[4/5] s390: sclp signal quiesce support

From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>

This implements the sclp signal quiesce event via the SCLP Event
Facility.
This allows to gracefully shutdown a guest by using system_powerdown
notifiers. 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 <graalfs@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com>
---
 hw/s390x/Makefile.objs    |   1 +
 hw/s390x/event-facility.c |   7 +++
 hw/s390x/sclpquiesce.c    | 123 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 131 insertions(+)
 create mode 100644 hw/s390x/sclpquiesce.c

On 02.10.2012, at 09:33, Jens Freimann wrote:

> From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
> 
> This implements the sclp signal quiesce event via the SCLP Event
> Facility.
> This allows to gracefully shutdown a guest by using system_powerdown
> notifiers. 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.

Doesn't ctrl-alt-del usually reboot the machine, not shut it down?


Alex

> 
> 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>
> ---
> hw/s390x/Makefile.objs    |   1 +
> hw/s390x/event-facility.c |   7 +++
> hw/s390x/sclpquiesce.c    | 123 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 131 insertions(+)
> create mode 100644 hw/s390x/sclpquiesce.c
> 
> diff --git a/hw/s390x/Makefile.objs b/hw/s390x/Makefile.objs
> index b32fc52..ed4e61a 100644
> --- a/hw/s390x/Makefile.objs
> +++ b/hw/s390x/Makefile.objs
> @@ -3,3 +3,4 @@ obj-y = s390-virtio-bus.o s390-virtio.o
> obj-y := $(addprefix ../,$(obj-y))
> obj-y += sclp.o
> obj-y += event-facility.o
> +obj-y += sclpquiesce.o
> diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
> index 1108e2d..9367660 100644
> --- a/hw/s390x/event-facility.c
> +++ b/hw/s390x/event-facility.c
> @@ -315,6 +315,7 @@ static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
> static int init_event_facility(S390SCLPDevice *sdev)
> {
>     SCLPEventFacility *event_facility;
> +    DeviceState *quiesce;
> 
>     event_facility = g_malloc0(sizeof(SCLPEventFacility));
>     sdev->ef = event_facility;
> @@ -327,6 +328,12 @@ static int init_event_facility(S390SCLPDevice *sdev)
>     event_facility->sbus.qbus.allow_hotplug = 0;
>     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/s390x/sclpquiesce.c b/hw/s390x/sclpquiesce.c
> new file mode 100644
> index 0000000..9a773b8
> --- /dev/null
> +++ b/hw/s390x/sclpquiesce.c
> @@ -0,0 +1,123 @@
> +/*
> + * SCLP event type
> + *    Signal Quiesce - trigger system powerdown request
> + *
> + * 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 <hw/qdev.h>
> +#include "sysemu.h"
> +#include "sclp.h"
> +#include "event-facility.h"
> +
> +typedef struct SignalQuiesce {
> +    EventBufferHeader ebh;
> +    uint16_t timeout;
> +    uint8_t unit;
> +} QEMU_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;
> +}
> +
> +typedef struct QuiesceNotifier QuiesceNotifier;
> +
> +static struct QuiesceNotifier {
> +    Notifier notifier;
> +    SCLPEvent *event;
> +} qn;
> +
> +static void quiesce_powerdown_req(Notifier *n, void *opaque)
> +{
> +    QuiesceNotifier *qn = container_of(n, QuiesceNotifier, notifier);
> +    SCLPEvent *event = qn->event;
> +
> +    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;
> +
> +    qn.notifier.notify = quiesce_powerdown_req;
> +    qn.event = event;
> +
> +    qemu_register_powerdown_notifier(&qn.notifier);
> +
> +    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)
> -- 
> 1.7.11.7
>

On 12/10/12 02:36, Alexander Graf wrote:
> 
> On 02.10.2012, at 09:33, Jens Freimann wrote:
> 
>> From: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
>>
>> This implements the sclp signal quiesce event via the SCLP Event
>> Facility.
>> This allows to gracefully shutdown a guest by using system_powerdown
>> notifiers. 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.
> 
> Doesn't ctrl-alt-del usually reboot the machine, not shut it down?

On my 390 systems it seems to shutdown, at least that happens on lpar and
z/VM as well as under KVM.