From fa834e919788dfa0965495f21760eb38fe480342 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@redhat.com>
Date: Thu, 27 Nov 2014 20:03:12 +0100
Subject: [PATCH] KVM: x86: fix APIC physical destination wrapping
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x2apic allows destinations > 0xff and we don't want them delivered to
lower APICs.  They are correctly handled by doing nothing.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/lapic.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 541e17865e63..bd82054664fd 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -693,7 +693,10 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
 	ret = true;
 
 	if (irq->dest_mode == 0) { /* physical mode */
-		dst = &map->phys_map[irq->dest_id & 0xff];
+		if (irq->dest_id >= ARRAY_SIZE(map->phys_map))
+			goto out;
+
+		dst = &map->phys_map[irq->dest_id];
 	} else {
 		u32 mda = irq->dest_id << (32 - map->ldr_bits);
 
-- 
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