From: Jan Beulich <jbeulich@suse.com>
Date: Fri, 27 Jul 2012 10:22:13 +0000 (+0200)
Subject: x86: fix off-by-one in nr_irqs_gsi calculation
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~8115
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=62a2e72600271b2426c7198abb4165a3703cf8a6;p=xen.git

x86: fix off-by-one in nr_irqs_gsi calculation

highest_gsi() returns the last valid GSI, not a count.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Joe Jin <joe.jin@oracle.com>
Acked-by: Keir Fraser <keir@xen.org>
---

diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index d213f2c388..85191e0af2 100644
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -2531,7 +2531,7 @@ void __init init_ioapic_mappings(void)
         }
     }
 
-    nr_irqs_gsi = max(nr_irqs_gsi, highest_gsi());
+    nr_irqs_gsi = max(nr_irqs_gsi, highest_gsi() + 1);
 
     if ( max_gsi_irqs == 0 )
         max_gsi_irqs = nr_irqs ? nr_irqs / 8 : PAGE_SIZE;