KVM: Report IRQ injection status to userspace.

IRQ injection status is either -1 (if there was no CPU found
that should except the interrupt because IRQ was masked or
ioapic was misconfigured or ...) or >= 0 in that case the
number indicates to how many CPUs interrupt was injected.
If the value is 0 it means that the interrupt was coalesced
and probably should be reinjected.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 10 insertions, 2 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;