[Qemu-devel] [PATCH 4/6] s390: sclp signal quiesce support

[Christian Borntraeger]

From: Heinz Graalfs <address@hidden>

This implements the sclp signal quiesce event via the SCLP Event
Facility.
This allows to gracefully shutdown a guest by using system_powerdown.
It creates a service interrupt that will trigger a Read Event Data
command from the guest. This code will then add an event that is
interpreted by linux guests as ctrl-alt-del.

Signed-off-by: Heinz Graalfs <address@hidden>
Signed-off-by: Christian Borntraeger <address@hidden>
---
 hw/s390-event-facility.c |    6 +++
 hw/s390-sclpquiesce.c    |  113 ++++++++++++++++++++++++++++++++++++++++++++++
 hw/s390x/Makefile.objs   |    2 +-
 3 files changed, 120 insertions(+), 1 deletion(-)
 create mode 100644 hw/s390-sclpquiesce.c

diff --git a/hw/s390-event-facility.c b/hw/s390-event-facility.c
index 42ac102..e3c9c56 100644
--- a/hw/s390-event-facility.c
+++ b/hw/s390-event-facility.c
@@ -335,6 +335,7 @@ static int command_handler(SCCB *sccb, uint64_t code)
 static int init_event_facility(S390SCLPDevice *sdev)
 {
     SCLPEventFacility *event_facility;
+    DeviceState *quiesce;
 
     event_facility = g_malloc0(sizeof(SCLPEventFacility));
     sdev->instance = event_facility;
@@ -348,6 +349,11 @@ static int init_event_facility(S390SCLPDevice *sdev)
     event_facility->sbus.event_facility = event_facility;
     event_facility->qdev = (DeviceState *) sdev;
 
+    quiesce = qdev_create(&event_facility->sbus.qbus, "sclpquiesce");
+    if (!quiesce) {
+        return -1;
+    }
+    qdev_init_nofail(quiesce);
 
     return 0;
 }
diff --git a/hw/s390-sclpquiesce.c b/hw/s390-sclpquiesce.c
new file mode 100644
index 0000000..405664a
--- /dev/null
+++ b/hw/s390-sclpquiesce.c
@@ -0,0 +1,113 @@
+/*
+ * SCLP event type
+ *    Signal Quiesce - trigger system powerdown request
+ *
+ * Copyright IBM, Corp. 2007, 2012
+ *
+ * Authors:
+ *  Heinz Graalfs <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+#include "qdev.h"
+#include "sysemu.h"
+
+#include "s390-sclp.h"
+#include "s390-event-facility.h"
+
+typedef struct SignalQuiesce {
+    EventBufferHeader ebh;
+    uint16_t timeout;
+    uint8_t unit;
+} __attribute__((packed)) SignalQuiesce;
+
+static int event_type(void)
+{
+    return SCLP_EVENT_SIGNAL_QUIESCE;
+}
+
+static unsigned int send_mask(void)
+{
+    return SCLP_EVENT_MASK_SIGNAL_QUIESCE;
+}
+
+static unsigned int receive_mask(void)
+{
+    return 0;
+}
+
+static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
+                           int *slen)
+{
+    SignalQuiesce *sq = (SignalQuiesce *) evt_buf_hdr;
+
+    if (*slen < sizeof(SignalQuiesce)) {
+        return 0;
+    }
+
+    if (!event->event_pending) {
+        return 0;
+    }
+    event->event_pending = false;
+
+    sq->ebh.length = cpu_to_be16(sizeof(SignalQuiesce));
+    sq->ebh.type = SCLP_EVENT_SIGNAL_QUIESCE;
+    sq->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
+    /*
+     * system_powerdown does not have a timeout. Fortunately the
+     * timeout value is currently ignored by Linux, anyway
+     */
+    sq->timeout = cpu_to_be16(0);
+    sq->unit = cpu_to_be16(0);
+    *slen -= sizeof(SignalQuiesce);
+
+    return 1;
+}
+
+static void trigger_signal_quiesce(void *opaque, int n, int level)
+{
+    SCLPEvent *event = opaque;
+
+    event->event_pending = true;
+    /* trigger SCLP read operation */
+    sclp_service_interrupt(0);
+}
+
+static int quiesce_init(SCLPEvent *event)
+{
+    event->event_type = SCLP_EVENT_SIGNAL_QUIESCE;
+    qemu_system_powerdown = *qemu_allocate_irqs(trigger_signal_quiesce,
+                                                event, 1);
+    qemu_mutex_init(&event->lock);
+
+    return 0;
+}
+
+static void quiesce_class_init(ObjectClass *klass, void *data)
+{
+    SCLPEventClass *k = SCLP_EVENT_CLASS(klass);
+
+    k->init = quiesce_init;
+
+    k->get_send_mask = send_mask;
+    k->get_receive_mask = receive_mask;
+    k->event_type = event_type;
+    k->read_event_data = read_event_data;
+    k->write_event_data = NULL;
+}
+
+static TypeInfo sclp_quiesce_info = {
+    .name          = "sclpquiesce",
+    .parent        = TYPE_SCLP_EVENT,
+    .instance_size = sizeof(SCLPEvent),
+    .class_init    = quiesce_class_init,
+    .class_size    = sizeof(SCLPEventClass),
+};
+
+static void register_types(void)
+{
+    type_register_static(&sclp_quiesce_info);
+}
+type_init(register_types)
diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
index 5ebde3b..a3ab189 100644
--- a/hw/s390x/Makefile.objs
+++ b/hw/s390x/Makefile.objs
@@ -1,4 +1,4 @@
 obj-y = s390-virtio-bus.o s390-virtio.o
-obj-y += s390-sclp.o s390-event-facility.o
+obj-y += s390-sclp.o s390-event-facility.o s390-sclpquiesce.o
 
 obj-y := $(addprefix ../,$(obj-y))
-- 
1.7.10.5