[3/5] Remove references to VCPU in i8254

Commit Message

Chris Lalancette Oct. 27, 2009, 4:41 p.m. UTC

None

Patch

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index fab7440..d5c08fa 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -33,6 +33,7 @@ 
 
 #include "irq.h"
 #include "i8254.h"
+#include "kvm_timer.h"
 
 #ifndef CONFIG_X86_64
 #define mod_64(x, y) ((x) - (y) * div64_u64(x, y))
@@ -227,12 +228,13 @@  static void pit_latch_status(struct kvm *kvm, int channel)
 	}
 }
 
-int pit_has_pending_timer(struct kvm_vcpu *vcpu)
+int pit_has_pending_timer(struct kvm *kvm)
 {
-	struct kvm_pit *pit = vcpu->kvm->arch.vpit;
+	struct kvm_pit *pit = kvm->arch.vpit;
 
-	if (pit && kvm_vcpu_is_bsp(vcpu) && pit->pit_state.irq_ack)
+	if (pit && pit->pit_state.irq_ack)
 		return atomic_read(&pit->pit_state.pit_timer.pending);
+
 	return 0;
 }
 
@@ -252,6 +254,13 @@  void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
 	struct kvm_pit *pit = vcpu->kvm->arch.vpit;
 	struct hrtimer *timer;
 
+	/*
+	 * technically, the PIT isn't hooked to a particular VCPU;
+	 * the logical structure is PIT -> [IOA]PIC -> CPU[s].  However,
+	 * hrtimers expire on a per-cpu basis, and since we initially
+	 * created the hrtimer during BSP creation, we move it around
+	 * with the BSP.
+	 */
 	if (!kvm_vcpu_is_bsp(vcpu) || !pit)
 		return;
 
@@ -277,6 +286,33 @@  static struct kvm_timer_ops kpit_ops = {
 	.is_periodic = kpit_is_periodic,
 };
 
+static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
+{
+	struct kvm_timer *ktimer = container_of(data, struct kvm_timer, timer);
+	int restart_timer = 0;
+
+	/*
+	 * There is a race window between reading and incrementing, but we do
+	 * not care about potentially losing timer events in the !reinject
+	 * case anyway.
+	 */
+	if (ktimer->reinject || !atomic_read(&ktimer->pending))
+		atomic_inc(&ktimer->pending);
+
+	if (waitqueue_active(&ktimer->kvm->bsp_vcpu->wq))
+		wake_up_interruptible(&ktimer->kvm->bsp_vcpu->wq);
+
+	if (ktimer->t_ops->is_periodic(ktimer)) {
+		hrtimer_add_expires_ns(&ktimer->timer, ktimer->period);
+		restart_timer = 1;
+	}
+
+	if (restart_timer)
+		return HRTIMER_RESTART;
+	else
+		return HRTIMER_NORESTART;
+}
+
 static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
 {
 	struct kvm_timer *pt = &ps->pit_timer;
@@ -291,10 +327,9 @@  static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
 	pt->period = interval;
 	ps->is_periodic = is_period;
 
-	pt->timer.function = kvm_timer_fn;
+	pt->timer.function = pit_timer_fn;
 	pt->t_ops = &kpit_ops;
 	pt->kvm = ps->pit->kvm;
-	pt->vcpu = pt->kvm->bsp_vcpu;
 
 	atomic_set(&pt->pending, 0);
 	ps->irq_ack = 1;
@@ -705,10 +740,9 @@  static void __inject_pit_timer_intr(struct kvm *kvm)
 			kvm_apic_nmi_wd_deliver(vcpu);
 }
 
-void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu)
+void kvm_inject_pit_timer_irqs(struct kvm *kvm)
 {
-	struct kvm_pit *pit = vcpu->kvm->arch.vpit;
-	struct kvm *kvm = vcpu->kvm;
+	struct kvm_pit *pit = kvm->arch.vpit;
 	struct kvm_kpit_state *ps;
 
 	if (pit) {
diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
index d4c1c7f..d7bc40b 100644
--- a/arch/x86/kvm/i8254.h
+++ b/arch/x86/kvm/i8254.h
@@ -49,10 +49,12 @@  struct kvm_pit {
 #define KVM_MAX_PIT_INTR_INTERVAL   HZ / 100
 #define KVM_PIT_CHANNEL_MASK	    0x3
 
-void kvm_inject_pit_timer_irqs(struct kvm_vcpu *vcpu);
+int pit_has_pending_timer(struct kvm *kvm);
+void kvm_inject_pit_timer_irqs(struct kvm *kvm);
 void kvm_pit_load_count(struct kvm *kvm, int channel, u32 val, int hpet_legacy_start);
 struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags);
 void kvm_free_pit(struct kvm *kvm);
 void kvm_pit_reset(struct kvm_pit *pit);
+void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu);
 
 #endif
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 96dfbb6..ab3a56e 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -34,7 +34,7 @@  int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 {
 	int ret;
 
-	ret = pit_has_pending_timer(vcpu);
+	ret = pit_has_pending_timer(vcpu->kvm);
 	ret |= apic_has_pending_timer(vcpu);
 
 	return ret;
@@ -89,7 +89,7 @@  EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
 {
 	kvm_inject_apic_timer_irqs(vcpu);
-	kvm_inject_pit_timer_irqs(vcpu);
+	kvm_inject_pit_timer_irqs(vcpu->kvm);
 	/* TODO: PIT, RTC etc. */
 }
 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index c025a23..e16b968 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -95,10 +95,8 @@  void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu);
 void kvm_inject_apic_timer_irqs(struct kvm_vcpu *vcpu);
 void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu);
 void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu);
-void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu);
 void __kvm_migrate_timers(struct kvm_vcpu *vcpu);
 
-int pit_has_pending_timer(struct kvm_vcpu *vcpu);
 int apic_has_pending_timer(struct kvm_vcpu *vcpu);
 
 #endif
diff --git a/arch/x86/kvm/kvm_timer.h b/arch/x86/kvm/kvm_timer.h
index 55c7524..ba39e25 100644
--- a/arch/x86/kvm/kvm_timer.h
+++ b/arch/x86/kvm/kvm_timer.h
@@ -1,3 +1,5 @@ 
+#ifndef __KVM_TIMER_H
+#define __KVM_TIMER_H
 
 struct kvm_timer {
 	struct hrtimer timer;
@@ -16,3 +18,4 @@  struct kvm_timer_ops {
 
 enum hrtimer_restart kvm_timer_fn(struct hrtimer *data);
 
+#endif