[Qemu-devel] [PATCH 3/8] [PATCH RFC v3] s390-qemu: cpu hotplug - SCLP Event integration

["Jason J. Herne" <jjherne@us.ibm.com>]

From: "Jason J. Herne" <jjherne@us.ibm.com>

Add an sclp event for "cpu was hot plugged".  This allows Qemu to deliver an
SCLP interrupt to the guest stating that the requested cpu hotplug was
completed.

Signed-off-by: Jason J. Herne <jjherne@us.ibm.com>
---
 hw/s390x/Makefile.objs            |    2 +-
 hw/s390x/event-facility.c         |    7 +++
 hw/s390x/sclpcpu.c                |  120 +++++++++++++++++++++++++++++++++++++
 include/hw/s390x/event-facility.h |    3 +
 include/hw/s390x/sclp.h           |    1 +
 5 files changed, 132 insertions(+), 1 deletion(-)
 create mode 100644 hw/s390x/sclpcpu.c

diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
index 77e1218..104ae8e 100644
--- a/hw/s390x/Makefile.objs
+++ b/hw/s390x/Makefile.objs
@@ -2,7 +2,7 @@ obj-y = s390-virtio-bus.o s390-virtio.o
 obj-y += s390-virtio-hcall.o
 obj-y += sclp.o
 obj-y += event-facility.o
-obj-y += sclpquiesce.o
+obj-y += sclpquiesce.o sclpcpu.o
 obj-y += ipl.o
 obj-y += css.o
 obj-y += s390-virtio-ccw.o
diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
index 0faade0..aec35cb 100644
--- a/hw/s390x/event-facility.c
+++ b/hw/s390x/event-facility.c
@@ -317,6 +317,7 @@ static int init_event_facility(S390SCLPDevice *sdev)
 {
     SCLPEventFacility *event_facility;
     DeviceState *quiesce;
+    DeviceState *cpu_hotplug;
 
     event_facility = g_malloc0(sizeof(SCLPEventFacility));
     sdev->ef = event_facility;
@@ -335,6 +336,12 @@ static int init_event_facility(S390SCLPDevice *sdev)
     }
     qdev_init_nofail(quiesce);
 
+    cpu_hotplug = qdev_create(&event_facility->sbus.qbus, "sclpcpuhotplug");
+    if (!cpu_hotplug) {
+        return -1;
+    }
+    qdev_init_nofail(cpu_hotplug);
+
     return 0;
 }
 
diff --git a/hw/s390x/sclpcpu.c b/hw/s390x/sclpcpu.c
new file mode 100644
index 0000000..5b4139e
--- /dev/null
+++ b/hw/s390x/sclpcpu.c
@@ -0,0 +1,120 @@
+/*
+ * SCLP event type
+ *    Signal CPU - Trigger SCLP interrupt for system CPU configure or
+ *    de-configure
+ *
+ * Copyright IBM, Corp. 2013
+ *
+ * Authors:
+ *  Thang Pham <thang.pham@us.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 <hw/qdev.h>
+#include "sysemu/sysemu.h"
+#include "hw/s390x/sclp.h"
+#include "hw/s390x/event-facility.h"
+#include "cpu.h"
+#include "sysemu/cpus.h"
+#include "sysemu/kvm.h"
+
+typedef struct ConfigMgtData {
+    EventBufferHeader ebh;
+    uint8_t reserved;
+    uint8_t event_qualifier;
+} QEMU_PACKED ConfigMgtData;
+
+static qemu_irq irq_cpu_hotplug; /* Only used in this file */
+
+#define EVENT_QUAL_CPU_CHANGE  1
+
+void raise_irq_cpu_hotplug(void)
+{
+    qemu_irq_raise(irq_cpu_hotplug);
+}
+
+static int event_type(void)
+{
+    return SCLP_EVENT_CONFIG_MGT_DATA;
+}
+
+static unsigned int send_mask(void)
+{
+    return SCLP_EVENT_MASK_CONFIG_MGT_DATA;
+}
+
+static unsigned int receive_mask(void)
+{
+    return 0;
+}
+
+static int read_event_data(SCLPEvent *event, EventBufferHeader *evt_buf_hdr,
+                           int *slen)
+{
+    ConfigMgtData *cdata = (ConfigMgtData *) evt_buf_hdr;
+    if (*slen < sizeof(ConfigMgtData)) {
+        return 0;
+    }
+
+    /* Event is no longer pending */
+    if (!event->event_pending) {
+        return 0;
+    }
+    event->event_pending = false;
+
+    /* Event header data */
+    cdata->ebh.length = cpu_to_be16(sizeof(ConfigMgtData));
+    cdata->ebh.type = SCLP_EVENT_CONFIG_MGT_DATA;
+    cdata->ebh.flags |= SCLP_EVENT_BUFFER_ACCEPTED;
+
+    /* Trigger a rescan of CPUs by setting event qualifier */
+    cdata->event_qualifier = EVENT_QUAL_CPU_CHANGE;
+    *slen -= sizeof(ConfigMgtData);
+
+    return 1;
+}
+
+static void trigger_signal(void *opaque, int n, int level)
+{
+    SCLPEvent *event = opaque;
+    event->event_pending = true;
+
+    /* Trigger SCLP read operation */
+    sclp_service_interrupt(0);
+}
+
+static int irq_cpu_hotplug_init(SCLPEvent *event)
+{
+    irq_cpu_hotplug = *qemu_allocate_irqs(trigger_signal, event, 1);
+    return 0;
+}
+
+static void cpu_class_init(ObjectClass *klass, void *data)
+{
+    SCLPEventClass *k = SCLP_EVENT_CLASS(klass);
+
+    k->init = irq_cpu_hotplug_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_cpu_info = {
+    .name          = "sclpcpuhotplug",
+    .parent        = TYPE_SCLP_EVENT,
+    .instance_size = sizeof(SCLPEvent),
+    .class_init    = cpu_class_init,
+    .class_size    = sizeof(SCLPEventClass),
+};
+
+static void register_types(void)
+{
+    type_register_static(&sclp_cpu_info);
+}
+
+type_init(register_types)
+
diff --git a/include/hw/s390x/event-facility.h b/include/hw/s390x/event-facility.h
index 791ab2a..d63969f 100644
--- a/include/hw/s390x/event-facility.h
+++ b/include/hw/s390x/event-facility.h
@@ -17,14 +17,17 @@
 
 #include <hw/qdev.h>
 #include "qemu/thread.h"
+#include "hw/s390x/sclp.h"
 
 /* SCLP event types */
+#define SCLP_EVENT_CONFIG_MGT_DATA              0x04
 #define SCLP_EVENT_ASCII_CONSOLE_DATA           0x1a
 #define SCLP_EVENT_SIGNAL_QUIESCE               0x1d
 
 /* SCLP event masks */
 #define SCLP_EVENT_MASK_SIGNAL_QUIESCE          0x00000008
 #define SCLP_EVENT_MASK_MSG_ASCII               0x00000040
+#define SCLP_EVENT_MASK_CONFIG_MGT_DATA         0x10000000
 
 #define SCLP_UNCONDITIONAL_READ                 0x00
 #define SCLP_SELECTIVE_READ                     0x01
diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
index 89ae7d1..7728ad8 100644
--- a/include/hw/s390x/sclp.h
+++ b/include/hw/s390x/sclp.h
@@ -154,5 +154,6 @@ typedef struct S390SCLPDeviceClass {
 
 void s390_sclp_init(void);
 void sclp_service_interrupt(uint32_t sccb);
+void raise_irq_cpu_hotplug(void);
 
 #endif
-- 
1.7.10.4