hyperv: process SIGNAL_EVENT hypercall

Add handling of SIGNAL_EVENT hypercall.  For that, provide an interface
to associate an EventNotifier with an event connection number, so that
it's signaled when the SIGNAL_EVENT hypercall with the matching
connection ID is called by the guest.

Support for using KVM functionality for this will be added in a followup
patch.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Message-Id: <20180921082217.29481-8-rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/target/i386/hyperv.c b/target/i386/hyperv.c
index 3f76c3e266..96b3b5ad7f 100644
--- a/target/i386/hyperv.c
+++ b/target/i386/hyperv.c
@@ -79,16 +79,18 @@ int kvm_hv_handle_exit(X86CPU *cpu, struct kvm_hyperv_exit *exit)
 
         return 0;
     case KVM_EXIT_HYPERV_HCALL: {
-        uint16_t code;
+        uint16_t code = exit->u.hcall.input & 0xffff;
+        bool fast = exit->u.hcall.input & HV_HYPERCALL_FAST;
+        uint64_t param = exit->u.hcall.params[0];
 
-        code  = exit->u.hcall.input & 0xffff;
         switch (code) {
-        case HV_POST_MESSAGE:
         case HV_SIGNAL_EVENT:
+            exit->u.hcall.result = hyperv_hcall_signal_event(param, fast);
+            break;
         default:
             exit->u.hcall.result = HV_STATUS_INVALID_HYPERCALL_CODE;
-            return 0;
         }
+        return 0;
     }
     default:
         return -1;