To enable migration between accelerated and non-accelerated APIC models,
we will need to handle the timer saving and restoring specially and can
no longer rely on the automatics of VMSTATE_TIMER. Specifically,
accelerated model will not start any QEMUTimer.
This patch therefore factors out the generic bits into apic_next_timer
and uses the post-load callback to implemented model-specific logic.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
hw/apic.c | 33 +++++++++++++++------------------
hw/apic_common.c | 41 +++++++++++++++++++++++++++++++++++++++--
hw/apic_internal.h | 2 ++
3 files changed, 56 insertions(+), 20 deletions(-)
diff --git a/hw/apic.c b/hw/apic.c
index 8f1d5aa..94b0841 100644
--- a/hw/apic.c
+++ b/hw/apic.c
@@ -527,25 +527,9 @@ static uint32_t apic_get_current_count(APICCommonState *s)
static void apic_timer_update(APICCommonState *s, int64_t current_time)
{
- int64_t next_time, d;
-
- if (!(s->lvt[APIC_LVT_TIMER] & APIC_LVT_MASKED)) {
- d = (current_time - s->initial_count_load_time) >>
- s->count_shift;
- if (s->lvt[APIC_LVT_TIMER] & APIC_LVT_TIMER_PERIODIC) {
- if (!s->initial_count)
- goto no_timer;
- d = ((d / ((uint64_t)s->initial_count + 1)) + 1) * ((uint64_t)s->initial_count + 1);
- } else {
- if (d >= s->initial_count)
- goto no_timer;
- d = (uint64_t)s->initial_count + 1;
- }
- next_time = s->initial_count_load_time + (d << s->count_shift);
- qemu_mod_timer(s->timer, next_time);
- s->next_time = next_time;
+ if (apic_next_timer(s, current_time)) {
+ qemu_mod_timer(s->timer, s->next_time);
} else {
- no_timer:
qemu_del_timer(s->timer);
}
}
@@ -759,6 +743,18 @@ static void apic_mem_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
}
}
+static int apic_post_load(void *opaque, int version_id)
+{
+ APICState *s = opaque;
+
+ if (s->apic.timer_expiry != -1) {
+ qemu_mod_timer(s->apic.timer, s->apic.timer_expiry);
+ } else {
+ qemu_del_timer(s->apic.timer);
+ }
+ return 0;
+}
+
static const MemoryRegionOps apic_io_ops = {
.old_mmio = {
.read = { apic_mem_readb, apic_mem_readw, apic_mem_readl, },
@@ -781,6 +777,7 @@ static const VMStateDescription vmstate_apic = {
.version_id = APIC_VMSTATE_VERSION,
.minimum_version_id = 3,
.minimum_version_id_old = 1,
+ .post_load = apic_post_load,
.fields = (VMStateField[]) {
VMSTATE_STRUCT(apic, APICState, 0, vmstate_apic_common,
APICCommonState),
diff --git a/hw/apic_common.c b/hw/apic_common.c
index 455d44c..1aeb909 100644
--- a/hw/apic_common.c
+++ b/hw/apic_common.c
@@ -95,6 +95,39 @@ void apic_deliver_nmi(DeviceState *d)
info->external_nmi(s);
}
+bool apic_next_timer(APICCommonState *s, int64_t current_time)
+{
+ int64_t d;
+
+ /* We need to store the timer state separately to support APIC
+ * implementations that maintain a non-QEMU timer, e.g. inside the
+ * host kernel. This open-coded state allows us to migrate between
+ * both models. */
+ s->timer_expiry = -1;
+
+ if (s->lvt[APIC_LVT_TIMER] & APIC_LVT_MASKED) {
+ return false;
+ }
+
+ d = (current_time - s->initial_count_load_time) >> s->count_shift;
+
+ if (s->lvt[APIC_LVT_TIMER] & APIC_LVT_TIMER_PERIODIC) {
+ if (!s->initial_count) {
+ return false;
+ }
+ d = ((d / ((uint64_t)s->initial_count + 1)) + 1) *
+ ((uint64_t)s->initial_count + 1);
+ } else {
+ if (d >= s->initial_count) {
+ return false;
+ }
+ d = (uint64_t)s->initial_count + 1;
+ }
+ s->next_time = s->initial_count_load_time + (d << s->count_shift);
+ s->timer_expiry = s->next_time;
+ return true;
+}
+
void apic_init_reset(DeviceState *d)
{
APICCommonState *s = DO_UPCAST(APICCommonState, busdev.qdev, d);
@@ -122,7 +155,10 @@ void apic_init_reset(DeviceState *d)
s->next_time = 0;
s->wait_for_sipi = 1;
- qemu_del_timer(s->timer);
+ if (s->timer) {
+ qemu_del_timer(s->timer);
+ }
+ s->timer_expiry = -1;
}
void apic_reset_common(DeviceState *d)
@@ -212,7 +248,8 @@ const VMStateDescription vmstate_apic_common = {
VMSTATE_UINT32(initial_count, APICCommonState),
VMSTATE_INT64(initial_count_load_time, APICCommonState),
VMSTATE_INT64(next_time, APICCommonState),
- VMSTATE_TIMER(timer, APICCommonState),
+ VMSTATE_INT64(timer_expiry,
+ APICCommonState), /* open-coded timer state */
VMSTATE_END_OF_LIST()
}
};
diff --git a/hw/apic_internal.h b/hw/apic_internal.h
index 2ca18d4..eaddf7f 100644
--- a/hw/apic_internal.h
+++ b/hw/apic_internal.h
@@ -92,6 +92,7 @@ struct APICCommonState {
int64_t next_time;
int idx;
QEMUTimer *timer;
+ int64_t timer_expiry;
int sipi_vector;
int wait_for_sipi;
};
@@ -115,6 +116,7 @@ extern const VMStateDescription vmstate_apic_common;
DEFINE_PROP_PTR("cpu_env", cont_type, cont_var.cpu_env)
void apic_report_irq_delivered(int delivered);
+bool apic_next_timer(APICCommonState *s, int64_t current_time);
void apic_reset_common(DeviceState *d);
int apic_init_common(SysBusDevice *d);
--
1.7.3.4
--
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