diff --git a/hw/vmport.c b/hw/vmport.c
index 884af3f..9dc94a3 100644
--- a/hw/vmport.c
+++ b/hw/vmport.c
@@ -25,6 +25,7 @@
 #include "isa.h"
 #include "pc.h"
 #include "sysemu.h"
+#include "kvm.h"
 
 //#define VMPORT_DEBUG
 
@@ -57,6 +58,9 @@ static uint32_t vmport_ioport_read(void *opaque, uint32_t addr)
     CPUState *env = cpu_single_env;
     unsigned char command;
     uint32_t eax;
+    uint32_t result;
+
+    cpu_synchronize_state(env, 0);
 
     eax = env->regs[R_EAX];
     if (eax != VMPORT_MAGIC)
@@ -73,14 +77,19 @@ static uint32_t vmport_ioport_read(void *opaque, uint32_t addr)
         return eax;
     }
 
-    return s->func[command](s->opaque[command], addr);
+    result = s->func[command](s->opaque[command], addr);
+    cpu_synchronize_state(env, 1);
+
+    return result;
 }
 
 static void vmport_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 {
     CPUState *env = cpu_single_env;
 
+    cpu_synchronize_state(env, 0);
     env->regs[R_EAX] = vmport_ioport_read(opaque, addr);
+    cpu_synchronize_state(env, 1);
 }
 
 static uint32_t vmport_cmd_get_version(void *opaque, uint32_t addr)