2 files changed, 53 insertions, 4 deletions

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 17e41e165f1a..179dcb0103fd 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -26,10 +26,40 @@
  *   Port from Qemu.
  */
 #include <linux/mm.h>
+#include <linux/bitops.h>
 #include "irq.h"
 
 #include <linux/kvm_host.h>
 
+static void pic_lock(struct kvm_pic *s)
+{
+        spin_lock(&s->lock);
+}
+
+static void pic_unlock(struct kvm_pic *s)
+{
+        struct kvm *kvm = s->kvm;
+        unsigned acks = s->pending_acks;
+        bool wakeup = s->wakeup_needed;
+        struct kvm_vcpu *vcpu;
+
+        s->pending_acks = 0;
+        s->wakeup_needed = false;
+
+        spin_unlock(&s->lock);
+
+        while (acks) {
+                kvm_notify_acked_irq(kvm, __ffs(acks));
+                acks &= acks - 1;
+        }
+
+        if (wakeup) {
+                vcpu = s->kvm->vcpus[0];
+                if (vcpu)
+                        kvm_vcpu_kick(vcpu);
+        }
+}
+
 static void pic_clear_isr(struct kvm_kpic_state *s, int irq)
 {
         s->isr &= ~(1 << irq);
@@ -136,17 +166,21 @@ static void pic_update_irq(struct kvm_pic *s)
 
 void kvm_pic_update_irq(struct kvm_pic *s)
 {
+        pic_lock(s);
         pic_update_irq(s);
+        pic_unlock(s);
 }
 
 void kvm_pic_set_irq(void *opaque, int irq, int level)
 {
         struct kvm_pic *s = opaque;
 
+        pic_lock(s);
         if (irq >= 0 && irq < PIC_NUM_PINS) {
                 pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);
                 pic_update_irq(s);
         }
+        pic_unlock(s);
 }
 
 /*
@@ -172,6 +206,7 @@ int kvm_pic_read_irq(struct kvm *kvm)
         int irq, irq2, intno;
         struct kvm_pic *s = pic_irqchip(kvm);
 
+        pic_lock(s);
         irq = pic_get_irq(&s->pics[0]);
         if (irq >= 0) {
                 pic_intack(&s->pics[0], irq);
@@ -196,6 +231,7 @@ int kvm_pic_read_irq(struct kvm *kvm)
                 intno = s->pics[0].irq_base + irq;
         }
         pic_update_irq(s);
+        pic_unlock(s);
         kvm_notify_acked_irq(kvm, irq);
 
         return intno;
@@ -203,7 +239,7 @@ int kvm_pic_read_irq(struct kvm *kvm)
 
 void kvm_pic_reset(struct kvm_kpic_state *s)
 {
-        int irq, irqbase;
+        int irq, irqbase, n;
         struct kvm *kvm = s->pics_state->irq_request_opaque;
         struct kvm_vcpu *vcpu0 = kvm->vcpus[0];
 
@@ -214,8 +250,10 @@ void kvm_pic_reset(struct kvm_kpic_state *s)
 
         for (irq = 0; irq < PIC_NUM_PINS/2; irq++) {
                 if (vcpu0 && kvm_apic_accept_pic_intr(vcpu0))
-                        if (s->irr & (1 << irq) || s->isr & (1 << irq))
-                                kvm_notify_acked_irq(kvm, irq+irqbase);
+                        if (s->irr & (1 << irq) || s->isr & (1 << irq)) {
+                                n = irq + irqbase;
+                                s->pics_state->pending_acks |= 1 << n;
+                        }
         }
         s->last_irr = 0;
         s->irr = 0;
@@ -406,6 +444,7 @@ static void picdev_write(struct kvm_io_device *this,
                         printk(KERN_ERR "PIC: non byte write\n");
                 return;
         }
+        pic_lock(s);
         switch (addr) {
         case 0x20:
         case 0x21:
@@ -418,6 +457,7 @@ static void picdev_write(struct kvm_io_device *this,
                 elcr_ioport_write(&s->pics[addr & 1], addr, data);
                 break;
         }
+        pic_unlock(s);
 }
 
 static void picdev_read(struct kvm_io_device *this,
@@ -431,6 +471,7 @@ static void picdev_read(struct kvm_io_device *this,
                         printk(KERN_ERR "PIC: non byte read\n");
                 return;
         }
+        pic_lock(s);
         switch (addr) {
         case 0x20:
         case 0x21:
@@ -444,6 +485,7 @@ static void picdev_read(struct kvm_io_device *this,
                 break;
         }
         *(unsigned char *)val = data;
+        pic_unlock(s);
 }
 
 /*
@@ -459,7 +501,7 @@ static void pic_irq_request(void *opaque, int level)
         s->output = level;
         if (vcpu && level && (s->pics[0].isr_ack & (1 << irq))) {
                 s->pics[0].isr_ack &= ~(1 << irq);
-                kvm_vcpu_kick(vcpu);
+                s->wakeup_needed = true;
         }
 }
 
@@ -469,6 +511,8 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm)
         s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL);
         if (!s)
                 return NULL;
+        spin_lock_init(&s->lock);
+        s->kvm = kvm;
         s->pics[0].elcr_mask = 0xf8;
         s->pics[1].elcr_mask = 0xde;
         s->irq_request = pic_irq_request;
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index b9e9051650ea..2bf32a03ceec 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -25,6 +25,7 @@
 #include <linux/mm_types.h>
 #include <linux/hrtimer.h>
 #include <linux/kvm_host.h>
+#include <linux/spinlock.h>
 
 #include "iodev.h"
 #include "ioapic.h"
@@ -59,6 +60,10 @@ struct kvm_kpic_state {
 };
 
 struct kvm_pic {
+        spinlock_t lock;
+        bool wakeup_needed;
+        unsigned pending_acks;
+        struct kvm *kvm;
         struct kvm_kpic_state pics[2]; /* 0 is master pic, 1 is slave pic */
         irq_request_func *irq_request;
         void *irq_request_opaque;