From: Peter Dinda <pdinda@northwestern.edu>
Date: Fri, 27 Jul 2012 17:16:20 +0000 (-0500)
Subject: APIC checks enabled register on irr scan
X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?a=commitdiff_plain;h=bd229a86fee7c3cc33a81986ac46186ad67c869e;p=palacios.releases.git

APIC checks enabled register on irr scan
---

diff --git a/palacios/src/devices/apic.c b/palacios/src/devices/apic.c
index 9951071..9e636b6 100644
--- a/palacios/src/devices/apic.c
+++ b/palacios/src/devices/apic.c
@@ -505,7 +505,7 @@ static void drain_irq_entries(struct apic_state * apic) {
 static int get_highest_isr(struct apic_state * apic) {
     int i = 0, j = 0;
 
-    // We iterate backwards to find the highest priority
+    // We iterate backwards to find the highest priority in-service request
     for (i = 31; i >= 0; i--) {
 	uint8_t  * svc_major = apic->int_svc_reg + i;
     
@@ -527,14 +527,15 @@ static int get_highest_isr(struct apic_state * apic) {
 static int get_highest_irr(struct apic_state * apic) {
     int i = 0, j = 0;
 
-    // We iterate backwards to find the highest priority
+    // We iterate backwards to find the highest priority enabled requested interrupt
     for (i = 31; i >= 0; i--) {
 	uint8_t  * req_major = apic->int_req_reg + i;
-    
+	uint8_t  * en_major = apic->int_en_reg + i;
+	
 	if ((*req_major) & 0xff) {
 	    for (j = 7; j >= 0; j--) {
 		uint8_t flag = 0x1 << j;
-		if ((*req_major) & flag) {
+		if ((*req_major & *en_major) & flag) {
 		    return ((i * 8) + j);
 		}
 	    }