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

[Gustavo Romero]

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]++;
         } else {
             s->irq_level[irq] = false;
         }
@@ -980,6 +983,14 @@ bool qtest_get_irq(QTestState *s, int num)
     return s->irq_level[num];
 }
 
+uint64_t qtest_get_irq_trigger_counter(QTestState *s, int irq_num)
+{
+    /* dummy operation in order to make sure irq is up to date */
+    qtest_inb(s, 0);
+
+    return s->irq_trigger_counter[irq_num];
+}
+
 void qtest_module_load(QTestState *s, const char *prefix, const char *libname)
 {
     qtest_sendf(s, "module_load %s %s\n", prefix, libname);
@@ -1799,6 +1810,7 @@ QTestState *qtest_inproc_init(QTestState **s, bool log, 
const char* arch,
     qts->wstatus = 0;
     for (int i = 0; i < MAX_IRQ; i++) {
         qts->irq_level[i] = false;
+        qts->irq_trigger_counter[i] = 0;
     }
 
     qtest_client_set_rx_handler(qts, qtest_client_inproc_recv_line);
diff --git a/tests/qtest/libqtest.h b/tests/qtest/libqtest.h
index 6e3d3525bf..d1c525aea0 100644
--- a/tests/qtest/libqtest.h
+++ b/tests/qtest/libqtest.h
@@ -364,6 +364,15 @@ void qtest_module_load(QTestState *s, const char *prefix, 
const char *libname);
  */
 bool qtest_get_irq(QTestState *s, int num);
 
+/**
+ * qtest_get_irq_counter:
+ * @s: #QTestState instance to operate on.
+ * @num: Interrupt to observe.
+ *
+ * Returns: The number of times IRQ @num got triggered (raised).
+ */
+uint64_t qtest_get_irq_trigger_counter(QTestState *s, int num);
+
 /**
  * qtest_irq_intercept_in:
  * @s: #QTestState instance to operate on.
-- 
2.34.1