From d2995916ea262bca40788f275c7f53f1c0a0b606 Mon Sep 17 00:00:00 2001
From: Eduardo Habkost <ehabkost@redhat.com>
Date: Tue, 18 Mar 2014 16:29:23 -0300
Subject: [PATCH] sysemu.h: Document what MAX_CPUMASK_BITS really limits

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/sysemu/sysemu.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index b90df9ada1..90f192a074 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -133,7 +133,14 @@ extern uint8_t qemu_extra_params_fw[2];
 extern QEMUClockType rtc_clock;
 
 #define MAX_NODES 64
+
+/* The following shall be true for all CPUs:
+ *   cpu->cpu_index < max_cpus <= MAX_CPUMASK_BITS
+ *
+ * Note that cpu->get_arch_id() may be larger than MAX_CPUMASK_BITS.
+ */
 #define MAX_CPUMASK_BITS 255
+
 extern int nb_numa_nodes;
 extern uint64_t node_mem[MAX_NODES];
 extern unsigned long *node_cpumask[MAX_NODES];