This revision is incorrect. Here is the latest one: https://lists.gnu.org/archive/html/qemu-devel/2018-01/msg01751.html
Pavel Dovgalyuk > -----Original Message----- > From: Paolo Bonzini [mailto:paolo.bonz...@gmail.com] On Behalf Of Paolo > Bonzini > Sent: Friday, January 12, 2018 2:30 PM > To: qemu-devel@nongnu.org > Cc: Maria Klimushenkova; Pavel Dovgalyuk > Subject: [PULL 04/52] hpet: recover timer offset correctly > > From: Maria Klimushenkova <maria.klimushenk...@ispras.ru> > > HPET saves its state by calculating the current time and recovers timer > offset using this calculated value. But these calculations include > divisions and multiplications. Therefore the timer state cannot be recovered > precise enough. > This patch introduces saving of the original value of the offset to > preserve the determinism of the timer. > > Signed-off-by: Maria Klimushenkova <maria.klimushenk...@ispras.ru> > Signed-off-by: Pavel Dovgalyuk <pavel.dovga...@ispras.ru> > Message-Id: <20171220100205.16625.84632.stgit@pasha-VirtualBox> > Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> > --- > hw/timer/hpet.c | 32 ++++++++++++++++++++++++++++++-- > 1 file changed, 30 insertions(+), 2 deletions(-) > > diff --git a/hw/timer/hpet.c b/hw/timer/hpet.c > index 577371b..4904a60 100644 > --- a/hw/timer/hpet.c > +++ b/hw/timer/hpet.c > @@ -70,6 +70,7 @@ typedef struct HPETState { > > MemoryRegion iomem; > uint64_t hpet_offset; > + bool hpet_offset_loaded; > qemu_irq irqs[HPET_NUM_IRQ_ROUTES]; > uint32_t flags; > uint8_t rtc_irq_level; > @@ -221,7 +222,9 @@ static int hpet_pre_save(void *opaque) > HPETState *s = opaque; > > /* save current counter value */ > - s->hpet_counter = hpet_get_ticks(s); > + if (hpet_enabled(s)) { > + s->hpet_counter = hpet_get_ticks(s); > + } > > return 0; > } > @@ -232,6 +235,8 @@ static int hpet_pre_load(void *opaque) > > /* version 1 only supports 3, later versions will load the actual value > */ > s->num_timers = HPET_MIN_TIMERS; > + /* for checking whether the hpet_offset section is loaded */ > + s->hpet_offset_loaded = false; > return 0; > } > > @@ -252,7 +257,10 @@ static int hpet_post_load(void *opaque, int version_id) > HPETState *s = opaque; > > /* Recalculate the offset between the main counter and guest time */ > - s->hpet_offset = ticks_to_ns(s->hpet_counter) - > qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); > + if (!s->hpet_offset_loaded) { > + s->hpet_offset = ticks_to_ns(s->hpet_counter) > + - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); > + } > > /* Push number of timers into capability returned via HPET_ID */ > s->capability &= ~HPET_ID_NUM_TIM_MASK; > @@ -267,6 +275,14 @@ static int hpet_post_load(void *opaque, int version_id) > return 0; > } > > +static int hpet_offset_post_load(void *opaque, int version_id) > +{ > + HPETState *s = opaque; > + > + s->hpet_offset_loaded = true; > + return 0; > +} > + > static bool hpet_rtc_irq_level_needed(void *opaque) > { > HPETState *s = opaque; > @@ -285,6 +301,17 @@ static const VMStateDescription > vmstate_hpet_rtc_irq_level = { > } > }; > > +static const VMStateDescription vmstate_hpet_offset = { > + .name = "hpet/offset", > + .version_id = 1, > + .minimum_version_id = 1, > + .post_load = hpet_offset_post_load, > + .fields = (VMStateField[]) { > + VMSTATE_UINT64(hpet_offset, HPETState), > + VMSTATE_END_OF_LIST() > + } > +}; > + > static const VMStateDescription vmstate_hpet_timer = { > .name = "hpet_timer", > .version_id = 1, > @@ -320,6 +347,7 @@ static const VMStateDescription vmstate_hpet = { > }, > .subsections = (const VMStateDescription*[]) { > &vmstate_hpet_rtc_irq_level, > + &vmstate_hpet_offset, > NULL > } > }; > -- > 1.8.3.1 >
