KVM: x86: drop parameter validation in ioapic/pic

We validate irq pin number when routing is setup, so
code handling illegal irq # in pic and ioapic on each injection
is never called.
Drop it, replace with BUG_ON to catch out of bounds access bugs.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 19 insertions, 18 deletions

diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index ef61d52..cfb7e4d 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -197,28 +197,29 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
 	u32 old_irr;
 	u32 mask = 1 << irq;
 	union kvm_ioapic_redirect_entry entry;
-	int ret = 1;
+	int ret, irq_level;
+
+	BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
 
 	spin_lock(&ioapic->lock);
 	old_irr = ioapic->irr;
-	if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
-		int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
-						     irq_source_id, level);
-		entry = ioapic->redirtbl[irq];
-		irq_level ^= entry.fields.polarity;
-		if (!irq_level)
-			ioapic->irr &= ~mask;
-		else {
-			int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
-			ioapic->irr |= mask;
-			if ((edge && old_irr != ioapic->irr) ||
-			    (!edge && !entry.fields.remote_irr))
-				ret = ioapic_service(ioapic, irq);
-			else
-				ret = 0; /* report coalesced interrupt */
-		}
-		trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
+	irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
+					 irq_source_id, level);
+	entry = ioapic->redirtbl[irq];
+	irq_level ^= entry.fields.polarity;
+	if (!irq_level) {
+		ioapic->irr &= ~mask;
+		ret = 1;
+	} else {
+		int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
+		ioapic->irr |= mask;
+		if ((edge && old_irr != ioapic->irr) ||
+		    (!edge && !entry.fields.remote_irr))
+			ret = ioapic_service(ioapic, irq);
+		else
+			ret = 0; /* report coalesced interrupt */
 	}
+	trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
 	spin_unlock(&ioapic->lock);
 
 	return ret;