[Qemu-devel] [PATCH v4 1/1] numa: Print warning if no node is assigned to a CPU

[Eduardo Habkost]

Instead of silently assigning CPU to node 0 when it is omitted from the
command-line, check if all CPUs up to max_cpus are present in the NUMA
configuration.

I am making this a warning and not a fatal error, to allow management
software to be updated if necessary.

Signed-off-by: Eduardo Habkost <address@hidden>
---
v1 -> v2: (no changes)

v2 -> v3:
 * Use enumerate_cpus() and error_report() for error message
 * Simplify logic using bitmap_full()

v3 -> v4:
 * Clarify error message, mention that all CPUs up to
   maxcpus need to be described in NUMA config
---
 numa.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/numa.c b/numa.c
index 9a3fc15..d8021b9 100644
--- a/numa.c
+++ b/numa.c
@@ -201,6 +201,16 @@ static void validate_numa_cpus(void)
         bitmap_or(seen_cpus, seen_cpus,
                   numa_info[i].node_cpu, MAX_CPUMASK_BITS);
     }
+
+    if (!bitmap_full(seen_cpus, max_cpus)) {
+        char *msg;
+        bitmap_complement(seen_cpus, seen_cpus, max_cpus);
+        msg = enumerate_cpus(seen_cpus, max_cpus);
+        error_report("warning: CPU(s) not present in any NUMA nodes: %s", msg);
+        error_report("warning: All CPU(s) up to maxcpus should be described "
+                     "in NUMA config");
+        g_free(msg);
+    }
 }
 
 void parse_numa_opts(void)
-- 
2.1.0