9 files changed, 88 insertions, 34 deletions

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 9c77e3939e97..076b00d1dbff 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -182,7 +182,7 @@ int kvm_dev_ioctl_check_extension(long ext)
         switch (ext) {
         case KVM_CAP_IRQCHIP:
         case KVM_CAP_MP_STATE:
-
+        case KVM_CAP_IRQ_INJECT_STATUS:
                 r = 1;
                 break;
         case KVM_CAP_COALESCED_MMIO:
@@ -927,6 +927,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
                         goto out;
                 }
                 break;
+        case KVM_IRQ_LINE_STATUS:
         case KVM_IRQ_LINE: {
                 struct kvm_irq_level irq_event;
 
@@ -934,10 +935,17 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 if (copy_from_user(&irq_event, argp, sizeof irq_event))
                         goto out;
                 if (irqchip_in_kernel(kvm)) {
+                        __s32 status;
                         mutex_lock(&kvm->lock);
-                        kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
+                        status = kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
                                     irq_event.irq, irq_event.level);
                         mutex_unlock(&kvm->lock);
+                        if (ioctl == KVM_IRQ_LINE_STATUS) {
+                                irq_event.status = status;
+                                if (copy_to_user(argp, &irq_event,
+                                                        sizeof irq_event))
+                                        goto out;
+                        }
                         r = 0;
                 }
                 break;
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 55fd4c5fd388..f0faf58044ff 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -616,7 +616,7 @@ void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);
 void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long cr2,
                            u32 error_code);
 
-void kvm_pic_set_irq(void *opaque, int irq, int level);
+int kvm_pic_set_irq(void *opaque, int irq, int level);
 
 void kvm_inject_nmi(struct kvm_vcpu *vcpu);
 
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 93160375c841..b4e662e94ddc 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -77,12 +77,13 @@ void kvm_pic_clear_isr_ack(struct kvm *kvm)
 /*
  * set irq level. If an edge is detected, then the IRR is set to 1
  */
-static inline void pic_set_irq1(struct kvm_kpic_state *s, int irq, int level)
+static inline int pic_set_irq1(struct kvm_kpic_state *s, int irq, int level)
 {
-        int mask;
+        int mask, ret = 1;
         mask = 1 << irq;
         if (s->elcr & mask)     /* level triggered */
                 if (level) {
+                        ret = !(s->irr & mask);
                         s->irr |= mask;
                         s->last_irr |= mask;
                 } else {
@@ -91,11 +92,15 @@ static inline void pic_set_irq1(struct kvm_kpic_state *s, int irq, int level)
                 }
         else    /* edge triggered */
                 if (level) {
-                        if ((s->last_irr & mask) == 0)
+                        if ((s->last_irr & mask) == 0) {
+                                ret = !(s->irr & mask);
                                 s->irr |= mask;
+                        }
                         s->last_irr |= mask;
                 } else
                         s->last_irr &= ~mask;
+
+        return (s->imr & mask) ? -1 : ret;
 }
 
 /*
@@ -172,16 +177,19 @@ void kvm_pic_update_irq(struct kvm_pic *s)
         pic_unlock(s);
 }
 
-void kvm_pic_set_irq(void *opaque, int irq, int level)
+int kvm_pic_set_irq(void *opaque, int irq, int level)
 {
         struct kvm_pic *s = opaque;
+        int ret = -1;
 
         pic_lock(s);
         if (irq >= 0 && irq < PIC_NUM_PINS) {
-                pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);
+                ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);
                 pic_update_irq(s);
         }
         pic_unlock(s);
+
+        return ret;
 }
 
 /*
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 05d7be89b5eb..e4db5be7c953 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1019,6 +1019,7 @@ int kvm_dev_ioctl_check_extension(long ext)
         case KVM_CAP_MP_STATE:
         case KVM_CAP_SYNC_MMU:
         case KVM_CAP_REINJECT_CONTROL:
+        case KVM_CAP_IRQ_INJECT_STATUS:
                 r = 1;
                 break;
         case KVM_CAP_COALESCED_MMIO:
@@ -1877,6 +1878,7 @@ long kvm_arch_vm_ioctl(struct file *filp,
         create_pit_unlock:
                 mutex_unlock(&kvm->lock);
                 break;
+        case KVM_IRQ_LINE_STATUS:
         case KVM_IRQ_LINE: {
                 struct kvm_irq_level irq_event;
 
@@ -1884,10 +1886,17 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 if (copy_from_user(&irq_event, argp, sizeof irq_event))
                         goto out;
                 if (irqchip_in_kernel(kvm)) {
+                        __s32 status;
                         mutex_lock(&kvm->lock);
-                        kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
-                                    irq_event.irq, irq_event.level);
+                        status = kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
+                                        irq_event.irq, irq_event.level);
                         mutex_unlock(&kvm->lock);
+                        if (ioctl == KVM_IRQ_LINE_STATUS) {
+                                irq_event.status = status;
+                                if (copy_to_user(argp, &irq_event,
+                                                        sizeof irq_event))
+                                        goto out;
+                        }
                         r = 0;
                 }
                 break;
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 2163b3dd36e7..dd48225d1824 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -48,7 +48,10 @@ struct kvm_irq_level {
          * For IA-64 (APIC model) IOAPIC0: irq 0-23; IOAPIC1: irq 24-47..
          * For X86 (standard AT mode) PIC0/1: irq 0-15. IOAPIC0: 0-23..
          */
-        __u32 irq;
+        union {
+                __u32 irq;
+                __s32 status;
+        };
         __u32 level;
 };
 
@@ -402,6 +405,7 @@ struct kvm_trace_rec {
 #ifdef __KVM_HAVE_IOAPIC
 #define KVM_CAP_IRQ_ROUTING 25
 #endif
+#define KVM_CAP_IRQ_INJECT_STATUS 26
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -465,6 +469,7 @@ struct kvm_irq_routing {
 #define KVM_CREATE_PIT            _IO(KVMIO,  0x64)
 #define KVM_GET_PIT               _IOWR(KVMIO, 0x65, struct kvm_pit_state)
 #define KVM_SET_PIT               _IOR(KVMIO,  0x66, struct kvm_pit_state)
+#define KVM_IRQ_LINE_STATUS       _IOWR(KVMIO, 0x67, struct kvm_irq_level)
 #define KVM_REGISTER_COALESCED_MMIO \
                         _IOW(KVMIO,  0x67, struct kvm_coalesced_mmio_zone)
 #define KVM_UNREGISTER_COALESCED_MMIO \
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 18b4df8264cf..894a56e365e8 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -110,7 +110,7 @@ struct kvm_memory_slot {
 
 struct kvm_kernel_irq_routing_entry {
         u32 gsi;
-        void (*set)(struct kvm_kernel_irq_routing_entry *e,
+        int (*set)(struct kvm_kernel_irq_routing_entry *e,
                     struct kvm *kvm, int level);
         union {
                 struct {
@@ -352,7 +352,7 @@ void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
                                       struct kvm_irq_mask_notifier *kimn);
 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask);
 
-void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level);
+int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level);
 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);
 void kvm_register_irq_ack_notifier(struct kvm *kvm,
                                    struct kvm_irq_ack_notifier *kian);
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 1c986ac59ad6..c3b99def9cbc 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -83,19 +83,22 @@ static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
         return result;
 }
 
-static void ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
+static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
 {
         union ioapic_redir_entry *pent;
+        int injected = -1;
 
         pent = &ioapic->redirtbl[idx];
 
         if (!pent->fields.mask) {
-                int injected = ioapic_deliver(ioapic, idx);
+                injected = ioapic_deliver(ioapic, idx);
                 if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG)
                         pent->fields.remote_irr = 1;
         }
         if (!pent->fields.trig_mode)
                 ioapic->irr &= ~(1 << idx);
+
+        return injected;
 }
 
 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
@@ -207,7 +210,7 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
         u8 trig_mode = ioapic->redirtbl[irq].fields.trig_mode;
         u32 deliver_bitmask;
         struct kvm_vcpu *vcpu;
-        int vcpu_id, r = 0;
+        int vcpu_id, r = -1;
 
         ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
                      "vector=%x trig_mode=%x\n",
@@ -247,7 +250,9 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
                         deliver_bitmask &= ~(1 << vcpu_id);
                         vcpu = ioapic->kvm->vcpus[vcpu_id];
                         if (vcpu) {
-                                r = ioapic_inj_irq(ioapic, vcpu, vector,
+                                if (r < 0)
+                                        r = 0;
+                                r += ioapic_inj_irq(ioapic, vcpu, vector,
                                                trig_mode, delivery_mode);
                         }
                 }
@@ -258,8 +263,10 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
                                 continue;
                         deliver_bitmask &= ~(1 << vcpu_id);
                         vcpu = ioapic->kvm->vcpus[vcpu_id];
-                        if (vcpu)
+                        if (vcpu) {
                                 ioapic_inj_nmi(vcpu);
+                                r = 1;
+                        }
                         else
                                 ioapic_debug("NMI to vcpu %d failed\n",
                                                 vcpu->vcpu_id);
@@ -273,11 +280,12 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
         return r;
 }
 
-void kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
+int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
 {
         u32 old_irr = ioapic->irr;
         u32 mask = 1 << irq;
         union ioapic_redir_entry entry;
+        int ret = 1;
 
         if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
                 entry = ioapic->redirtbl[irq];
@@ -288,9 +296,10 @@ void kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
                         ioapic->irr |= mask;
                         if ((!entry.fields.trig_mode && old_irr != ioapic->irr)
                             || !entry.fields.remote_irr)
-                                ioapic_service(ioapic, irq);
+                                ret = ioapic_service(ioapic, irq);
                 }
         }
+        return ret;
 }
 
 static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int pin,
diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
index 49c9581d2586..a34bd5e6436b 100644
--- a/virt/kvm/ioapic.h
+++ b/virt/kvm/ioapic.h
@@ -83,7 +83,7 @@ struct kvm_vcpu *kvm_get_lowest_prio_vcpu(struct kvm *kvm, u8 vector,
                                        unsigned long bitmap);
 void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode);
 int kvm_ioapic_init(struct kvm *kvm);
-void kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level);
+int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level);
 void kvm_ioapic_reset(struct kvm_ioapic *ioapic);
 u32 kvm_ioapic_get_delivery_bitmask(struct kvm_ioapic *ioapic, u8 dest,
                                 u8 dest_mode);
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 6bc7439eff6e..be8aba791554 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -29,22 +29,24 @@
 
 #include "ioapic.h"
 
-static void kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
-                            struct kvm *kvm, int level)
+static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
+                           struct kvm *kvm, int level)
 {
 #ifdef CONFIG_X86
-        kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
+        return kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
+#else
+        return -1;
 #endif
 }
 
-static void kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
-                               struct kvm *kvm, int level)
+static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
+                              struct kvm *kvm, int level)
 {
-        kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
+        return kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
 }
 
-static void kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
-                        struct kvm *kvm, int level)
+static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
+                       struct kvm *kvm, int level)
 {
         int vcpu_id;
         struct kvm_vcpu *vcpu;
@@ -88,13 +90,20 @@ static void kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
         default:
                 break;
         }
+        return 1;
 }
 
-/* This should be called with the kvm->lock mutex held */
-void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
+/* This should be called with the kvm->lock mutex held
+ * Return value:
+ *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
+ *  = 0   Interrupt was coalesced (previous irq is still pending)
+ *  > 0   Number of CPUs interrupt was delivered to
+ */
+int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
 {
         struct kvm_kernel_irq_routing_entry *e;
         unsigned long *irq_state, sig_level;
+        int ret = -1;
 
         if (irq < KVM_IOAPIC_NUM_PINS) {
                 irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
@@ -113,8 +122,14 @@ void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
          * writes to the unused one.
          */
         list_for_each_entry(e, &kvm->irq_routing, link)
-                if (e->gsi == irq)
-                        e->set(e, kvm, sig_level);
+                if (e->gsi == irq) {
+                        int r = e->set(e, kvm, sig_level);
+                        if (r < 0)
+                                continue;
+
+                        ret = r + ((ret < 0) ? 0 : ret);
+                }
+        return ret;
 }
 
 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
@@ -232,7 +247,7 @@ int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
                         e->set = kvm_set_pic_irq;
                         break;
                 case KVM_IRQCHIP_PIC_SLAVE:
-                                e->set = kvm_set_pic_irq;
+                        e->set = kvm_set_pic_irq;
                         delta = 8;
                         break;
                 case KVM_IRQCHIP_IOAPIC: