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>

2 files changed, 28 insertions, 27 deletions

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index e498b18f010c..90c84f947d45 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -190,17 +190,17 @@ void kvm_pic_update_irq(struct kvm_pic *s)
 
 int kvm_pic_set_irq(struct kvm_pic *s, int irq, int irq_source_id, int level)
 {
-        int ret = -1;
+        int ret, irq_level;
+
+        BUG_ON(irq < 0 || irq >= PIC_NUM_PINS);
 
         pic_lock(s);
-        if (irq >= 0 && irq < PIC_NUM_PINS) {
-                int irq_level = __kvm_irq_line_state(&s->irq_states[irq],
-                                                     irq_source_id, level);
-                ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
-                pic_update_irq(s);
-                trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
-                                      s->pics[irq >> 3].imr, ret == 0);
-        }
+        irq_level = __kvm_irq_line_state(&s->irq_states[irq],
+                                         irq_source_id, level);
+        ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, irq_level);
+        pic_update_irq(s);
+        trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,
+                              s->pics[irq >> 3].imr, ret == 0);
         pic_unlock(s);
 
         return ret;
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index ef61d529a6c4..cfb7e4d52dc2 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;