Re: [PATCH] test/qtest: Add an API function to capture IRQ toggling

[Thomas Huth <thuth@redhat.com>]

On 12/11/2023 02.38, Gustavo Romero wrote:
> Currently the QTest API does not provide a function to allow capturing
> when an IRQ line is toggled (raised then lowered). Functions like
> qtest_get_irq() read the current state of the intercepted IRQ lines,
> which is already low when the function is called, since the line is
> toggled.
> 
> This commit introduces a new function, qtest_get_irq_trigger_counter(),
> which returns the number of times a given intercepted IRQ line was
> triggered (raised), hence allowing to capture when an IRQ line was
> toggled.
> 
> Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
> ---
>   tests/qtest/libqtest.c | 12 ++++++++++++
>   tests/qtest/libqtest.h |  9 +++++++++
>   2 files changed, 21 insertions(+)
> 
> diff --git a/tests/qtest/libqtest.c b/tests/qtest/libqtest.c
> index f33a210861..21891b52f1 100644
> --- a/tests/qtest/libqtest.c
> +++ b/tests/qtest/libqtest.c
> @@ -82,6 +82,7 @@ struct QTestState
>       int expected_status;
>       bool big_endian;
>       bool irq_level[MAX_IRQ];
> +    uint64_t irq_trigger_counter[MAX_IRQ];
>       GString *rx;
>       QTestTransportOps ops;
>       GList *pending_events;
> @@ -498,6 +499,7 @@ static QTestState *qtest_init_internal(const char *qemu_bin,
>       s->rx = g_string_new("");
>       for (i = 0; i < MAX_IRQ; i++) {
>           s->irq_level[i] = false;
> +        s->irq_trigger_counter[i] = 0;
>       }
>   
>       /*
> @@ -690,6 +692,7 @@ redo:
>   
>           if (strcmp(words[1], "raise") == 0) {
>               s->irq_level[irq] = true;
> +            s->irq_trigger_counter[irq]++;

Not sure whether you can get some "raise" events in a row without some 
"lower" events in between ... but just in case, I wonder whether it would 
make sense to check whether it is really a rising edge, i.e.:

            if (strcmp(words[1], "raise") == 0) {
                if (!s->irq_level[irq]) {
                    s->irq_trigger_counter[irq]++;
                }
                s->irq_level[irq] = true;

What do you think?

>           } else {
>               s->irq_level[irq] = false;
>           }

Anyway:
Acked-by: Thomas Huth <thuth@redhat.com>