xen: Infrastructure to allow irqs to share vector maps

Laying the groundwork for per-device vector maps.  This generic
code allows any irq to point to a vector map; all irqs sharing the
same vector map will avoid sharing vectors.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/xen/arch/x86/io_apic.c b/xen/arch/x86/io_apic.c
index 908915a4db..258f341c25 100644
--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -449,6 +449,11 @@ fastcall void smp_irq_move_cleanup_interrupt(struct cpu_user_regs *regs)
                  irq, vector, smp_processor_id());
 
         __get_cpu_var(vector_irq)[vector] = -1;
+        if ( cfg->used_vectors )
+        {
+            ASSERT(test_bit(vector, cfg->used_vectors));
+            clear_bit(vector, cfg->used_vectors);
+        }
         cfg->move_cleanup_count--;
 unlock:
         spin_unlock(&desc->lock);