer must be done in a
@@ -780,12 +780,12 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
 	vcpu_reset_hcr(vcpu);
 
 	/*
-	 * Handle the "start in power-off" case by marking the VCPU as paused.
+	 * Handle the "start in power-off" case.
 	 */
 	if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))
-		vcpu->arch.pause = true;
+		vcpu->arch.power_off = true;
 	else
-		vcpu->arch.pause = false;
+		vcpu->arch.power_off = false;
 
 	return 0;
 }
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index ad6f6424f1d1..0b556968a6da 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -63,7 +63,7 @@ static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu)
 
 static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.pause = true;
+	vcpu->arch.power_off = true;
 }
 
 static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
@@ -87,7 +87,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 	 */
 	if (!vcpu)
 		return PSCI_RET_INVALID_PARAMS;
-	if (!vcpu->arch.pause) {
+	if (!vcpu->arch.power_off) {
 		if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
 			return PSCI_RET_ALREADY_ON;
 		else
@@ -115,7 +115,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 	 * the general puspose registers are undefined upon CPU_ON.
 	 */
 	*vcpu_reg(vcpu, 0) = context_id;
-	vcpu->arch.pause = false;
+	vcpu->arch.power_off = false;
 	smp_mb();		/* Make sure the above is visible */
 
 	wq = kvm_arch_vcpu_wq(vcpu);
@@ -153,7 +153,7 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
 		mpidr = kvm_vcpu_get_mpidr_aff(tmp);
 		if ((mpidr & target_affinity_mask) == target_affinity) {
 			matching_cpus++;
-			if (!tmp->arch.pause)
+			if (!tmp->arch.power_off)
 				return PSCI_0_2_AFFINITY_LEVEL_ON;
 		}
 	}
@@ -179,7 +179,7 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
 	 * re-initialized.
 	 */
 	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
-		tmp->arch.pause = true;
+		tmp->arch.power_off = true;
 		kvm_vcpu_kick(tmp);
 	}
 
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index ed039688c221..4b4157b3b983 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -149,8 +149,8 @@ struct kvm_vcpu_arch {
 		u32	mdscr_el1;
 	} guest_debug_preserved;
 
-	/* Don't run the guest */
-	bool pause;
+	/* vcpu power-off state */
+	bool power_off;
 
 	/* IO related fields */
 	struct kvm_decode mmio_decode;
-- 
cgit v1.2.3-55-g7522


From 3b92830ad41b2fe377e0765322e8aefd0ab8388d Mon Sep 17 00:00:00 2001
From: Eric Auger
Date: Fri, 25 Sep 2015 23:41:17 +0200
Subject: KVM: arm/arm64: implement kvm_arm_[halt,resume]_guest

We introduce kvm_arm_halt_guest and resume functions. They
will be used for IRQ forward state change.

Halt is synchronous and prevents the guest from being re-entered.
We use the same mechanism put in place for PSCI former pause,
now renamed power_off. A new flag is introduced in arch vcpu state,
pause, only meant to be used by those functions.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/include/asm/kvm_host.h   |  3 +++
 arch/arm/kvm/arm.c                | 35 +++++++++++++++++++++++++++++++----
 arch/arm64/include/asm/kvm_host.h |  3 +++
 3 files changed, 37 insertions(+), 4 deletions(-)

(limited to 'arch/arm64/include/asm')

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 107374f986fd..6692982c9b57 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -129,6 +129,9 @@ struct kvm_vcpu_arch {
 	/* vcpu power-off state */
 	bool power_off;
 
+	 /* Don't run the guest (internal implementation need) */
+	bool pause;
+
 	/* IO related fields */
 	struct kvm_decode mmio_decode;
 
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 3b3384c37e24..ed1574724caf 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -353,7 +353,7 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
 	return ((!!v->arch.irq_lines || kvm_vgic_vcpu_pending_irq(v))
-		&& !v->arch.power_off);
+		&& !v->arch.power_off && !v->arch.pause);
 }
 
 /* Just ensure a guest exit from a particular CPU */
@@ -479,11 +479,38 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
 	return vgic_initialized(kvm);
 }
 
+static void kvm_arm_halt_guest(struct kvm *kvm) __maybe_unused;
+static void kvm_arm_resume_guest(struct kvm *kvm) __maybe_unused;
+
+static void kvm_arm_halt_guest(struct kvm *kvm)
+{
+	int i;
+	struct kvm_vcpu *vcpu;
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		vcpu->arch.pause = true;
+	force_vm_exit(cpu_all_mask);
+}
+
+static void kvm_arm_resume_guest(struct kvm *kvm)
+{
+	int i;
+	struct kvm_vcpu *vcpu;
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+
+		vcpu->arch.pause = false;
+		wake_up_interruptible(wq);
+	}
+}
+
 static void vcpu_sleep(struct kvm_vcpu *vcpu)
 {
 	wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
 
-	wait_event_interruptible(*wq, !vcpu->arch.power_off);
+	wait_event_interruptible(*wq, ((!vcpu->arch.power_off) &&
+				       (!vcpu->arch.pause)));
 }
 
 static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -533,7 +560,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 		update_vttbr(vcpu->kvm);
 
-		if (vcpu->arch.power_off)
+		if (vcpu->arch.power_off || vcpu->arch.pause)
 			vcpu_sleep(vcpu);
 
 		/*
@@ -561,7 +588,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		}
 
 		if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) ||
-			vcpu->arch.power_off) {
+			vcpu->arch.power_off || vcpu->arch.pause) {
 			local_irq_enable();
 			kvm_timer_sync_hwstate(vcpu);
 			kvm_vgic_sync_hwstate(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4b4157b3b983..a35ce7266aac 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -152,6 +152,9 @@ struct kvm_vcpu_arch {
 	/* vcpu power-off state */
 	bool power_off;
 
+	/* Don't run the guest (internal implementation need) */
+	bool pause;
+
 	/* IO related fields */
 	struct kvm_decode mmio_decode;
 
-- 
cgit v1.2.3-55-g7522


From b5905dc12ed4254f7e0aac62bab48f002181f639 Mon Sep 17 00:00:00 2001
From: Christoffer Dall
Date: Sun, 30 Aug 2015 15:55:22 +0200
Subject: arm/arm64: KVM: Improve kvm_exit tracepoint

The ARM architecture only saves the exit class to the HSR (ESR_EL2 for
arm64) on synchronous exceptions, not on asynchronous exceptions like an
IRQ.  However, we only report the exception class on kvm_exit, which is
confusing because an IRQ looks like it exited at some PC with the same
reason as the previous exit.  Add a lookup table for the exception index
and prepend the kvm_exit tracepoint text with the exception type to
clarify this situation.

Also resolve the exception class (EC) to a human-friendly text version
so the trace output becomes immediately usable for debugging this code.

Cc: Wei Huang <wei@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/include/asm/kvm_arm.h   | 20 ++++++++++++++++++++
 arch/arm/kvm/arm.c               |  2 +-
 arch/arm/kvm/trace.h             | 10 +++++++---
 arch/arm64/include/asm/kvm_arm.h | 16 ++++++++++++++++
 4 files changed, 44 insertions(+), 4 deletions(-)

(limited to 'arch/arm64/include/asm')

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index d995821f1698..dc641ddf0784 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -218,4 +218,24 @@
 #define HSR_DABT_CM		(1U << 8)
 #define HSR_DABT_EA		(1U << 9)
 
+#define kvm_arm_exception_type	\
+	{0, "RESET" }, 		\
+	{1, "UNDEFINED" },	\
+	{2, "SOFTWARE" },	\
+	{3, "PREF_ABORT" },	\
+	{4, "DATA_ABORT" },	\
+	{5, "IRQ" },		\
+	{6, "FIQ" },		\
+	{7, "HVC" }
+
+#define HSRECN(x) { HSR_EC_##x, #x }
+
+#define kvm_arm_exception_class \
+	HSRECN(UNKNOWN), HSRECN(WFI), HSRECN(CP15_32), HSRECN(CP15_64), \
+	HSRECN(CP14_MR), HSRECN(CP14_LS), HSRECN(CP_0_13), HSRECN(CP10_ID), \
+	HSRECN(JAZELLE), HSRECN(BXJ), HSRECN(CP14_64), HSRECN(SVC_HYP), \
+	HSRECN(HVC), HSRECN(SMC), HSRECN(IABT), HSRECN(IABT_HYP), \
+	HSRECN(DABT), HSRECN(DABT_HYP)
+
+
 #endif /* __ARM_KVM_ARM_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index ed1574724caf..eab83b2435b8 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -635,7 +635,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		 * guest time.
 		 */
 		kvm_guest_exit();
-		trace_kvm_exit(kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
+		trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
 
 		/*
 		 * We must sync the timer state before the vgic state so that
diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h
index 0ec35392d208..c25a88598eb0 100644
--- a/arch/arm/kvm/trace.h
+++ b/arch/arm/kvm/trace.h
@@ -25,21 +25,25 @@ TRACE_EVENT(kvm_entry,
 );
 
 TRACE_EVENT(kvm_exit,
-	TP_PROTO(unsigned int exit_reason, unsigned long vcpu_pc),
-	TP_ARGS(exit_reason, vcpu_pc),
+	TP_PROTO(int idx, unsigned int exit_reason, unsigned long vcpu_pc),
+	TP_ARGS(idx, exit_reason, vcpu_pc),
 
 	TP_STRUCT__entry(
+		__field(	int,		idx		)
 		__field(	unsigned int,	exit_reason	)
 		__field(	unsigned long,	vcpu_pc		)
 	),
 
 	TP_fast_assign(
+		__entry->idx			= idx;
 		__entry->exit_reason		= exit_reason;
 		__entry->vcpu_pc		= vcpu_pc;
 	),
 
-	TP_printk("HSR_EC: 0x%04x, PC: 0x%08lx",
+	TP_printk("%s: HSR_EC: 0x%04x (%s), PC: 0x%08lx",
+		  __print_symbolic(__entry->idx, kvm_arm_exception_type),
 		  __entry->exit_reason,
+		  __print_symbolic(__entry->exit_reason, kvm_arm_exception_class),
 		  __entry->vcpu_pc)
 );
 
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 9694f2654593..5e6857b6bdc4 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -200,4 +200,20 @@
 /* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
 #define HPFAR_MASK	(~UL(0xf))
 
+#define kvm_arm_exception_type	\
+	{0, "IRQ" }, 		\
+	{1, "TRAP" }
+
+#define ECN(x) { ESR_ELx_EC_##x, #x }
+
+#define kvm_arm_exception_class \
+	ECN(UNKNOWN), ECN(WFx), ECN(CP15_32), ECN(CP15_64), ECN(CP14_MR), \
+	ECN(CP14_LS), ECN(FP_ASIMD), ECN(CP10_ID), ECN(CP14_64), ECN(SVC64), \
+	ECN(HVC64), ECN(SMC64), ECN(SYS64), ECN(IMP_DEF), ECN(IABT_LOW), \
+	ECN(IABT_CUR), ECN(PC_ALIGN), ECN(DABT_LOW), ECN(DABT_CUR), \
+	ECN(SP_ALIGN), ECN(FP_EXC32), ECN(FP_EXC64), ECN(SERROR), \
+	ECN(BREAKPT_LOW), ECN(BREAKPT_CUR), ECN(SOFTSTP_LOW), \
+	ECN(SOFTSTP_CUR), ECN(WATCHPT_LOW), ECN(WATCHPT_CUR), \
+	ECN(BKPT32), ECN(VECTOR32), ECN(BRK64)
+
 #endif /* __ARM64_KVM_ARM_H__ */
-- 
cgit v1.2.3-55-g7522