Otherwise we have an unfortunate interaction with -count sleep=off which means we fast forward time when we don't need to. The easiest way to trigger it was to attach to the gdbstub and place a break point at the timers IRQ routine. Once the timer fired setting the next event at INT_MAX then qemu_start_warp_timer would skip to the end.
Signed-off-by: Alex Bennée <[email protected]> --- target/arm/helper.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index c69a2baf1d3..ec1b84cf0fd 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -2683,7 +2683,7 @@ static void gt_recalc_timer(ARMCPU *cpu, int timeridx) uint64_t count = gt_get_countervalue(&cpu->env); /* Note that this must be unsigned 64 bit arithmetic: */ int istatus = count - offset >= gt->cval; - uint64_t nexttick; + uint64_t nexttick = 0; int irqstate; gt->ctl = deposit32(gt->ctl, 2, 1, istatus); @@ -2692,21 +2692,30 @@ static void gt_recalc_timer(ARMCPU *cpu, int timeridx) qemu_set_irq(cpu->gt_timer_outputs[timeridx], irqstate); if (istatus) { - /* Next transition is when count rolls back over to zero */ - nexttick = UINT64_MAX; + /* + * The IRQ status of the timer will persist until: + * - CVAL is changed or + * - ENABLE is changed + * + * There is no point re-arming the timer for some far + * flung future - currently it just is. + */ + timer_del(cpu->gt_timer[timeridx]); } else { /* Next transition is when we hit cval */ nexttick = gt->cval + offset; - } - /* Note that the desired next expiry time might be beyond the - * signed-64-bit range of a QEMUTimer -- in this case we just - * set the timer for as far in the future as possible. When the - * timer expires we will reset the timer for any remaining period. - */ - if (nexttick > INT64_MAX / gt_cntfrq_period_ns(cpu)) { - timer_mod_ns(cpu->gt_timer[timeridx], INT64_MAX); - } else { - timer_mod(cpu->gt_timer[timeridx], nexttick); + + /* + * It is possible the next tick is beyond the + * signed-64-bit range of a QEMUTimer but currently the + * timer system doesn't support a run time of more the 292 + * odd years so we set it to INT_MAX in this case. + */ + if (nexttick > INT64_MAX / gt_cntfrq_period_ns(cpu)) { + timer_mod_ns(cpu->gt_timer[timeridx], INT64_MAX); + } else { + timer_mod(cpu->gt_timer[timeridx], nexttick); + } } trace_arm_gt_recalc(timeridx, irqstate, nexttick); } else { -- 2.20.1
