diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index e30cf0a2a1..57c95786f6 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -16,11 +16,8 @@
 #include "exec/ram_addr.h"
 #include "exec/confidential-guest-support.h"
 #include "hw/boards.h"
-#include "hw/s390x/s390-virtio-hcall.h"
 #include "hw/s390x/sclp.h"
 #include "hw/s390x/s390_flic.h"
-#include "hw/s390x/ioinst.h"
-#include "hw/s390x/css.h"
 #include "virtio-ccw.h"
 #include "qemu/config-file.h"
 #include "qemu/ctype.h"
@@ -124,58 +121,6 @@ static void subsystem_reset(void)
     }
 }
 
-static int virtio_ccw_hcall_notify(const uint64_t *args)
-{
-    uint64_t subch_id = args[0];
-    uint64_t data = args[1];
-    SubchDev *sch;
-    VirtIODevice *vdev;
-    int cssid, ssid, schid, m;
-    uint16_t vq_idx = data;
-
-    if (ioinst_disassemble_sch_ident(subch_id, &m, &cssid, &ssid, &schid)) {
-        return -EINVAL;
-    }
-    sch = css_find_subch(m, cssid, ssid, schid);
-    if (!sch || !css_subch_visible(sch)) {
-        return -EINVAL;
-    }
-
-    vdev = virtio_ccw_get_vdev(sch);
-    if (vq_idx >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, vq_idx)) {
-        return -EINVAL;
-    }
-
-    if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFICATION_DATA)) {
-        virtio_queue_set_shadow_avail_idx(virtio_get_queue(vdev, vq_idx),
-                                          (data >> 16) & 0xFFFF);
-    }
-
-    virtio_queue_notify(vdev, vq_idx);
-    return 0;
-}
-
-static int virtio_ccw_hcall_early_printk(const uint64_t *args)
-{
-    uint64_t mem = args[0];
-    MachineState *ms = MACHINE(qdev_get_machine());
-
-    if (mem < ms->ram_size) {
-        /* Early printk */
-        return 0;
-    }
-    return -EINVAL;
-}
-
-static void virtio_ccw_register_hcalls(void)
-{
-    s390_register_virtio_hypercall(KVM_S390_VIRTIO_CCW_NOTIFY,
-                                   virtio_ccw_hcall_notify);
-    /* Tolerate early printk. */
-    s390_register_virtio_hypercall(KVM_S390_VIRTIO_NOTIFY,
-                                   virtio_ccw_hcall_early_printk);
-}
-
 static void s390_memory_init(MemoryRegion *ram)
 {
     MemoryRegion *sysmem = get_system_memory();
@@ -302,9 +247,6 @@ static void ccw_init(MachineState *machine)
                               OBJECT(dev));
     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
 
-    /* register hypercalls */
-    virtio_ccw_register_hcalls();
-
     s390_enable_css_support(s390_cpu_addr2state(0));
 
     ret = css_create_css_image(VIRTUAL_CSSID, true);
diff --git a/hw/s390x/s390-virtio-hcall.c b/hw/s390x/s390-virtio-hcall.c
index ec7cf8beb3..ca49e3cd22 100644
--- a/hw/s390x/s390-virtio-hcall.c
+++ b/hw/s390x/s390-virtio-hcall.c
@@ -11,31 +11,64 @@
 
 #include "qemu/osdep.h"
 #include "cpu.h"
+#include "hw/boards.h"
 #include "hw/s390x/s390-virtio-hcall.h"
+#include "hw/s390x/ioinst.h"
+#include "hw/s390x/css.h"
+#include "virtio-ccw.h"
 
-#define MAX_DIAG_SUBCODES 255
+static int handle_virtio_notify(uint64_t mem)
+{
+    MachineState *ms = MACHINE(qdev_get_machine());
 
-static s390_virtio_fn s390_diag500_table[MAX_DIAG_SUBCODES];
+    if (mem < ms->ram_size) {
+        /* Early printk */
+        return 0;
+    }
+    return -EINVAL;
+}
 
-void s390_register_virtio_hypercall(uint64_t code, s390_virtio_fn fn)
+static int handle_virtio_ccw_notify(uint64_t subch_id, uint64_t data)
 {
-    assert(code < MAX_DIAG_SUBCODES);
-    assert(!s390_diag500_table[code]);
+    SubchDev *sch;
+    VirtIODevice *vdev;
+    int cssid, ssid, schid, m;
+    uint16_t vq_idx = data;
+
+    if (ioinst_disassemble_sch_ident(subch_id, &m, &cssid, &ssid, &schid)) {
+        return -EINVAL;
+    }
+    sch = css_find_subch(m, cssid, ssid, schid);
+    if (!sch || !css_subch_visible(sch)) {
+        return -EINVAL;
+    }
 
-    s390_diag500_table[code] = fn;
+    vdev = virtio_ccw_get_vdev(sch);
+    if (vq_idx >= VIRTIO_QUEUE_MAX || !virtio_queue_get_num(vdev, vq_idx)) {
+        return -EINVAL;
+    }
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFICATION_DATA)) {
+        virtio_queue_set_shadow_avail_idx(virtio_get_queue(vdev, vq_idx),
+                                          (data >> 16) & 0xFFFF);
+    }
+
+    virtio_queue_notify(vdev, vq_idx);
+    return 0;
 }
 
 int s390_virtio_hypercall(CPUS390XState *env)
 {
-    s390_virtio_fn fn;
-
-    if (env->regs[1] < MAX_DIAG_SUBCODES) {
-        fn = s390_diag500_table[env->regs[1]];
-        if (fn) {
-            env->regs[2] = fn(&env->regs[2]);
-            return 0;
-        }
-    }
+    const uint64_t subcode = env->regs[1];
 
-    return -EINVAL;
+    switch (subcode) {
+    case KVM_S390_VIRTIO_NOTIFY:
+        env->regs[2] = handle_virtio_notify(env->regs[2]);
+        return 0;
+    case KVM_S390_VIRTIO_CCW_NOTIFY:
+        env->regs[2] = handle_virtio_ccw_notify(env->regs[2], env->regs[3]);
+        return 0;
+    default:
+        return -EINVAL;
+    }
 }
diff --git a/hw/s390x/s390-virtio-hcall.h b/hw/s390x/s390-virtio-hcall.h
index 3ae6d6ae3a..3d9fe147d2 100644
--- a/hw/s390x/s390-virtio-hcall.h
+++ b/hw/s390x/s390-virtio-hcall.h
@@ -18,8 +18,6 @@
 /* The only thing that we need from the old kvm_virtio.h file */
 #define KVM_S390_VIRTIO_NOTIFY 0
 
-typedef int (*s390_virtio_fn)(const uint64_t *args);
-void s390_register_virtio_hypercall(uint64_t code, s390_virtio_fn fn);
 int s390_virtio_hypercall(CPUS390XState *env);
 
 #endif /* HW_S390_VIRTIO_HCALL_H */
