s390: sclp event support

Several SCLP features are considered to be events. Those events don't
provide SCLP commands on their own, instead they are all based on
Read Event Data, Write Event Data, Write Event Mask and the service
interrupt. Follow-on patches will provide SCLP's Signal Quiesce (via
system_powerdown) and the ASCII console.
Further down the road the sclp line mode console and configuration
change events (e.g. cpu hotplug) can be implemented.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 391 insertions, 0 deletions

diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
new file mode 100644
index 0000000000..1108e2d246
--- /dev/null
+++ b/hw/s390x/event-facility.c
@@ -0,0 +1,391 @@
+/*
+ * SCLP
+ *    Event Facility
+ *       handles SCLP event types
+ *          - Signal Quiesce - system power down
+ *          - ASCII Console Data - VT220 read and write
+ *
+ * Copyright IBM, Corp. 2012
+ *
+ * Authors:
+ *  Heinz Graalfs <graalfs@de.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at your
+ * option) any later version.  See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "monitor.h"
+#include "sysemu.h"
+
+#include "sclp.h"
+#include "event-facility.h"
+
+typedef struct EventTypesBus {
+    BusState qbus;
+} EventTypesBus;
+
+struct SCLPEventFacility {
+    EventTypesBus sbus;
+    DeviceState *qdev;
+    /* guest' receive mask */
+    unsigned int receive_mask;
+};
+
+/* return true if any child has event pending set */
+static bool event_pending(SCLPEventFacility *ef)
+{
+    BusChild *kid;
+    SCLPEvent *event;
+    SCLPEventClass *event_class;
+
+    QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
+        DeviceState *qdev = kid->child;
+        event = DO_UPCAST(SCLPEvent, qdev, qdev);
+        event_class = SCLP_EVENT_GET_CLASS(event);
+        if (event->event_pending &&
+            event_class->get_send_mask() & ef->receive_mask) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static unsigned int get_host_send_mask(SCLPEventFacility *ef)
+{
+    unsigned int mask;
+    BusChild *kid;
+    SCLPEventClass *child;
+
+    mask = 0;
+
+    QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
+        DeviceState *qdev = kid->child;
+        child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
+        mask |= child->get_send_mask();
+    }
+    return mask;
+}
+
+static unsigned int get_host_receive_mask(SCLPEventFacility *ef)
+{
+    unsigned int mask;
+    BusChild *kid;
+    SCLPEventClass *child;
+
+    mask = 0;
+
+    QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
+        DeviceState *qdev = kid->child;
+        child = SCLP_EVENT_GET_CLASS((SCLPEvent *) qdev);
+        mask |= child->get_receive_mask();
+    }
+    return mask;
+}
+
+static uint16_t write_event_length_check(SCCB *sccb)
+{
+    int slen;
+    unsigned elen = 0;
+    EventBufferHeader *event;
+    WriteEventData *wed = (WriteEventData *) sccb;
+
+    event = (EventBufferHeader *) &wed->ebh;
+    for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
+        elen = be16_to_cpu(event->length);
+        if (elen < sizeof(*event) || elen > slen) {
+            return SCLP_RC_EVENT_BUFFER_SYNTAX_ERROR;
+        }
+        event = (void *) event + elen;
+    }
+    if (slen) {
+        return SCLP_RC_INCONSISTENT_LENGTHS;
+    }
+    return SCLP_RC_NORMAL_COMPLETION;
+}
+
+static uint16_t handle_write_event_buf(SCLPEventFacility *ef,
+                                       EventBufferHeader *event_buf, SCCB *sccb)
+{
+    uint16_t rc;
+    BusChild *kid;
+    SCLPEvent *event;
+    SCLPEventClass *ec;
+
+    QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
+        DeviceState *qdev = kid->child;
+        event = (SCLPEvent *) qdev;
+        ec = SCLP_EVENT_GET_CLASS(event);
+
+        rc = SCLP_RC_INVALID_FUNCTION;
+        if (ec->write_event_data &&
+            ec->event_type() == event_buf->type) {
+            rc = ec->write_event_data(event, event_buf);
+            break;
+        }
+    }
+    return rc;
+}
+
+static uint16_t handle_sccb_write_events(SCLPEventFacility *ef, SCCB *sccb)
+{
+    uint16_t rc;
+    int slen;
+    unsigned elen = 0;
+    EventBufferHeader *event_buf;
+    WriteEventData *wed = (WriteEventData *) sccb;
+
+    event_buf = &wed->ebh;
+    rc = SCLP_RC_NORMAL_COMPLETION;
+
+    /* loop over all contained event buffers */
+    for (slen = sccb_data_len(sccb); slen > 0; slen -= elen) {
+        elen = be16_to_cpu(event_buf->length);
+
+        /* in case of a previous error mark all trailing buffers
+         * as not accepted */
+        if (rc != SCLP_RC_NORMAL_COMPLETION) {
+            event_buf->flags &= ~(SCLP_EVENT_BUFFER_ACCEPTED);
+        } else {
+            rc = handle_write_event_buf(ef, event_buf, sccb);
+        }
+        event_buf = (void *) event_buf + elen;
+    }
+    return rc;
+}
+
+static void write_event_data(SCLPEventFacility *ef, SCCB *sccb)
+{
+    if (sccb->h.function_code != SCLP_FC_NORMAL_WRITE) {
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
+        goto out;
+    }
+    if (be16_to_cpu(sccb->h.length) < 8) {
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
+        goto out;
+    }
+    /* first do a sanity check of the write events */
+    sccb->h.response_code = cpu_to_be16(write_event_length_check(sccb));
+
+    /* if no early error, then execute */
+    if (sccb->h.response_code == be16_to_cpu(SCLP_RC_NORMAL_COMPLETION)) {
+        sccb->h.response_code =
+                cpu_to_be16(handle_sccb_write_events(ef, sccb));
+    }
+
+out:
+    return;
+}
+
+static uint16_t handle_sccb_read_events(SCLPEventFacility *ef, SCCB *sccb,
+                                        unsigned int mask)
+{
+    uint16_t rc;
+    int slen;
+    unsigned elen = 0;
+    BusChild *kid;
+    SCLPEvent *event;
+    SCLPEventClass *ec;
+    EventBufferHeader *event_buf;
+    ReadEventData *red = (ReadEventData *) sccb;
+
+    event_buf = &red->ebh;
+    event_buf->length = 0;
+    slen = sizeof(sccb->data);
+
+    rc = SCLP_RC_NO_EVENT_BUFFERS_STORED;
+
+    QTAILQ_FOREACH(kid, &ef->sbus.qbus.children, sibling) {
+        DeviceState *qdev = kid->child;
+        event = (SCLPEvent *) qdev;
+        ec = SCLP_EVENT_GET_CLASS(event);
+
+        if (mask & ec->get_send_mask()) {
+            if (ec->read_event_data(event, event_buf, &slen)) {
+                rc = SCLP_RC_NORMAL_COMPLETION;
+            }
+        }
+        elen = be16_to_cpu(event_buf->length);
+        event_buf = (void *) event_buf + elen;
+    }
+
+    if (sccb->h.control_mask[2] & SCLP_VARIABLE_LENGTH_RESPONSE) {
+        /* architecture suggests to reset variable-length-response bit */
+        sccb->h.control_mask[2] &= ~SCLP_VARIABLE_LENGTH_RESPONSE;
+        /* with a new length value */
+        sccb->h.length = cpu_to_be16(SCCB_SIZE - slen);
+    }
+    return rc;
+}
+
+static void read_event_data(SCLPEventFacility *ef, SCCB *sccb)
+{
+    unsigned int sclp_active_selection_mask;
+    unsigned int sclp_cp_receive_mask;
+
+    ReadEventData *red = (ReadEventData *) sccb;
+
+    if (be16_to_cpu(sccb->h.length) != SCCB_SIZE) {
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
+        goto out;
+    }
+
+    sclp_cp_receive_mask = ef->receive_mask;
+
+    /* get active selection mask */
+    switch (sccb->h.function_code) {
+    case SCLP_UNCONDITIONAL_READ:
+        sclp_active_selection_mask = sclp_cp_receive_mask;
+        break;
+    case SCLP_SELECTIVE_READ:
+        if (!(sclp_cp_receive_mask & be32_to_cpu(red->mask))) {
+            sccb->h.response_code =
+                    cpu_to_be16(SCLP_RC_INVALID_SELECTION_MASK);
+            goto out;
+        }
+        sclp_active_selection_mask = be32_to_cpu(red->mask);
+        break;
+    default:
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_FUNCTION);
+        goto out;
+    }
+    sccb->h.response_code = cpu_to_be16(
+            handle_sccb_read_events(ef, sccb, sclp_active_selection_mask));
+
+out:
+    return;
+}
+
+static void write_event_mask(SCLPEventFacility *ef, SCCB *sccb)
+{
+    WriteEventMask *we_mask = (WriteEventMask *) sccb;
+
+    /* Attention: We assume that Linux uses 4-byte masks, what it actually
+       does. Architecture allows for masks of variable size, though */
+    if (be16_to_cpu(we_mask->mask_length) != 4) {
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_MASK_LENGTH);
+        goto out;
+    }
+
+    /* keep track of the guest's capability masks */
+    ef->receive_mask = be32_to_cpu(we_mask->cp_receive_mask);
+
+    /* return the SCLP's capability masks to the guest */
+    we_mask->send_mask = cpu_to_be32(get_host_send_mask(ef));
+    we_mask->receive_mask = cpu_to_be32(get_host_receive_mask(ef));
+
+    sccb->h.response_code = cpu_to_be16(SCLP_RC_NORMAL_COMPLETION);
+
+out:
+    return;
+}
+
+/* qemu object creation and initialization functions */
+
+#define TYPE_SCLP_EVENTS_BUS "s390-sclp-events-bus"
+
+static void sclp_events_bus_class_init(ObjectClass *klass, void *data)
+{
+}
+
+static const TypeInfo s390_sclp_events_bus_info = {
+    .name = TYPE_SCLP_EVENTS_BUS,
+    .parent = TYPE_BUS,
+    .class_init = sclp_events_bus_class_init,
+};
+
+static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
+{
+    switch (code) {
+    case SCLP_CMD_READ_EVENT_DATA:
+        read_event_data(ef, sccb);
+        break;
+    case SCLP_CMD_WRITE_EVENT_DATA:
+        write_event_data(ef, sccb);
+        break;
+    case SCLP_CMD_WRITE_EVENT_MASK:
+        write_event_mask(ef, sccb);
+        break;
+    default:
+        sccb->h.response_code = cpu_to_be16(SCLP_RC_INVALID_SCLP_COMMAND);
+        break;
+    }
+}
+
+static int init_event_facility(S390SCLPDevice *sdev)
+{
+    SCLPEventFacility *event_facility;
+
+    event_facility = g_malloc0(sizeof(SCLPEventFacility));
+    sdev->ef = event_facility;
+    sdev->sclp_command_handler = command_handler;
+    sdev->event_pending = event_pending;
+
+    /* Spawn a new sclp-events facility */
+    qbus_create_inplace(&event_facility->sbus.qbus,
+                        TYPE_SCLP_EVENTS_BUS, (DeviceState *)sdev, NULL);
+    event_facility->sbus.qbus.allow_hotplug = 0;
+    event_facility->qdev = (DeviceState *) sdev;
+
+    return 0;
+}
+
+static void init_event_facility_class(ObjectClass *klass, void *data)
+{
+    S390SCLPDeviceClass *k = SCLP_S390_DEVICE_CLASS(klass);
+
+    k->init = init_event_facility;
+}
+
+static TypeInfo s390_sclp_event_facility_info = {
+    .name          = "s390-sclp-event-facility",
+    .parent        = TYPE_DEVICE_S390_SCLP,
+    .instance_size = sizeof(S390SCLPDevice),
+    .class_init    = init_event_facility_class,
+};
+
+static int event_qdev_init(DeviceState *qdev)
+{
+    SCLPEvent *event = DO_UPCAST(SCLPEvent, qdev, qdev);
+    SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
+
+    return child->init(event);
+}
+
+static int event_qdev_exit(DeviceState *qdev)
+{
+    SCLPEvent *event = DO_UPCAST(SCLPEvent, qdev, qdev);
+    SCLPEventClass *child = SCLP_EVENT_GET_CLASS(event);
+    if (child->exit) {
+        child->exit(event);
+    }
+    return 0;
+}
+
+static void event_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->bus_type = TYPE_SCLP_EVENTS_BUS;
+    dc->unplug = qdev_simple_unplug_cb;
+    dc->init = event_qdev_init;
+    dc->exit = event_qdev_exit;
+}
+
+static TypeInfo s390_sclp_event_type_info = {
+    .name = TYPE_SCLP_EVENT,
+    .parent = TYPE_DEVICE,
+    .instance_size = sizeof(SCLPEvent),
+    .class_init = event_class_init,
+    .class_size = sizeof(SCLPEventClass),
+    .abstract = true,
+};
+
+static void register_types(void)
+{
+    type_register_static(&s390_sclp_events_bus_info);
+    type_register_static(&s390_sclp_event_facility_info);
+    type_register_static(&s390_sclp_event_type_info);
+}
+
+type_init(register_types)