hpet: Save/restore cached RTC IRQ level

In legacy mode, the HPET suppresses the RTC interrupt delivery via IRQ
8 but keeps track of the RTC output level and applies it when legacy
mode is turned off again. This value has to be preserved across save/
restore as it cannot be reconstructed otherwise.

To document that a raised rtc_irq_level won't survive a vmload without
a hpet/rtc_irq_level subsection, add an explicit clearing to the reset
handler.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Jan Kiszka 2012-02-01 20:31:38 +01:00 committed by Anthony Liguori
parent 61b7b67df2
commit 5904ae4eba

View file

@ -240,6 +240,24 @@ static int hpet_post_load(void *opaque, int version_id)
return 0;
}
static bool hpet_rtc_irq_level_needed(void *opaque)
{
HPETState *s = opaque;
return s->rtc_irq_level != 0;
}
static const VMStateDescription vmstate_hpet_rtc_irq_level = {
.name = "hpet/rtc_irq_level",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT8(rtc_irq_level, HPETState),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_hpet_timer = {
.name = "hpet_timer",
.version_id = 1,
@ -273,6 +291,14 @@ static const VMStateDescription vmstate_hpet = {
VMSTATE_STRUCT_VARRAY_UINT8(timer, HPETState, num_timers, 0,
vmstate_hpet_timer, HPETTimer),
VMSTATE_END_OF_LIST()
},
.subsections = (VMStateSubsection[]) {
{
.vmsd = &vmstate_hpet_rtc_irq_level,
.needed = hpet_rtc_irq_level_needed,
}, {
/* empty */
}
}
};
@ -636,6 +662,9 @@ static void hpet_reset(DeviceState *d)
hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
hpet_cfg.hpet[s->hpet_id].address = sysbus_from_qdev(d)->mmio[0].addr;
count = 1;
/* to document that the RTC lowers its output on reset as well */
s->rtc_irq_level = 0;
}
static void hpet_handle_rtc_irq(void *opaque, int n, int level)