This was an attempt to replicate a QEMU bug. However to trigger the bug you need to have an offset set in EL2 which kvm-unit-tests is unable to do. However it does exercise some more corner cases.
Bug: https://bugs.launchpad.net/bugs/1859021 Signed-off-by: Alex Bennée <[email protected]> --- arm/timer.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/arm/timer.c b/arm/timer.c index f390e8e..ae1d299 100644 --- a/arm/timer.c +++ b/arm/timer.c @@ -214,21 +214,46 @@ static void test_timer(struct timer_info *info) * still read the pending state even if it's disabled. */ set_timer_irq_enabled(info, false); + /* Verify count goes up */ + report(info->read_counter() >= now, "counter increments"); + /* Enable the timer, but schedule it for much later */ info->write_cval(later); info->write_ctl(ARCH_TIMER_CTL_ENABLE); isb(); - report(!gic_timer_pending(info), "not pending before"); + report(!gic_timer_pending(info), "not pending before 10s"); + + /* Check with a maximum possible cval */ + info->write_cval(UINT64_MAX); + isb(); + report(!gic_timer_pending(info), "not pending before UINT64_MAX"); + + /* also by setting tval */ + info->write_tval(time_10s); + isb(); + report(!gic_timer_pending(info), "not pending before 10s (via tval)"); + report_info("TVAL is %d (delta CVAL %ld) ticks", + info->read_tval(), info->read_cval() - info->read_counter()); + /* check pending once cval is before now */ info->write_cval(now - 1); isb(); report(gic_timer_pending(info), "interrupt signal pending"); + report_info("TVAL is %d ticks", info->read_tval()); /* Disable the timer again and prepare to take interrupts */ info->write_ctl(0); set_timer_irq_enabled(info, true); report(!gic_timer_pending(info), "interrupt signal no longer pending"); + /* QEMU bug when cntvoff_el2 > 0 + * https://bugs.launchpad.net/bugs/1859021 */ + info->write_ctl(ARCH_TIMER_CTL_ENABLE); + info->write_cval(UINT64_MAX); + isb(); + report(!gic_timer_pending(info), "not pending before UINT64_MAX (irqs on)"); + info->write_ctl(0); + report(test_cval_10msec(info), "latency within 10 ms"); report(info->irq_received, "interrupt received"); -- 2.20.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
