diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2019-11-17 10:28:14 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-11-19 10:02:13 +0100 |
| commit | 7a3e29b12f5afe0106a5713bb4db6e23dc66ef91 (patch) | |
| tree | ac5e365b8aa9d01c6d07b5537aaf2d20167a835e /hw/rtc | |
| parent | 3ae32adff17226bc6a5f3fd7bb9804e6779e0660 (diff) | |
mc146818rtc: fix timer interrupt reinjection again
Commit 369b41359af46bded5799c9ef8be2b641d92e043 broke timer interrupt
reinjection when there is no period change by the guest. In that
case, old_period is 0, which ends up zeroing irq_coalesced (counter of
reinjected interrupts).
The consequence is Windows 7 is unable to synchronize time via NTP.
Easily reproducible by playing a fullscreen video with cirrus and VNC.
Fix by passing s->period when periodic_timer_update is called due to
expiration of the timer. With this change, old_period == 0 only
means that the periodic timer was off.
Reported-by: Marcelo Tosatti <mtosatti@redhat.com>
Co-developed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw/rtc')
| -rw-r--r-- | hw/rtc/mc146818rtc.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/hw/rtc/mc146818rtc.c b/hw/rtc/mc146818rtc.c index 9869dc5031..74ae74bc5c 100644 --- a/hw/rtc/mc146818rtc.c +++ b/hw/rtc/mc146818rtc.c @@ -168,12 +168,14 @@ static uint32_t rtc_periodic_clock_ticks(RTCState *s) * is just due to period adjustment. */ static void -periodic_timer_update(RTCState *s, int64_t current_time, uint32_t old_period) +periodic_timer_update(RTCState *s, int64_t current_time, uint32_t old_period, bool period_change) { uint32_t period; int64_t cur_clock, next_irq_clock, lost_clock = 0; period = rtc_periodic_clock_ticks(s); + s->period = period; + if (!period) { s->irq_coalesced = 0; timer_del(s->periodic_timer); @@ -188,7 +190,7 @@ periodic_timer_update(RTCState *s, int64_t current_time, uint32_t old_period) * if the periodic timer's update is due to period re-configuration, * we should count the clock since last interrupt. */ - if (old_period) { + if (old_period && period_change) { int64_t last_periodic_clock, next_periodic_clock; next_periodic_clock = muldiv64(s->next_periodic_time, @@ -215,7 +217,6 @@ periodic_timer_update(RTCState *s, int64_t current_time, uint32_t old_period) if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { uint32_t old_irq_coalesced = s->irq_coalesced; - s->period = period; lost_clock += old_irq_coalesced * old_period; s->irq_coalesced = lost_clock / s->period; lost_clock %= s->period; @@ -245,7 +246,7 @@ static void rtc_periodic_timer(void *opaque) { RTCState *s = opaque; - periodic_timer_update(s, s->next_periodic_time, 0); + periodic_timer_update(s, s->next_periodic_time, s->period, false); s->cmos_data[RTC_REG_C] |= REG_C_PF; if (s->cmos_data[RTC_REG_B] & REG_B_PIE) { s->cmos_data[RTC_REG_C] |= REG_C_IRQF; @@ -511,7 +512,7 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, if (update_periodic_timer) { periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), - old_period); + old_period, true); } check_update_timer(s); @@ -550,7 +551,7 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, if (update_periodic_timer) { periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), - old_period); + old_period, true); } check_update_timer(s); @@ -794,6 +795,7 @@ static int rtc_post_load(void *opaque, int version_id) s->offset = 0; check_update_timer(s); } + s->period = rtc_periodic_clock_ticks(s); /* The periodic timer is deterministic in record/replay mode, * so there is no need to update it after loading the vmstate. @@ -803,7 +805,7 @@ static int rtc_post_load(void *opaque, int version_id) uint64_t now = qemu_clock_get_ns(rtc_clock); if (now < s->next_periodic_time || now > (s->next_periodic_time + get_max_clock_jump())) { - periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), 0); + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), s->period, false); } } |