From 5904ae4eba0928c35845720f9a630c19e48c2131 Mon Sep 17 00:00:00 2001
From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Wed, 1 Feb 2012 20:31:38 +0100
Subject: [PATCH] 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>
---
hw/hpet.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/hw/hpet.c b/hw/hpet.c
index ba36e103d0..76769d5493 100644
--- a/hw/hpet.c
+++ b/hw/hpet.c
@@ -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)