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s390x/tcg: properly implement the TOD

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Right now, each CPU has its own TOD. Especially, the TOD will differ
based on creation time of a CPU - e.g. when hotplugging a CPU the times
will differ quite a lot, resulting in stall warnings in the guest.

Let's use a single TOD by implementing our new TOD device. Prepare it
for TOD-clock epoch extension.

Most importantly, whenever we set the TOD, we have to update the CKC
timer.

Introduce "tcg_s390x.h" just like "kvm_s390x.h" for tcg specific
function declarations that should not go into cpu.h.

Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180627134410.4901-6-david@redhat.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
This commit is contained in:
David Hildenbrand 2018-06-27 15:44:06 +02:00 • committed by Cornelia Huck
parent f777b20544
commit 7de3b1cdc6
8 changed files with 109 additions and 34 deletions
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46
hw/s390x/tod-qemu.c
View file

@ -11,19 +11,43 @@
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/s390x/tod.h"
#include "qemu/timer.h"
#include "qemu/cutils.h"
#include "cpu.h"
#include "tcg_s390x.h"
static void qemu_s390_tod_get(const S390TODState *td, S390TOD *tod,
Error **errp)
{
/* FIXME */
tod->high = 0;
tod->low = 0;
*tod = td->base;
tod->low += time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
if (tod->low < td->base.low) {
tod->high++;
}
}
static void qemu_s390_tod_set(S390TODState *td, const S390TOD *tod,
Error **errp)
{
/* FIXME */
CPUState *cpu;
td->base = *tod;
td->base.low -= time2tod(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
if (td->base.low > tod->low) {
td->base.high--;
}
/*
* The TOD has been changed and we have to recalculate the CKC values
* for all CPUs. We do this asynchronously, as "SET CLOCK should be
* issued only while all other activity on all CPUs .. has been
* suspended".
*/
CPU_FOREACH(cpu) {
async_run_on_cpu(cpu, tcg_s390_tod_updated, RUN_ON_CPU_NULL);
}
}
static void qemu_s390_tod_class_init(ObjectClass *oc, void *data)
@ -34,10 +58,24 @@ static void qemu_s390_tod_class_init(ObjectClass *oc, void *data)
tdc->set = qemu_s390_tod_set;
}
static void qemu_s390_tod_init(Object *obj)
{
S390TODState *td = S390_TOD(obj);
struct tm tm;
qemu_get_timedate(&tm, 0);
td->base.high = 0;
td->base.low = TOD_UNIX_EPOCH + (time2tod(mktimegm(&tm)) * 1000000000ULL);
if (td->base.low < TOD_UNIX_EPOCH) {
td->base.high += 1;
}
}
static TypeInfo qemu_s390_tod_info = {
.name = TYPE_QEMU_S390_TOD,
.parent = TYPE_S390_TOD,
.instance_size = sizeof(S390TODState),
.instance_init = qemu_s390_tod_init,
.class_init = qemu_s390_tod_class_init,
.class_size = sizeof(S390TODClass),
};

11
hw/s390x/tod.c
View file

@ -30,6 +30,17 @@ void s390_init_tod(void)
qdev_init_nofail(DEVICE(obj));
}
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