[RFC PATCH 06/12] core/irq: add qemu_irq_remove_intercept interface

[Heyi Guo <guoheyi@huawei.com>]

We use qemu_irq as the bridge for other qemu modules to switch from
irq injection to SDEI event trigger after VM binds the interrupt to
SDEI event. We use qemu_irq_intercept_in() to override qemu_irq
handler with SDEI event trigger, so we also need a corresponding
interface to restore the handler to default one (i.e. ARM GIC).

qemu_irq_remove_intercept() is the new interface to do the above
job.

Signed-off-by: Heyi Guo <guoheyi@huawei.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
---
 hw/core/irq.c    | 11 +++++++++++
 include/hw/irq.h |  8 ++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/hw/core/irq.c b/hw/core/irq.c
index 7cc0295..114bce6 100644
--- a/hw/core/irq.c
+++ b/hw/core/irq.c
@@ -145,6 +145,17 @@ void qemu_irq_intercept_in(qemu_irq *gpio_in, qemu_irq_handler handler, int n)
     }
 }
 
+void qemu_irq_remove_intercept(qemu_irq *gpio_in, int n)
+{
+    int i;
+    qemu_irq *old_irqs = gpio_in[0]->opaque;
+    for (i = 0; i < n; i++) {
+        gpio_in[i]->handler = old_irqs[i]->handler;
+        gpio_in[i]->opaque = old_irqs[i]->opaque;
+    }
+    qemu_free_irqs(old_irqs, n);
+}
+
 static const TypeInfo irq_type_info = {
    .name = TYPE_IRQ,
    .parent = TYPE_OBJECT,
diff --git a/include/hw/irq.h b/include/hw/irq.h
index fe527f6..1af1db9 100644
--- a/include/hw/irq.h
+++ b/include/hw/irq.h
@@ -56,8 +56,12 @@ qemu_irq qemu_irq_split(qemu_irq irq1, qemu_irq irq2);
  */
 qemu_irq *qemu_irq_proxy(qemu_irq **target, int n);
 
-/* For internal use in qtest.  Similar to qemu_irq_split, but operating
-   on an existing vector of qemu_irq.  */
+/*
+ * Similar to qemu_irq_split, but operating on an existing vector of qemu_irq.
+ */
 void qemu_irq_intercept_in(qemu_irq *gpio_in, qemu_irq_handler handler, int n);
 
+/* Restore the irq handler intercepted by qemu_irq_intercept_in() */
+void qemu_irq_remove_intercept(qemu_irq *gpio_in, int n);
+
 #endif
-- 
1.8.3.1