From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from [140.186.70.92] (port=50089 helo=eggs.gnu.org)
	by lists.gnu.org with esmtp (Exim 4.43) id 1PmRGP-0007uK-NI
	for qemu-devel@nongnu.org; Mon, 07 Feb 2011 08:36:22 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <gleb@redhat.com>) id 1PmRGN-0002RC-UK
	for qemu-devel@nongnu.org; Mon, 07 Feb 2011 08:36:20 -0500
Received: from mx1.redhat.com ([209.132.183.28]:47492)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <gleb@redhat.com>) id 1PmRGN-0002QX-NM
	for qemu-devel@nongnu.org; Mon, 07 Feb 2011 08:36:19 -0500
Received: from int-mx02.intmail.prod.int.phx2.redhat.com
	(int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12])
	by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p17DaIxd017216
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK)
	for <qemu-devel@nongnu.org>; Mon, 7 Feb 2011 08:36:18 -0500
Received: from dhcp-1-237.tlv.redhat.com (dhcp-1-237.tlv.redhat.com
	[10.35.1.237])
	by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP
	id p17DaHnb022553
	for <qemu-devel@nongnu.org>; Mon, 7 Feb 2011 08:36:18 -0500
Date: Mon, 7 Feb 2011 15:36:17 +0200
From: Gleb Natapov <gleb@redhat.com>
Message-ID: <20110207133617.GD14984@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Subject: [Qemu-devel] [PATCHv2] correctly check ppr priority during
	interrupt injection
List-Id: qemu-devel.nongnu.org
List-Unsubscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <http://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: qemu-devel@nongnu.org

TPR blocks all interrupts in a priority class, so simple "less or
equal" check is not enough.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 v1->v2:
  - much more braces

diff --git a/hw/apic.c b/hw/apic.c
index 2f8376a..218d1bb 100644
--- a/hw/apic.c
+++ b/hw/apic.c
@@ -372,19 +372,36 @@ static int apic_get_arb_pri(APICState *s)
     return 0;
 }
 
-/* signal the CPU if an irq is pending */
-static void apic_update_irq(APICState *s)
+
+/*
+ * <0 - low prio interrupt,
+ * 0  - no interrupt,
+ * >0 - interrupt number
+ */
+static int apic_irq_pending(APICState *s)
 {
     int irrv, ppr;
-    if (!(s->spurious_vec & APIC_SV_ENABLE))
-        return;
     irrv = get_highest_priority_int(s->irr);
-    if (irrv < 0)
-        return;
+    if (irrv < 0) {
+        return 0;
+    }
     ppr = apic_get_ppr(s);
-    if (ppr && (irrv & 0xf0) <= (ppr & 0xf0))
+    if (ppr && (irrv & 0xf0) <= (ppr & 0xf0)) {
+        return -1;
+    }
+
+    return irrv;
+}
+
+/* signal the CPU if an irq is pending */
+static void apic_update_irq(APICState *s)
+{
+    if (!(s->spurious_vec & APIC_SV_ENABLE)) {
         return;
-    cpu_interrupt(s->cpu_env, CPU_INTERRUPT_HARD);
+    }
+    if (apic_irq_pending(s) > 0) {
+        cpu_interrupt(s->cpu_env, CPU_INTERRUPT_HARD);
+    }
 }
 
 void apic_reset_irq_delivered(void)
@@ -590,12 +607,13 @@ int apic_get_interrupt(DeviceState *d)
     if (!(s->spurious_vec & APIC_SV_ENABLE))
         return -1;
 
-    /* XXX: spurious IRQ handling */
-    intno = get_highest_priority_int(s->irr);
-    if (intno < 0)
+    intno = apic_irq_pending(s);
+
+    if (intno == 0) {
         return -1;
-    if (s->tpr && intno <= s->tpr)
+    } else if (intno < 0) {
         return s->spurious_vec & 0xff;
+    }
     reset_bit(s->irr, intno);
     set_bit(s->isr, intno);
     apic_update_irq(s);
--
			Gleb.