[RFC PATCH 2/6] hw/core/machine: Parse cluster cpu topology in smp_parse()

[Yanan Wang]

Function smp_parse() in hw/core/machine.c is a generic/default function
used for parsing the -smp command line. Since the new cluster parameter
has been added in struct CpuTopology, we should parse this new parameter
in the default function.

In smp_parse(), the computing logic of missing values prefers sockets over
cores over threads. And the value of clusters will be set as default 1 if
not explictly specified, so that it will not impact the parsing results of
machines that won't specify "clusters=" in -smp command line because they
just don't support it.

Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
---
 hw/core/machine.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 970046f438..dd77ad183d 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -720,33 +720,38 @@ static void smp_parse(MachineState *ms, QemuOpts *opts)
     if (opts) {
         unsigned cpus    = qemu_opt_get_number(opts, "cpus", 0);
         unsigned sockets = qemu_opt_get_number(opts, "sockets", 0);
+        unsigned clusters = qemu_opt_get_number(opts, "clusters", 1);
         unsigned cores   = qemu_opt_get_number(opts, "cores", 0);
         unsigned threads = qemu_opt_get_number(opts, "threads", 0);
 
-        /* compute missing values, prefer sockets over cores over threads */
+        /*
+         * Compute missing values, prefer sockets over cores
+         * over threads. And the value of clusters has been
+         * set as default 1 if not explicitly specified.
+         */
         if (cpus == 0 || sockets == 0) {
             cores = cores > 0 ? cores : 1;
             threads = threads > 0 ? threads : 1;
             if (cpus == 0) {
                 sockets = sockets > 0 ? sockets : 1;
-                cpus = cores * threads * sockets;
+                cpus = sockets * clusters * cores * threads;
             } else {
                 ms->smp.max_cpus =
                         qemu_opt_get_number(opts, "maxcpus", cpus);
-                sockets = ms->smp.max_cpus / (cores * threads);
+                sockets = ms->smp.max_cpus / (clusters * cores * threads);
             }
         } else if (cores == 0) {
             threads = threads > 0 ? threads : 1;
-            cores = cpus / (sockets * threads);
+            cores = cpus / (sockets * clusters * threads);
             cores = cores > 0 ? cores : 1;
         } else if (threads == 0) {
-            threads = cpus / (cores * sockets);
+            threads = cpus / (sockets * clusters * cores);
             threads = threads > 0 ? threads : 1;
-        } else if (sockets * cores * threads < cpus) {
+        } else if (sockets * clusters * cores * threads < cpus) {
             error_report("cpu topology: "
-                         "sockets (%u) * cores (%u) * threads (%u) < "
-                         "smp_cpus (%u)",
-                         sockets, cores, threads, cpus);
+                         "sockets (%u) * clusters (%u) * cores (%u) * "
+                         "threads (%u) < smp_cpus (%u)",
+                         sockets, clusters, cores, threads, cpus);
             exit(1);
         }
 
@@ -758,16 +763,17 @@ static void smp_parse(MachineState *ms, QemuOpts *opts)
             exit(1);
         }
 
-        if (sockets * cores * threads != ms->smp.max_cpus) {
+        if (sockets * clusters * cores * threads != ms->smp.max_cpus) {
             error_report("Invalid CPU topology: "
-                         "sockets (%u) * cores (%u) * threads (%u) "
-                         "!= maxcpus (%u)",
-                         sockets, cores, threads,
+                         "sockets (%u) * clusters (%u) * cores (%u) * "
+                         "threads (%u) != maxcpus (%u)",
+                         sockets, clusters, cores, threads,
                          ms->smp.max_cpus);
             exit(1);
         }
 
         ms->smp.cpus = cpus;
+        ms->smp.clusters = clusters;
         ms->smp.cores = cores;
         ms->smp.threads = threads;
         ms->smp.sockets = sockets;
-- 
2.19.1