diff --git a/hw/core/loader.c b/hw/core/loader.c
index 06bdbca537..bbb6e65bb5 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -191,7 +191,7 @@ void pstrcpy_targphys(const char *name, hwaddr dest, int buf_size,
         rom_add_blob_fixed(name, source, (nulp - source) + 1, dest);
     } else {
         rom_add_blob_fixed(name, source, buf_size, dest);
-        ptr = rom_ptr(dest + buf_size - 1);
+        ptr = rom_ptr(dest + buf_size - 1, sizeof(*ptr));
         *ptr = 0;
     }
 }
@@ -1165,7 +1165,7 @@ void rom_reset_order_override(void)
     fw_cfg_reset_order_override(fw_cfg);
 }
 
-static Rom *find_rom(hwaddr addr)
+static Rom *find_rom(hwaddr addr, size_t size)
 {
     Rom *rom;
 
@@ -1179,7 +1179,7 @@ static Rom *find_rom(hwaddr addr)
         if (rom->addr > addr) {
             continue;
         }
-        if (rom->addr + rom->romsize < addr) {
+        if (rom->addr + rom->romsize < addr + size) {
             continue;
         }
         return rom;
@@ -1249,11 +1249,11 @@ int rom_copy(uint8_t *dest, hwaddr addr, size_t size)
     return (d + l) - dest;
 }
 
-void *rom_ptr(hwaddr addr)
+void *rom_ptr(hwaddr addr, size_t size)
 {
     Rom *rom;
 
-    rom = find_rom(addr);
+    rom = find_rom(addr, size);
     if (!rom || !rom->data)
         return NULL;
     return rom->data + (addr - rom->addr);
diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c
index b9d92bf47e..1b4e32e58e 100644
--- a/hw/mips/mips_malta.c
+++ b/hw/mips/mips_malta.c
@@ -1133,11 +1133,13 @@ void mips_malta_init(MachineState *machine)
            a neat trick which allows bi-endian firmware. */
 #ifndef TARGET_WORDS_BIGENDIAN
         {
-            uint32_t *end, *addr = rom_ptr(FLASH_ADDRESS);
+            uint32_t *end, *addr;
+            const size_t swapsize = MIN(bios_size, 0x3e0000);
+            addr = rom_ptr(FLASH_ADDRESS, swapsize);
             if (!addr) {
                 addr = memory_region_get_ram_ptr(bios);
             }
-            end = (void *)addr + MIN(bios_size, 0x3e0000);
+            end = (void *)addr + swapsize;
             while (addr < end) {
                 bswap32s(addr);
                 addr++;
diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
index dc704b57d6..93282f7c59 100644
--- a/hw/s390x/Makefile.objs
+++ b/hw/s390x/Makefile.objs
@@ -14,6 +14,9 @@ obj-$(CONFIG_PCI) += s390-pci-bus.o s390-pci-inst.o
 obj-$(call lnot,$(CONFIG_PCI)) += s390-pci-stub.o
 obj-y += s390-skeys.o
 obj-y += s390-stattrib.o
+obj-y += tod.o
+obj-$(CONFIG_KVM) += tod-kvm.o
+obj-$(CONFIG_TCG) += tod-qemu.o
 obj-$(CONFIG_KVM) += s390-skeys-kvm.o
 obj-$(CONFIG_KVM) += s390-stattrib-kvm.o
 obj-y += s390-ccw.o
diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index 0d67349004..21f64ad26a 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -33,7 +33,6 @@
 #define KERN_PARM_AREA                  0x010480UL
 #define INITRD_START                    0x800000UL
 #define INITRD_PARM_START               0x010408UL
-#define INITRD_PARM_SIZE                0x010410UL
 #define PARMFILE_START                  0x001000UL
 #define ZIPL_IMAGE_START                0x009000UL
 #define IPL_PSW_MASK                    (PSW_MASK_32 | PSW_MASK_64)
@@ -165,12 +164,12 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
                 goto error;
             }
             /* if this is Linux use KERN_IMAGE_START */
-            magic = rom_ptr(LINUX_MAGIC_ADDR);
+            magic = rom_ptr(LINUX_MAGIC_ADDR, 6);
             if (magic && !memcmp(magic, "S390EP", 6)) {
                 pentry = KERN_IMAGE_START;
             } else {
                 /* if not Linux load the address of the (short) IPL PSW */
-                ipl_psw = rom_ptr(4);
+                ipl_psw = rom_ptr(4, 4);
                 if (ipl_psw) {
                     pentry = be32_to_cpu(*ipl_psw) & 0x7fffffffUL;
                 } else {
@@ -186,9 +185,12 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
          * loader) and it won't work. For this case we force it to 0x10000, too.
          */
         if (pentry == KERN_IMAGE_START || pentry == 0x800) {
+            char *parm_area = rom_ptr(KERN_PARM_AREA, strlen(ipl->cmdline) + 1);
             ipl->start_addr = KERN_IMAGE_START;
             /* Overwrite parameters in the kernel image, which are "rom" */
-            strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline);
+            if (parm_area) {
+                strcpy(parm_area, ipl->cmdline);
+            }
         } else {
             ipl->start_addr = pentry;
         }
@@ -196,6 +198,7 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
         if (ipl->initrd) {
             ram_addr_t initrd_offset;
             int initrd_size;
+            uint64_t *romptr;
 
             initrd_offset = INITRD_START;
             while (kernel_size + 0x100000 > initrd_offset) {
@@ -212,8 +215,11 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
              * we have to overwrite values in the kernel image,
              * which are "rom"
              */
-            stq_p(rom_ptr(INITRD_PARM_START), initrd_offset);
-            stq_p(rom_ptr(INITRD_PARM_SIZE), initrd_size);
+            romptr = rom_ptr(INITRD_PARM_START, 16);
+            if (romptr) {
+                stq_p(romptr, initrd_offset);
+                stq_p(romptr + 1, initrd_size);
+            }
         }
     }
     /*
@@ -535,7 +541,13 @@ void s390_ipl_reset_request(CPUState *cs, enum s390_reset reset_type)
             ipl->iplb_valid = s390_gen_initial_iplb(ipl);
         }
     }
-    qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
+    if (reset_type == S390_RESET_MODIFIED_CLEAR ||
+        reset_type == S390_RESET_LOAD_NORMAL) {
+        /* ignore -no-reboot, send no event  */
+        qemu_system_reset_request(SHUTDOWN_CAUSE_SUBSYSTEM_RESET);
+    } else {
+        qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
+    }
     /* as this is triggered by a CPU, make sure to exit the loop */
     if (tcg_enabled()) {
         cpu_loop_exit(cs);
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 7ae5fb38dd..7983185d04 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -35,6 +35,7 @@
 #include "migration/register.h"
 #include "cpu_models.h"
 #include "hw/nmi.h"
+#include "hw/s390x/tod.h"
 
 S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
 {
@@ -187,58 +188,6 @@ static void s390_memory_init(ram_addr_t mem_size)
     s390_stattrib_init();
 }
 
-#define S390_TOD_CLOCK_VALUE_MISSING    0x00
-#define S390_TOD_CLOCK_VALUE_PRESENT    0x01
-
-static void gtod_save(QEMUFile *f, void *opaque)
-{
-    uint64_t tod_low;
-    uint8_t tod_high;
-    int r;
-
-    r = s390_get_clock(&tod_high, &tod_low);
-    if (r) {
-        warn_report("Unable to get guest clock for migration: %s",
-                    strerror(-r));
-        error_printf("Guest clock will not be migrated "
-                     "which could cause the guest to hang.");
-        qemu_put_byte(f, S390_TOD_CLOCK_VALUE_MISSING);
-        return;
-    }
-
-    qemu_put_byte(f, S390_TOD_CLOCK_VALUE_PRESENT);
-    qemu_put_byte(f, tod_high);
-    qemu_put_be64(f, tod_low);
-}
-
-static int gtod_load(QEMUFile *f, void *opaque, int version_id)
-{
-    uint64_t tod_low;
-    uint8_t tod_high;
-    int r;
-
-    if (qemu_get_byte(f) == S390_TOD_CLOCK_VALUE_MISSING) {
-        warn_report("Guest clock was not migrated. This could "
-                    "cause the guest to hang.");
-        return 0;
-    }
-
-    tod_high = qemu_get_byte(f);
-    tod_low = qemu_get_be64(f);
-
-    r = s390_set_clock(&tod_high, &tod_low);
-    if (r) {
-        error_report("Unable to set KVM guest TOD clock: %s", strerror(-r));
-    }
-
-    return r;
-}
-
-static SaveVMHandlers savevm_gtod = {
-    .save_state = gtod_save,
-    .load_state = gtod_load,
-};
-
 static void s390_init_ipl_dev(const char *kernel_filename,
                               const char *kernel_cmdline,
                               const char *initrd_filename, const char *firmware,
@@ -363,8 +312,8 @@ static void ccw_init(MachineState *machine)
         s390_create_sclpconsole("sclplmconsole", serial_hd(1));
     }
 
-    /* Register savevm handler for guest TOD clock */
-    register_savevm_live(NULL, "todclock", 0, 1, &savevm_gtod, NULL);
+    /* init the TOD clock */
+    s390_init_tod();
 }
 
 static void s390_cpu_plug(HotplugHandler *hotplug_dev,
@@ -824,6 +773,8 @@ DEFINE_CCW_MACHINE(3_0, "3.0", true);
 static void ccw_machine_2_12_instance_options(MachineState *machine)
 {
     ccw_machine_3_0_instance_options(machine);
+    s390_cpudef_featoff_greater(11, 1, S390_FEAT_PPA15);
+    s390_cpudef_featoff_greater(11, 1, S390_FEAT_BPB);
 }
 
 static void ccw_machine_2_12_class_options(MachineClass *mc)
diff --git a/hw/s390x/tod-kvm.c b/hw/s390x/tod-kvm.c
new file mode 100644
index 0000000000..df564ab89c
--- /dev/null
+++ b/hw/s390x/tod-kvm.c
@@ -0,0 +1,64 @@
+/*
+ * TOD (Time Of Day) clock - KVM implementation
+ *
+ * Copyright 2018 Red Hat, Inc.
+ * Author(s): David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/s390x/tod.h"
+#include "kvm_s390x.h"
+
+static void kvm_s390_tod_get(const S390TODState *td, S390TOD *tod, Error **errp)
+{
+    int r;
+
+    r = kvm_s390_get_clock_ext(&tod->high, &tod->low);
+    if (r == -ENXIO) {
+        r = kvm_s390_get_clock(&tod->high, &tod->low);
+    }
+    if (r) {
+        error_setg(errp, "Unable to get KVM guest TOD clock: %s",
+                   strerror(-r));
+    }
+}
+
+static void kvm_s390_tod_set(S390TODState *td, const S390TOD *tod, Error **errp)
+{
+    int r;
+
+    r = kvm_s390_set_clock_ext(tod->high, tod->low);
+    if (r == -ENXIO) {
+        r = kvm_s390_set_clock(tod->high, tod->low);
+    }
+    if (r) {
+        error_setg(errp, "Unable to set KVM guest TOD clock: %s",
+                   strerror(-r));
+    }
+}
+
+static void kvm_s390_tod_class_init(ObjectClass *oc, void *data)
+{
+    S390TODClass *tdc = S390_TOD_CLASS(oc);
+
+    tdc->get = kvm_s390_tod_get;
+    tdc->set = kvm_s390_tod_set;
+}
+
+static TypeInfo kvm_s390_tod_info = {
+    .name = TYPE_KVM_S390_TOD,
+    .parent = TYPE_S390_TOD,
+    .instance_size = sizeof(S390TODState),
+    .class_init = kvm_s390_tod_class_init,
+    .class_size = sizeof(S390TODClass),
+};
+
+static void register_types(void)
+{
+    type_register_static(&kvm_s390_tod_info);
+}
+type_init(register_types);
diff --git a/hw/s390x/tod-qemu.c b/hw/s390x/tod-qemu.c
new file mode 100644
index 0000000000..59c015c69d
--- /dev/null
+++ b/hw/s390x/tod-qemu.c
@@ -0,0 +1,87 @@
+/*
+ * TOD (Time Of Day) clock - QEMU implementation
+ *
+ * Copyright 2018 Red Hat, Inc.
+ * Author(s): David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/s390x/tod.h"
+#include "qemu/timer.h"
+#include "qemu/cutils.h"
+#include "cpu.h"
+#include "tcg_s390x.h"
+
+static void qemu_s390_tod_get(const S390TODState *td, S390TOD *tod,
+                              Error **errp)
+{
+    *tod = td->base;
+
+    tod->low += time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+    if (tod->low < td->base.low) {
+        tod->high++;
+    }
+}
+
+static void qemu_s390_tod_set(S390TODState *td, const S390TOD *tod,
+                              Error **errp)
+{
+    CPUState *cpu;
+
+    td->base = *tod;
+
+    td->base.low -= time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+    if (td->base.low > tod->low) {
+        td->base.high--;
+    }
+
+    /*
+     * The TOD has been changed and we have to recalculate the CKC values
+     * for all CPUs. We do this asynchronously, as "SET CLOCK should be
+     * issued only while all other activity on all CPUs .. has been
+     * suspended".
+     */
+    CPU_FOREACH(cpu) {
+        async_run_on_cpu(cpu, tcg_s390_tod_updated, RUN_ON_CPU_NULL);
+    }
+}
+
+static void qemu_s390_tod_class_init(ObjectClass *oc, void *data)
+{
+    S390TODClass *tdc = S390_TOD_CLASS(oc);
+
+    tdc->get = qemu_s390_tod_get;
+    tdc->set = qemu_s390_tod_set;
+}
+
+static void qemu_s390_tod_init(Object *obj)
+{
+    S390TODState *td = S390_TOD(obj);
+    struct tm tm;
+
+    qemu_get_timedate(&tm, 0);
+    td->base.high = 0;
+    td->base.low = TOD_UNIX_EPOCH + (time2tod(mktimegm(&tm)) * 1000000000ULL);
+    if (td->base.low < TOD_UNIX_EPOCH) {
+        td->base.high += 1;
+    }
+}
+
+static TypeInfo qemu_s390_tod_info = {
+    .name = TYPE_QEMU_S390_TOD,
+    .parent = TYPE_S390_TOD,
+    .instance_size = sizeof(S390TODState),
+    .instance_init = qemu_s390_tod_init,
+    .class_init = qemu_s390_tod_class_init,
+    .class_size = sizeof(S390TODClass),
+};
+
+static void register_types(void)
+{
+    type_register_static(&qemu_s390_tod_info);
+}
+type_init(register_types);
diff --git a/hw/s390x/tod.c b/hw/s390x/tod.c
new file mode 100644
index 0000000000..1c63f411e6
--- /dev/null
+++ b/hw/s390x/tod.c
@@ -0,0 +1,130 @@
+/*
+ * TOD (Time Of Day) clock
+ *
+ * Copyright 2018 Red Hat, Inc.
+ * Author(s): David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/s390x/tod.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "sysemu/kvm.h"
+#include "migration/register.h"
+
+void s390_init_tod(void)
+{
+    Object *obj;
+
+    if (kvm_enabled()) {
+        obj = object_new(TYPE_KVM_S390_TOD);
+    } else {
+        obj = object_new(TYPE_QEMU_S390_TOD);
+    }
+    object_property_add_child(qdev_get_machine(), TYPE_S390_TOD, obj, NULL);
+    object_unref(obj);
+
+    qdev_init_nofail(DEVICE(obj));
+}
+
+S390TODState *s390_get_todstate(void)
+{
+    static S390TODState *ts;
+
+    if (!ts) {
+        ts = S390_TOD(object_resolve_path_type("", TYPE_S390_TOD, NULL));
+    }
+
+    return ts;
+}
+
+#define S390_TOD_CLOCK_VALUE_MISSING    0x00
+#define S390_TOD_CLOCK_VALUE_PRESENT    0x01
+
+static void s390_tod_save(QEMUFile *f, void *opaque)
+{
+    S390TODState *td = opaque;
+    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
+    Error *err = NULL;
+    S390TOD tod;
+
+    tdc->get(td, &tod, &err);
+    if (err) {
+        warn_report_err(err);
+        error_printf("Guest clock will not be migrated "
+                     "which could cause the guest to hang.");
+        qemu_put_byte(f, S390_TOD_CLOCK_VALUE_MISSING);
+        return;
+    }
+
+    qemu_put_byte(f, S390_TOD_CLOCK_VALUE_PRESENT);
+    qemu_put_byte(f, tod.high);
+    qemu_put_be64(f, tod.low);
+}
+
+static int s390_tod_load(QEMUFile *f, void *opaque, int version_id)
+{
+    S390TODState *td = opaque;
+    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
+    Error *err = NULL;
+    S390TOD tod;
+
+    if (qemu_get_byte(f) == S390_TOD_CLOCK_VALUE_MISSING) {
+        warn_report("Guest clock was not migrated. This could "
+                    "cause the guest to hang.");
+        return 0;
+    }
+
+    tod.high = qemu_get_byte(f);
+    tod.low = qemu_get_be64(f);
+
+    tdc->set(td, &tod, &err);
+    if (err) {
+        error_report_err(err);
+        return -1;
+    }
+    return 0;
+}
+
+static SaveVMHandlers savevm_tod = {
+    .save_state = s390_tod_save,
+    .load_state = s390_tod_load,
+};
+
+static void s390_tod_realize(DeviceState *dev, Error **errp)
+{
+    S390TODState *td = S390_TOD(dev);
+
+    /* Legacy migration interface */
+    register_savevm_live(NULL, "todclock", 0, 1, &savevm_tod, td);
+}
+
+static void s390_tod_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+
+    dc->desc = "TOD (Time Of Day) Clock";
+    dc->realize = s390_tod_realize;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+
+    /* We only have one TOD clock in the system attached to the machine */
+    dc->user_creatable = false;
+}
+
+static TypeInfo s390_tod_info = {
+    .name = TYPE_S390_TOD,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(S390TODState),
+    .class_init = s390_tod_class_init,
+    .class_size = sizeof(S390TODClass),
+    .abstract = true,
+};
+
+static void register_types(void)
+{
+    type_register_static(&s390_tod_info);
+}
+type_init(register_types);
diff --git a/hw/sparc/sun4m.c b/hw/sparc/sun4m.c
index b984d2da0e..21078cc121 100644
--- a/hw/sparc/sun4m.c
+++ b/hw/sparc/sun4m.c
@@ -272,8 +272,8 @@ static unsigned long sun4m_load_kernel(const char *kernel_filename,
         }
         if (initrd_size > 0) {
             for (i = 0; i < 64 * TARGET_PAGE_SIZE; i += TARGET_PAGE_SIZE) {
-                ptr = rom_ptr(KERNEL_LOAD_ADDR + i);
-                if (ldl_p(ptr) == 0x48647253) { // HdrS
+                ptr = rom_ptr(KERNEL_LOAD_ADDR + i, 24);
+                if (ptr && ldl_p(ptr) == 0x48647253) { /* HdrS */
                     stl_p(ptr + 16, INITRD_LOAD_ADDR);
                     stl_p(ptr + 20, initrd_size);
                     break;
diff --git a/hw/sparc64/sun4u.c b/hw/sparc64/sun4u.c
index 3975a7b65a..334dd7008e 100644
--- a/hw/sparc64/sun4u.c
+++ b/hw/sparc64/sun4u.c
@@ -186,8 +186,8 @@ static uint64_t sun4u_load_kernel(const char *kernel_filename,
         }
         if (*initrd_size > 0) {
             for (i = 0; i < 64 * TARGET_PAGE_SIZE; i += TARGET_PAGE_SIZE) {
-                ptr = rom_ptr(*kernel_addr + i);
-                if (ldl_p(ptr + 8) == 0x48647253) { /* HdrS */
+                ptr = rom_ptr(*kernel_addr + i, 32);
+                if (ptr && ldl_p(ptr + 8) == 0x48647253) { /* HdrS */
                     stl_p(ptr + 24, *initrd_addr + *kernel_addr);
                     stl_p(ptr + 28, *initrd_size);
                     break;
diff --git a/include/hw/loader.h b/include/hw/loader.h
index 5ed3fd8ae6..e98b84b8f9 100644
--- a/include/hw/loader.h
+++ b/include/hw/loader.h
@@ -226,7 +226,7 @@ void rom_set_fw(FWCfgState *f);
 void rom_set_order_override(int order);
 void rom_reset_order_override(void);
 int rom_copy(uint8_t *dest, hwaddr addr, size_t size);
-void *rom_ptr(hwaddr addr);
+void *rom_ptr(hwaddr addr, size_t size);
 void hmp_info_roms(Monitor *mon, const QDict *qdict);
 
 #define rom_add_file_fixed(_f, _a, _i)          \
diff --git a/include/hw/s390x/tod.h b/include/hw/s390x/tod.h
new file mode 100644
index 0000000000..413c0d7c02
--- /dev/null
+++ b/include/hw/s390x/tod.h
@@ -0,0 +1,65 @@
+/*
+ * TOD (Time Of Day) clock
+ *
+ * Copyright 2018 Red Hat, Inc.
+ * Author(s): David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_S390_TOD_H
+#define HW_S390_TOD_H
+
+#include "hw/qdev.h"
+
+typedef struct S390TOD {
+    uint8_t high;
+    uint64_t low;
+} S390TOD;
+
+#define TYPE_S390_TOD "s390-tod"
+#define S390_TOD(obj) OBJECT_CHECK(S390TODState, (obj), TYPE_S390_TOD)
+#define S390_TOD_CLASS(oc) OBJECT_CLASS_CHECK(S390TODClass, (oc), \
+                                              TYPE_S390_TOD)
+#define S390_TOD_GET_CLASS(obj) OBJECT_GET_CLASS(S390TODClass, (obj), \
+                                                 TYPE_S390_TOD)
+#define TYPE_KVM_S390_TOD TYPE_S390_TOD "-kvm"
+#define TYPE_QEMU_S390_TOD TYPE_S390_TOD "-qemu"
+
+typedef struct S390TODState {
+    /* private */
+    DeviceState parent_obj;
+
+    /* unused by KVM implementation */
+    S390TOD base;
+} S390TODState;
+
+typedef struct S390TODClass {
+    /* private */
+    DeviceClass parent_class;
+
+    /* public */
+    void (*get)(const S390TODState *td, S390TOD *tod, Error **errp);
+    void (*set)(S390TODState *td, const S390TOD *tod, Error **errp);
+} S390TODClass;
+
+/* The value of the TOD clock for 1.1.1970. */
+#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
+
+/* Converts ns to s390's clock format */
+static inline uint64_t time2tod(uint64_t ns)
+{
+    return (ns << 9) / 125 + (((ns & 0xff10000000000000ull) / 125) << 9);
+}
+
+/* Converts s390's clock format to ns */
+static inline uint64_t tod2time(uint64_t t)
+{
+    return ((t >> 9) * 125) + (((t & 0x1ff) * 125) >> 9);
+}
+
+void s390_init_tod(void);
+S390TODState *s390_get_todstate(void);
+
+#endif
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index b921c6f3b7..76ef6196a7 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -44,6 +44,10 @@ typedef enum ShutdownCause {
                                      turns that into a shutdown */
     SHUTDOWN_CAUSE_GUEST_PANIC,   /* Guest panicked, and command line turns
                                      that into a shutdown */
+    SHUTDOWN_CAUSE_SUBSYSTEM_RESET,/* Partial guest reset that does not trigger
+                                      QMP events and ignores --no-reboot. This
+                                      is useful for sanitize hypercalls on s390
+                                      that are used during kexec/kdump/boot */
     SHUTDOWN_CAUSE__MAX,
 } ShutdownCause;
 
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 82ff450f9a..64a8005a4b 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -239,7 +239,7 @@ static void arm_cpu_reset(CPUState *s)
 
         /* Load the initial SP and PC from offset 0 and 4 in the vector table */
         vecbase = env->v7m.vecbase[env->v7m.secure];
-        rom = rom_ptr(vecbase);
+        rom = rom_ptr(vecbase, 8);
         if (rom) {
             /* Address zero is covered by ROM which hasn't yet been
              * copied into physical memory.
diff --git a/target/s390x/Makefile.objs b/target/s390x/Makefile.objs
index 31932de9cf..22a9a9927a 100644
--- a/target/s390x/Makefile.objs
+++ b/target/s390x/Makefile.objs
@@ -5,6 +5,7 @@ obj-$(CONFIG_SOFTMMU) += machine.o ioinst.o arch_dump.o mmu_helper.o diag.o
 obj-$(CONFIG_SOFTMMU) += sigp.o
 obj-$(CONFIG_KVM) += kvm.o
 obj-$(call lnot,$(CONFIG_KVM)) += kvm-stub.o
+obj-$(call lnot,$(CONFIG_TCG)) += tcg-stub.o
 
 # build and run feature list generator
 feat-src = $(SRC_PATH)/target/$(TARGET_BASE_ARCH)/
diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
index c268065887..271c5ce652 100644
--- a/target/s390x/cpu.c
+++ b/target/s390x/cpu.c
@@ -30,7 +30,6 @@
 #include "kvm_s390x.h"
 #include "sysemu/kvm.h"
 #include "qemu-common.h"
-#include "qemu/cutils.h"
 #include "qemu/timer.h"
 #include "qemu/error-report.h"
 #include "trace.h"
@@ -219,11 +218,18 @@ static void s390_cpu_realizefn(DeviceState *dev, Error **errp)
 #endif
     s390_cpu_gdb_init(cs);
     qemu_init_vcpu(cs);
-#if !defined(CONFIG_USER_ONLY)
-    run_on_cpu(cs, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
-#else
-    cpu_reset(cs);
-#endif
+
+    /*
+     * KVM requires the initial CPU reset ioctl to be executed on the target
+     * CPU thread. CPU hotplug under single-threaded TCG will not work with
+     * run_on_cpu(), as run_on_cpu() will not work properly if called while
+     * the main thread is already running but the CPU hasn't been realized.
+     */
+    if (kvm_enabled()) {
+        run_on_cpu(cs, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
+    } else {
+        cpu_reset(cs);
+    }
 
     scc->parent_realize(dev, &err);
 out:
@@ -275,9 +281,6 @@ static void s390_cpu_initfn(Object *obj)
     CPUState *cs = CPU(obj);
     S390CPU *cpu = S390_CPU(obj);
     CPUS390XState *env = &cpu->env;
-#if !defined(CONFIG_USER_ONLY)
-    struct tm tm;
-#endif
 
     cs->env_ptr = env;
     cs->halted = 1;
@@ -286,10 +289,6 @@ static void s390_cpu_initfn(Object *obj)
                         s390_cpu_get_crash_info_qom, NULL, NULL, NULL, NULL);
     s390_cpu_model_register_props(obj);
 #if !defined(CONFIG_USER_ONLY)
-    qemu_get_timedate(&tm, 0);
-    env->tod_offset = TOD_UNIX_EPOCH +
-                      (time2tod(mktimegm(&tm)) * 1000000000ULL);
-    env->tod_basetime = 0;
     env->tod_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, s390x_tod_timer, cpu);
     env->cpu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, s390x_cpu_timer, cpu);
     s390_cpu_set_state(S390_CPU_STATE_STOPPED, cpu);
@@ -390,38 +389,6 @@ unsigned int s390_cpu_set_state(uint8_t cpu_state, S390CPU *cpu)
     return s390_count_running_cpus();
 }
 
-int s390_get_clock(uint8_t *tod_high, uint64_t *tod_low)
-{
-    int r = 0;
-
-    if (kvm_enabled()) {
-        r = kvm_s390_get_clock_ext(tod_high, tod_low);
-        if (r == -ENXIO) {
-            return kvm_s390_get_clock(tod_high, tod_low);
-        }
-    } else {
-        /* Fixme TCG */
-        *tod_high = 0;
-        *tod_low = 0;
-    }
-
-    return r;
-}
-
-int s390_set_clock(uint8_t *tod_high, uint64_t *tod_low)
-{
-    int r = 0;
-
-    if (kvm_enabled()) {
-        r = kvm_s390_set_clock_ext(tod_high, tod_low);
-        if (r == -ENXIO) {
-            return kvm_s390_set_clock(tod_high, tod_low);
-        }
-    }
-    /* Fixme TCG */
-    return r;
-}
-
 int s390_set_memory_limit(uint64_t new_limit, uint64_t *hw_limit)
 {
     if (kvm_enabled()) {
diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
index 6629a533f3..2c3dd2d189 100644
--- a/target/s390x/cpu.h
+++ b/target/s390x/cpu.h
@@ -130,8 +130,6 @@ struct CPUS390XState {
     uint64_t cpuid;
 #endif
 
-    uint64_t tod_offset;
-    uint64_t tod_basetime;
     QEMUTimer *tod_timer;
 
     QEMUTimer *cpu_timer;
@@ -714,8 +712,6 @@ static inline void s390_do_cpu_load_normal(CPUState *cs, run_on_cpu_data arg)
 
 
 /* cpu.c */
-int s390_get_clock(uint8_t *tod_high, uint64_t *tod_low);
-int s390_set_clock(uint8_t *tod_high, uint64_t *tod_low);
 void s390_crypto_reset(void);
 bool s390_get_squash_mcss(void);
 int s390_set_memory_limit(uint64_t new_limit, uint64_t *hw_limit);
diff --git a/target/s390x/gen-features.c b/target/s390x/gen-features.c
index 0cdbc15378..6626b6f565 100644
--- a/target/s390x/gen-features.c
+++ b/target/s390x/gen-features.c
@@ -512,6 +512,8 @@ static uint16_t default_GEN11_GA1[] = {
     S390_FEAT_IPTE_RANGE,
     S390_FEAT_ACCESS_EXCEPTION_FS_INDICATION,
     S390_FEAT_GROUP_MSA_EXT_4,
+    S390_FEAT_PPA15,
+    S390_FEAT_BPB,
 };
 
 #define default_GEN11_GA2 EmptyFeat
diff --git a/target/s390x/helper.h b/target/s390x/helper.h
index 59cba86a27..97c60ca7bc 100644
--- a/target/s390x/helper.h
+++ b/target/s390x/helper.h
@@ -127,6 +127,7 @@ DEF_HELPER_4(diag, void, env, i32, i32, i32)
 DEF_HELPER_3(load_psw, noreturn, env, i64, i64)
 DEF_HELPER_FLAGS_2(spx, TCG_CALL_NO_RWG, void, env, i64)
 DEF_HELPER_FLAGS_1(stck, TCG_CALL_NO_RWG_SE, i64, env)
+DEF_HELPER_FLAGS_2(sck, TCG_CALL_NO_RWG, i32, env, i64)
 DEF_HELPER_FLAGS_2(sckc, TCG_CALL_NO_RWG, void, env, i64)
 DEF_HELPER_FLAGS_2(sckpf, TCG_CALL_NO_RWG, void, env, i64)
 DEF_HELPER_FLAGS_1(stckc, TCG_CALL_NO_RWG, i64, env)
diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def
index 157619403d..5c6f33ed9c 100644
--- a/target/s390x/insn-data.def
+++ b/target/s390x/insn-data.def
@@ -997,8 +997,7 @@
 /* SET ADDRESS SPACE CONTROL FAST */
     C(0xb279, SACF,    S,     Z,   0, a2, 0, 0, sacf, 0)
 /* SET CLOCK */
-    /* ??? Not implemented - is it necessary? */
-    C(0xb204, SCK,     S,     Z,   0, 0, 0, 0, 0, 0)
+    C(0xb204, SCK,     S,     Z,   la2, 0, 0, 0, sck, 0)
 /* SET CLOCK COMPARATOR */
     C(0xb206, SCKC,    S,     Z,   0, m2_64a, 0, 0, sckc, 0)
 /* SET CLOCK PROGRAMMABLE FIELD */
diff --git a/target/s390x/internal.h b/target/s390x/internal.h
index e392a02d12..f2a771e2b4 100644
--- a/target/s390x/internal.h
+++ b/target/s390x/internal.h
@@ -237,21 +237,6 @@ enum cc_op {
     CC_OP_MAX
 };
 
-/* The value of the TOD clock for 1.1.1970. */
-#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
-
-/* Converts ns to s390's clock format */
-static inline uint64_t time2tod(uint64_t ns)
-{
-    return (ns << 9) / 125;
-}
-
-/* Converts s390's clock format to ns */
-static inline uint64_t tod2time(uint64_t t)
-{
-    return (t * 125) >> 9;
-}
-
 static inline hwaddr decode_basedisp_s(CPUS390XState *env, uint32_t ipb,
                                        uint8_t *ar)
 {
diff --git a/target/s390x/kvm-stub.c b/target/s390x/kvm-stub.c
index 29b10542cc..bf7795e47a 100644
--- a/target/s390x/kvm-stub.c
+++ b/target/s390x/kvm-stub.c
@@ -60,12 +60,12 @@ int kvm_s390_get_clock_ext(uint8_t *tod_high, uint64_t *tod_low)
     return -ENOSYS;
 }
 
-int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low)
+int kvm_s390_set_clock(uint8_t tod_high, uint64_t tod_low)
 {
     return -ENOSYS;
 }
 
-int kvm_s390_set_clock_ext(uint8_t *tod_high, uint64_t *tod_low)
+int kvm_s390_set_clock_ext(uint8_t tod_high, uint64_t tod_low)
 {
     return -ENOSYS;
 }
diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
index ac370da281..d923cf4240 100644
--- a/target/s390x/kvm.c
+++ b/target/s390x/kvm.c
@@ -666,13 +666,13 @@ int kvm_s390_get_clock_ext(uint8_t *tod_high, uint64_t *tod_low)
     return r;
 }
 
-int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low)
+int kvm_s390_set_clock(uint8_t tod_high, uint64_t tod_low)
 {
     int r;
     struct kvm_device_attr attr = {
         .group = KVM_S390_VM_TOD,
         .attr = KVM_S390_VM_TOD_LOW,
-        .addr = (uint64_t)tod_low,
+        .addr = (uint64_t)&tod_low,
     };
 
     r = kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr);
@@ -681,15 +681,15 @@ int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_low)
     }
 
     attr.attr = KVM_S390_VM_TOD_HIGH;
-    attr.addr = (uint64_t)tod_high;
+    attr.addr = (uint64_t)&tod_high;
     return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr);
 }
 
-int kvm_s390_set_clock_ext(uint8_t *tod_high, uint64_t *tod_low)
+int kvm_s390_set_clock_ext(uint8_t tod_high, uint64_t tod_low)
 {
     struct kvm_s390_vm_tod_clock gtod = {
-        .epoch_idx = *tod_high,
-        .tod  = *tod_low,
+        .epoch_idx = tod_high,
+        .tod  = tod_low,
     };
     struct kvm_device_attr attr = {
         .group = KVM_S390_VM_TOD,
@@ -752,12 +752,23 @@ int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, uint8_t ar, void *hostbuf,
  */
 static void *legacy_s390_alloc(size_t size, uint64_t *align, bool shared)
 {
-    void *mem;
+    static void *mem;
+
+    if (mem) {
+        /* we only support one allocation, which is enough for initial ram */
+        return NULL;
+    }
 
     mem = mmap((void *) 0x800000000ULL, size,
                PROT_EXEC|PROT_READ|PROT_WRITE,
                MAP_SHARED | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
-    return mem == MAP_FAILED ? NULL : mem;
+    if (mem == MAP_FAILED) {
+        mem = NULL;
+    }
+    if (mem && align) {
+        *align = QEMU_VMALLOC_ALIGN;
+    }
+    return mem;
 }
 
 static uint8_t const *sw_bp_inst;
diff --git a/target/s390x/kvm_s390x.h b/target/s390x/kvm_s390x.h
index c383bf4ee9..6e52287da3 100644
--- a/target/s390x/kvm_s390x.h
+++ b/target/s390x/kvm_s390x.h
@@ -10,6 +10,8 @@
 #ifndef KVM_S390X_H
 #define KVM_S390X_H
 
+#include "cpu-qom.h"
+
 struct kvm_s390_irq;
 
 void kvm_s390_floating_interrupt_legacy(struct kvm_s390_irq *irq);
@@ -25,8 +27,8 @@ int kvm_s390_get_ri(void);
 int kvm_s390_get_gs(void);
 int kvm_s390_get_clock(uint8_t *tod_high, uint64_t *tod_clock);
 int kvm_s390_get_clock_ext(uint8_t *tod_high, uint64_t *tod_clock);
-int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_clock);
-int kvm_s390_set_clock_ext(uint8_t *tod_high, uint64_t *tod_clock);
+int kvm_s390_set_clock(uint8_t tod_high, uint64_t tod_clock);
+int kvm_s390_set_clock_ext(uint8_t tod_high, uint64_t tod_clock);
 void kvm_s390_enable_css_support(S390CPU *cpu);
 int kvm_s390_assign_subch_ioeventfd(EventNotifier *notifier, uint32_t sch,
                                     int vq, bool assign);
diff --git a/target/s390x/machine.c b/target/s390x/machine.c
index 84b4928755..bd3230d027 100644
--- a/target/s390x/machine.c
+++ b/target/s390x/machine.c
@@ -19,6 +19,7 @@
 #include "cpu.h"
 #include "internal.h"
 #include "kvm_s390x.h"
+#include "tcg_s390x.h"
 #include "sysemu/kvm.h"
 
 static int cpu_post_load(void *opaque, int version_id)
@@ -34,6 +35,11 @@ static int cpu_post_load(void *opaque, int version_id)
         return kvm_s390_vcpu_interrupt_post_load(cpu);
     }
 
+    if (tcg_enabled()) {
+        /* Rearm the CKC timer if necessary */
+        tcg_s390_tod_updated(CPU(cpu), RUN_ON_CPU_NULL);
+    }
+
     return 0;
 }
 
diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c
index de1ced2082..3f91579570 100644
--- a/target/s390x/misc_helper.c
+++ b/target/s390x/misc_helper.c
@@ -28,6 +28,8 @@
 #include "qemu/timer.h"
 #include "exec/exec-all.h"
 #include "exec/cpu_ldst.h"
+#include "qapi/error.h"
+#include "tcg_s390x.h"
 
 #if !defined(CONFIG_USER_ONLY)
 #include "sysemu/cpus.h"
@@ -39,6 +41,7 @@
 #include "hw/s390x/ioinst.h"
 #include "hw/s390x/s390-pci-inst.h"
 #include "hw/boards.h"
+#include "hw/s390x/tod.h"
 #endif
 
 /* #define DEBUG_HELPER */
@@ -138,30 +141,69 @@ void HELPER(spx)(CPUS390XState *env, uint64_t a1)
 /* Store Clock */
 uint64_t HELPER(stck)(CPUS390XState *env)
 {
-    uint64_t time;
+    S390TODState *td = s390_get_todstate();
+    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
+    S390TOD tod;
 
-    time = env->tod_offset +
-        time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - env->tod_basetime);
-
-    return time;
+    tdc->get(td, &tod, &error_abort);
+    return tod.low;
 }
 
-/* Set Clock Comparator */
-void HELPER(sckc)(CPUS390XState *env, uint64_t time)
+static void update_ckc_timer(CPUS390XState *env)
 {
-    if (time == -1ULL) {
+    S390TODState *td = s390_get_todstate();
+    uint64_t time;
+
+    /* stop the timer and remove pending CKC IRQs */
+    timer_del(env->tod_timer);
+    g_assert(qemu_mutex_iothread_locked());
+    env->pending_int &= ~INTERRUPT_EXT_CLOCK_COMPARATOR;
+
+    /* the tod has to exceed the ckc, this can never happen if ckc is all 1's */
+    if (env->ckc == -1ULL) {
         return;
     }
 
-    env->ckc = time;
-
     /* difference between origins */
-    time -= env->tod_offset;
+    time = env->ckc - td->base.low;
 
     /* nanoseconds */
     time = tod2time(time);
 
-    timer_mod(env->tod_timer, env->tod_basetime + time);
+    timer_mod(env->tod_timer, time);
+}
+
+/* Set Clock Comparator */
+void HELPER(sckc)(CPUS390XState *env, uint64_t ckc)
+{
+    env->ckc = ckc;
+
+    qemu_mutex_lock_iothread();
+    update_ckc_timer(env);
+    qemu_mutex_unlock_iothread();
+}
+
+void tcg_s390_tod_updated(CPUState *cs, run_on_cpu_data opaque)
+{
+    S390CPU *cpu = S390_CPU(cs);
+
+    update_ckc_timer(&cpu->env);
+}
+
+/* Set Clock */
+uint32_t HELPER(sck)(CPUS390XState *env, uint64_t tod_low)
+{
+    S390TODState *td = s390_get_todstate();
+    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
+    S390TOD tod = {
+        .high = 0,
+        .low = tod_low,
+    };
+
+    qemu_mutex_lock_iothread();
+    tdc->set(td, &tod, &error_abort);
+    qemu_mutex_unlock_iothread();
+    return 0;
 }
 
 /* Set Tod Programmable Field */
diff --git a/target/s390x/tcg-stub.c b/target/s390x/tcg-stub.c
new file mode 100644
index 0000000000..c93501db0b
--- /dev/null
+++ b/target/s390x/tcg-stub.c
@@ -0,0 +1,20 @@
+/*
+ * QEMU TCG support -- s390x specific function stubs.
+ *
+ * Copyright (C) 2018 Red Hat Inc
+ *
+ * Authors:
+ *   David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "cpu.h"
+#include "tcg_s390x.h"
+
+void tcg_s390_tod_updated(CPUState *cs, run_on_cpu_data opaque)
+{
+}
diff --git a/target/s390x/tcg_s390x.h b/target/s390x/tcg_s390x.h
new file mode 100644
index 0000000000..4e308aa0ce
--- /dev/null
+++ b/target/s390x/tcg_s390x.h
@@ -0,0 +1,18 @@
+/*
+ * QEMU TCG support -- s390x specific functions.
+ *
+ * Copyright 2018 Red Hat, Inc.
+ *
+ * Authors:
+ *   David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef TCG_S390X_H
+#define TCG_S390X_H
+
+void tcg_s390_tod_updated(CPUState *cs, run_on_cpu_data opaque);
+
+#endif /* TCG_S390X_H */
diff --git a/target/s390x/translate.c b/target/s390x/translate.c
index fdfec7feba..57c03cbf58 100644
--- a/target/s390x/translate.c
+++ b/target/s390x/translate.c
@@ -4016,6 +4016,15 @@ static DisasJumpType op_stcke(DisasContext *s, DisasOps *o)
     return DISAS_NEXT;
 }
 
+static DisasJumpType op_sck(DisasContext *s, DisasOps *o)
+{
+    check_privileged(s);
+    tcg_gen_qemu_ld_i64(o->in1, o->addr1, get_mem_index(s), MO_TEQ | MO_ALIGN);
+    gen_helper_sck(cc_op, cpu_env, o->in1);
+    set_cc_static(s);
+    return DISAS_NEXT;
+}
+
 static DisasJumpType op_sckc(DisasContext *s, DisasOps *o)
 {
     check_privileged(s);
diff --git a/vl.c b/vl.c
index ef6cfcec40..9442beee21 100644
--- a/vl.c
+++ b/vl.c
@@ -1645,7 +1645,7 @@ void qemu_system_reset(ShutdownCause reason)
     } else {
         qemu_devices_reset();
     }
-    if (reason) {
+    if (reason != SHUTDOWN_CAUSE_SUBSYSTEM_RESET) {
         qapi_event_send_reset(shutdown_caused_by_guest(reason),
                               &error_abort);
     }
@@ -1691,7 +1691,7 @@ void qemu_system_guest_panicked(GuestPanicInformation *info)
 
 void qemu_system_reset_request(ShutdownCause reason)
 {
-    if (no_reboot) {
+    if (no_reboot && reason != SHUTDOWN_CAUSE_SUBSYSTEM_RESET) {
         shutdown_requested = reason;
     } else {
         reset_requested = reason;