machine: Refactor smp_parse() in vl.c as MachineClass::smp_parse()

To make smp_parse() more flexible and expansive, a smp_parse function
pointer is added to MachineClass that machine types could override.

The generic smp_parse() code in vl.c is moved to hw/core/machine.c, and
become the default implementation of MachineClass::smp_parse. A PC-specific
function called pc_smp_parse() has been added to hw/i386/pc.c, which in
this patch changes nothing against the default one .

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190620054525.37188-3-like.xu@linux.intel.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/hw/core/machine.c b/hw/core/machine.c
index b35dea05bd..2be19ec0cd 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -11,6 +11,9 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/option.h"
+#include "qapi/qmp/qerror.h"
+#include "sysemu/replay.h"
 #include "qemu/units.h"
 #include "hw/boards.h"
 #include "qapi/error.h"
@@ -726,6 +729,78 @@ void machine_set_cpu_numa_node(MachineState *machine,
     }
 }
 
+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 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 */
+        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;
+            } else {
+                ms->smp.max_cpus =
+                        qemu_opt_get_number(opts, "maxcpus", cpus);
+                sockets = ms->smp.max_cpus / (cores * threads);
+            }
+        } else if (cores == 0) {
+            threads = threads > 0 ? threads : 1;
+            cores = cpus / (sockets * threads);
+            cores = cores > 0 ? cores : 1;
+        } else if (threads == 0) {
+            threads = cpus / (cores * sockets);
+            threads = threads > 0 ? threads : 1;
+        } else if (sockets * cores * threads < cpus) {
+            error_report("cpu topology: "
+                         "sockets (%u) * cores (%u) * threads (%u) < "
+                         "smp_cpus (%u)",
+                         sockets, cores, threads, cpus);
+            exit(1);
+        }
+
+        ms->smp.max_cpus =
+                qemu_opt_get_number(opts, "maxcpus", cpus);
+
+        if (ms->smp.max_cpus < cpus) {
+            error_report("maxcpus must be equal to or greater than smp");
+            exit(1);
+        }
+
+        if (sockets * cores * threads > ms->smp.max_cpus) {
+            error_report("cpu topology: "
+                         "sockets (%u) * cores (%u) * threads (%u) > "
+                         "maxcpus (%u)",
+                         sockets, cores, threads,
+                         ms->smp.max_cpus);
+            exit(1);
+        }
+
+        if (sockets * cores * threads != ms->smp.max_cpus) {
+            warn_report("Invalid CPU topology deprecated: "
+                        "sockets (%u) * cores (%u) * threads (%u) "
+                        "!= maxcpus (%u)",
+                        sockets, cores, threads,
+                        ms->smp.max_cpus);
+        }
+
+        ms->smp.cpus = cpus;
+        ms->smp.cores = cores;
+        ms->smp.threads = threads;
+    }
+
+    if (ms->smp.cpus > 1) {
+        Error *blocker = NULL;
+        error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED, "smp");
+        replay_add_blocker(blocker);
+    }
+}
+
 static void machine_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -733,6 +808,7 @@ static void machine_class_init(ObjectClass *oc, void *data)
     /* Default 128 MB as guest ram size */
     mc->default_ram_size = 128 * MiB;
     mc->rom_file_has_mr = true;
+    mc->smp_parse = smp_parse;
 
     /* numa node memory size aligned on 8MB by default.
      * On Linux, each node's border has to be 8MB aligned