kvm: Make kvm_state globally available

KVM-assisted devices need access to it but we have no clean channel to
distribute a reference. As a workaround until there is a better
solution, export kvm_state for global use, though use should remain
restricted to the mentioned scenario.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/kvm.h b/kvm.h
index 4caa6ec..59b2c29 100644
--- a/kvm.h
+++ b/kvm.h
@@ -85,6 +85,7 @@
 
 struct KVMState;
 typedef struct KVMState KVMState;
+extern KVMState *kvm_state;
 
 int kvm_ioctl(KVMState *s, int type, ...);