x86: Add x86 support. Rebase the change (20906/1) due to a minor conflict.

Change-Id: Ic73cca0fc6c6e5cf74f63daa6080d00aa7c392bb
Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/hw/goldfish_events_device.c b/hw/goldfish_events_device.c
index 549fe4b..afc1724 100644
--- a/hw/goldfish_events_device.c
+++ b/hw/goldfish_events_device.c
@@ -149,7 +149,23 @@ static unsigned dequeue_event(events_state *s)
     if(s->first == s->last) {
         qemu_irq_lower(s->irq);
     }
-
+#ifdef TARGET_I386
+    /*
+     * Adding the logic to handle edge-triggered interrupts for x86
+     * because the exisiting goldfish events device basically provides
+     * level-trigger interrupts only.
+     *
+     * Logic: When an event (including the type/code/value) is fetched
+     * by the driver, if there is still another event in the event
+     * queue, the goldfish event device will re-assert the IRQ so that
+     * the driver can be notified to fetch the event again.
+     */
+    else if (((s->first + 2) & (MAX_EVENTS - 1)) < s->last ||
+               (s->first & (MAX_EVENTS - 1)) > s->last) { /* if there still is an event */
+        qemu_irq_lower(s->irq);
+        qemu_irq_raise(s->irq);
+    }
+#endif
     return n;
 }