[PATCH for-6.2 v2 05/11] machine: Improve the error reporting of smp parsing

[Yanan Wang]

We totally have two requirements for a valid SMP configuration:
the sum of "sockets * dies * cores * threads" must represent all
the possible cpus, i.e., max_cpus, and must include the initial
present cpus, i.e., smp_cpus.

We only need to ensure "sockets * dies * cores * threads == maxcpus"
at first and then ensure "sockets * dies * cores * threads >= cpus".
With a reasonable order of the sanity-check, we can simplify the
error reporting code.

Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
---
 hw/core/machine.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 668f0a1553..8b4d07d3fc 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -788,21 +788,6 @@ static void smp_parse(MachineState *ms, SMPConfiguration 
*config, Error **errp)
     cpus = cpus > 0 ? cpus : sockets * dies * cores * threads;
     maxcpus = maxcpus > 0 ? maxcpus : cpus;
 
-    if (sockets * dies * cores * threads < cpus) {
-        g_autofree char *dies_msg = g_strdup_printf(
-            mc->smp_dies_supported ? " * dies (%u)" : "", dies);
-        error_setg(errp, "cpu topology: "
-                   "sockets (%u)%s * cores (%u) * threads (%u) < "
-                   "smp_cpus (%u)",
-                   sockets, dies_msg, cores, threads, cpus);
-        return;
-    }
-
-    if (maxcpus < cpus) {
-        error_setg(errp, "maxcpus must be equal to or greater than smp");
-        return;
-    }
-
     if (sockets * dies * cores * threads != maxcpus) {
         g_autofree char *dies_msg = g_strdup_printf(
             mc->smp_dies_supported ? " * dies (%u)" : "", dies);
@@ -814,6 +799,16 @@ static void smp_parse(MachineState *ms, SMPConfiguration 
*config, Error **errp)
         return;
     }
 
+    if (sockets * dies * cores * threads < cpus) {
+        g_autofree char *dies_msg = g_strdup_printf(
+            mc->smp_dies_supported ? " * dies (%u)" : "", dies);
+        error_setg(errp, "Invalid CPU topology: "
+                   "sockets (%u)%s * cores (%u) * threads (%u) < "
+                   "smp_cpus (%u)",
+                   sockets, dies_msg, cores, threads, cpus);
+        return;
+    }
+
     ms->smp.cpus = cpus;
     ms->smp.sockets = sockets;
     ms->smp.dies = dies;
-- 
2.19.1