# Commit 498d73647fa17d9eb7a67d2e9bdccac6b438e559
# Date 2020-05-08 10:44:22 +0200
# Author Juergen Gross <jgross@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
cpupool: fix removing cpu from a cpupool

Commit cb563d7665f2 ("xen/sched: support core scheduling for moving
cpus to/from cpupools") introduced a regression when trying to remove
an offline cpu from a cpupool, as the system would crash in this
situation.

Fix that by testing the cpu to be online.

Fixes: cb563d7665f2 ("xen/sched: support core scheduling for moving cpus to/from cpupools")
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Dario Faggioli <dfaggioli@suse.com>

--- a/xen/common/cpupool.c
+++ b/xen/common/cpupool.c
@@ -519,6 +519,9 @@ static int cpupool_unassign_cpu(struct c
     debugtrace_printk("cpupool_unassign_cpu(pool=%d,cpu=%d)\n",
                       c->cpupool_id, cpu);
 
+    if ( !cpu_online(cpu) )
+        return -EINVAL;
+
     master_cpu = sched_get_resource_cpu(cpu);
     ret = cpupool_unassign_cpu_start(c, master_cpu);
     if ( ret )