[Qemu-devel] question about irq update

[Zhi Hui Li]

In the code of libqtest.c have a function :



bool qtest_get_irq(QTestState *s, int num)
{
    /* dummy operation in order to make sure irq is up to date */
    qtest_inb(s, 0);

    return s->irq_level[num];
}

but I don't know how it can make the irq up to date
and why we will read from the address of 0 ?


can anybody explain for me?
Thank you very much!