qemu-e2k/hw/s390x/tod.c

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/*
* 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 "qemu/module.h"
#include "sysemu/kvm.h"
#include "sysemu/tcg.h"
#include "sysemu/qtest.h"
#include "migration/qemu-file-types.h"
#include "migration/register.h"
void s390_init_tod(void)
{
Object *obj;
if (kvm_enabled()) {
obj = object_new(TYPE_KVM_S390_TOD);
} else if (tcg_enabled()) {
obj = object_new(TYPE_QEMU_S390_TOD);
} else if (qtest_enabled()) {
return;
} else {
error_report("current accelerator not handled in s390_init_tod!");
abort();
}
qom: Drop parameter @errp of object_property_add() & friends The only way object_property_add() can fail is when a property with the same name already exists. Since our property names are all hardcoded, failure is a programming error, and the appropriate way to handle it is passing &error_abort. Same for its variants, except for object_property_add_child(), which additionally fails when the child already has a parent. Parentage is also under program control, so this is a programming error, too. We have a bit over 500 callers. Almost half of them pass &error_abort, slightly fewer ignore errors, one test case handles errors, and the remaining few callers pass them to their own callers. The previous few commits demonstrated once again that ignoring programming errors is a bad idea. Of the few ones that pass on errors, several violate the Error API. The Error ** argument must be NULL, &error_abort, &error_fatal, or a pointer to a variable containing NULL. Passing an argument of the latter kind twice without clearing it in between is wrong: if the first call sets an error, it no longer points to NULL for the second call. ich9_pm_add_properties(), sparc32_ledma_realize(), sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize() are wrong that way. When the one appropriate choice of argument is &error_abort, letting users pick the argument is a bad idea. Drop parameter @errp and assert the preconditions instead. There's one exception to "duplicate property name is a programming error": the way object_property_add() implements the magic (and undocumented) "automatic arrayification". Don't drop @errp there. Instead, rename object_property_add() to object_property_try_add(), and add the obvious wrapper object_property_add(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-15-armbru@redhat.com> [Two semantic rebase conflicts resolved]
2020-05-05 17:29:22 +02:00
object_property_add_child(qdev_get_machine(), TYPE_S390_TOD, obj);
object_unref(obj);
qdev_realize(DEVICE(obj), NULL, &error_fatal);
}
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("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 const 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);