[RFC PATCH v3 4/4] hw/arm/virt: Parse -smp cluster parameter in virt_smp_parse

[Yanan Wang]

There is a separate function virt_smp_parse() in hw/virt/arm.c used
to parse cpu topology for the ARM machines. So add parsing of -smp
cluster parameter in it, then total number of logical cpus will be
calculated like: max_cpus = sockets * clusters * cores * threads.

Note, we will assume multi-cluster in one socket is not supported
and default the value of clusters to 1, if it's not explicitly
specified in -smp cmdline.

Signed-off-by: Yanan Wang <wangyanan55@huawei.com>
---
 hw/arm/virt.c | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 7de822e491..678d5ef36c 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2642,8 +2642,8 @@ static int virt_kvm_type(MachineState *ms, const char 
*type_str)
  * with the -smp cmdlines when parsing them.
  *
  * We require that at least one of cpus or maxcpus must be provided.
- * Threads will default to 1 if not provided. Sockets and cores must
- * be either both provided or both not.
+ * Clusters and threads will default to 1 if they are not provided.
+ * Sockets and cores must be either both provided or both not.
  *
  * Note, if neither sockets nor cores are specified, we will calculate
  * all the missing values just like smp_parse() does, but will disable
@@ -2652,15 +2652,18 @@ static int virt_kvm_type(MachineState *ms, const char 
*type_str)
 static void virt_smp_parse(MachineState *ms, QemuOpts *opts)
 {
     VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(ms);
+    VirtMachineState *vms = VIRT_MACHINE(ms);
 
     if (opts) {
         unsigned cpus = qemu_opt_get_number(opts, "cpus", 0);
         unsigned maxcpus = qemu_opt_get_number(opts, "maxcpus", 0);
         unsigned sockets = qemu_opt_get_number(opts, "sockets", 0);
+        unsigned clusters = qemu_opt_get_number(opts, "clusters", 0);
         unsigned cores = qemu_opt_get_number(opts, "cores", 0);
         unsigned threads = qemu_opt_get_number(opts, "threads", 0);
 
-        /* Default threads to 1 if not provided */
+        /* Default clusters and threads to 1 if not provided */
+        clusters = clusters > 0 ? clusters : 1;
         threads = threads > 0 ? threads : 1;
 
         if (cpus == 0 && maxcpus == 0) {
@@ -2676,13 +2679,13 @@ static void virt_smp_parse(MachineState *ms, QemuOpts 
*opts)
             cores = 1;
             if (cpus == 0) {
                 sockets = 1;
-                cpus = sockets * cores * threads;
+                cpus = sockets * clusters * cores * threads;
             } else {
                 maxcpus = maxcpus > 0 ? maxcpus : cpus;
-                sockets = maxcpus / (cores * threads);
+                sockets = maxcpus / (clusters * cores * threads);
             }
         } else if (sockets > 0 && cores > 0) {
-            cpus = cpus > 0 ? cpus : sockets * cores * threads;
+            cpus = cpus > 0 ? cpus : sockets * clusters * cores * threads;
             maxcpus = maxcpus > 0 ? maxcpus : cpus;
         } else {
             error_report("sockets and cores must be both provided "
@@ -2695,25 +2698,26 @@ static void virt_smp_parse(MachineState *ms, QemuOpts 
*opts)
             exit(1);
         }
 
-        if (sockets * cores * threads < cpus) {
+        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);
         }
 
-        if (sockets * cores * threads != maxcpus) {
+        if (sockets * clusters * cores * threads != maxcpus) {
             error_report("cpu topology: "
-                         "sockets (%u) * cores (%u) * threads (%u) "
-                         "!= maxcpus (%u)",
-                         sockets, cores, threads, maxcpus);
+                         "sockets (%u) * clusters (%u) * cores (%u) * "
+                         "threads (%u) != maxcpus (%u)",
+                         sockets, clusters, cores, threads, maxcpus);
             exit(1);
         }
 
         ms->smp.cpus = cpus;
         ms->smp.max_cpus = maxcpus;
         ms->smp.sockets = sockets;
+        vms->smp_clusters = clusters;
         ms->smp.cores = cores;
         ms->smp.threads = threads;
     }
-- 
2.19.1