From 091831633f91009379ff9daf2dc98f917aefa12f Mon Sep 17 00:00:00 2001
From: Guannan Ren <gren@redhat.com>
Date: Wed, 20 Feb 2013 19:28:13 +0800
Subject: [PATCH] qemu: fix an off-by-one error in qemuDomainGetPercpuStats

The max value of number of cpus to compute(id) should not
be equal or greater than max cpu number.
The bug ocurrs when id value is equal to max cpu number which
leads to the off-by-one error in the following for loop.

 # virsh  cpu-stats guest --start 1
 error: Failed to virDomainGetCPUStats()

 error: internal error cpuacct parse error
---
 src/qemu/qemu_driver.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 45bd341599..e4ace30125 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -14331,9 +14331,9 @@ qemuDomainGetPercpuStats(virDomainObjPtr vm,
     param_idx = 0;
 
     /* number of cpus to compute */
-    id = max_id;
-
-    if (max_id - start_cpu > ncpus - 1)
+    if (start_cpu >= max_id - ncpus)
+        id = max_id - 1;
+    else
         id = start_cpu + ncpus - 1;
 
     for (i = 0; i <= id; i++) {
-- 
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