[Qemu-devel] [PULL 29/29] vl.c: Add -smp, dies=* command line support and update doc

[Eduardo Habkost <ehabkost@redhat.com>]

From: Like Xu <like.xu@linux.intel.com>

For PC target, users could configure the number of dies per one package
via command line with this patch, such as "-smp dies=2,cores=4".

The parsing rules of new cpu-topology model obey the same restrictions/logic
as the legacy socket/core/thread model especially on missing values computing.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
Message-Id: <20190620054525.37188-4-like.xu@linux.intel.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
 hw/i386/pc.c    | 30 +++++++++++++++++-------------
 vl.c            |  3 +++
 qemu-options.hx | 17 +++++++++--------
 3 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index b9c25bed35..3f0f221a5b 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1545,9 +1545,12 @@ static void pc_new_cpu(PCMachineState *pcms, int64_t apic_id, Error **errp)
  */
 void pc_smp_parse(MachineState *ms, QemuOpts *opts)
 {
+    PCMachineState *pcms = PC_MACHINE(ms);
+
     if (opts) {
         unsigned cpus    = qemu_opt_get_number(opts, "cpus", 0);
         unsigned sockets = qemu_opt_get_number(opts, "sockets", 0);
+        unsigned dies = qemu_opt_get_number(opts, "dies", 1);
         unsigned cores   = qemu_opt_get_number(opts, "cores", 0);
         unsigned threads = qemu_opt_get_number(opts, "threads", 0);
 
@@ -1557,24 +1560,24 @@ void pc_smp_parse(MachineState *ms, QemuOpts *opts)
             threads = threads > 0 ? threads : 1;
             if (cpus == 0) {
                 sockets = sockets > 0 ? sockets : 1;
-                cpus = cores * threads * sockets;
+                cpus = cores * threads * dies * sockets;
             } else {
                 ms->smp.max_cpus =
                         qemu_opt_get_number(opts, "maxcpus", cpus);
-                sockets = ms->smp.max_cpus / (cores * threads);
+                sockets = ms->smp.max_cpus / (cores * threads * dies);
             }
         } else if (cores == 0) {
             threads = threads > 0 ? threads : 1;
-            cores = cpus / (sockets * threads);
+            cores = cpus / (sockets * dies * threads);
             cores = cores > 0 ? cores : 1;
         } else if (threads == 0) {
-            threads = cpus / (cores * sockets);
+            threads = cpus / (cores * dies * sockets);
             threads = threads > 0 ? threads : 1;
-        } else if (sockets * cores * threads < cpus) {
+        } else if (sockets * dies * cores * threads < cpus) {
             error_report("cpu topology: "
-                         "sockets (%u) * cores (%u) * threads (%u) < "
+                         "sockets (%u) * dies (%u) * cores (%u) * threads (%u) < "
                          "smp_cpus (%u)",
-                         sockets, cores, threads, cpus);
+                         sockets, dies, cores, threads, cpus);
             exit(1);
         }
 
@@ -1586,26 +1589,27 @@ void pc_smp_parse(MachineState *ms, QemuOpts *opts)
             exit(1);
         }
 
-        if (sockets * cores * threads > ms->smp.max_cpus) {
+        if (sockets * dies * cores * threads > ms->smp.max_cpus) {
             error_report("cpu topology: "
-                         "sockets (%u) * cores (%u) * threads (%u) > "
+                         "sockets (%u) * dies (%u) * cores (%u) * threads (%u) > "
                          "maxcpus (%u)",
-                         sockets, cores, threads,
+                         sockets, dies, cores, threads,
                          ms->smp.max_cpus);
             exit(1);
         }
 
-        if (sockets * cores * threads != ms->smp.max_cpus) {
+        if (sockets * dies * cores * threads != ms->smp.max_cpus) {
             warn_report("Invalid CPU topology deprecated: "
-                        "sockets (%u) * cores (%u) * threads (%u) "
+                        "sockets (%u) * dies (%u) * cores (%u) * threads (%u) "
                         "!= maxcpus (%u)",
-                        sockets, cores, threads,
+                        sockets, dies, cores, threads,
                         ms->smp.max_cpus);
         }
 
         ms->smp.cpus = cpus;
         ms->smp.cores = cores;
         ms->smp.threads = threads;
+        pcms->smp_dies = dies;
     }
 
     if (ms->smp.cpus > 1) {
diff --git a/vl.c b/vl.c
index f6e591b80c..23fe3e753b 100644
--- a/vl.c
+++ b/vl.c
@@ -1233,6 +1233,9 @@ static QemuOptsList qemu_smp_opts = {
         }, {
             .name = "sockets",
             .type = QEMU_OPT_NUMBER,
+        }, {
+            .name = "dies",
+            .type = QEMU_OPT_NUMBER,
         }, {
             .name = "cores",
             .type = QEMU_OPT_NUMBER,
diff --git a/qemu-options.hx b/qemu-options.hx
index 0d8beb4afd..a5b314a448 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -138,25 +138,26 @@ no incompatible TCG features have been enabled (e.g. icount/replay).
 ETEXI
 
 DEF("smp", HAS_ARG, QEMU_OPTION_smp,
-    "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,sockets=sockets]\n"
+    "-smp [cpus=]n[,maxcpus=cpus][,cores=cores][,threads=threads][,dies=dies][,sockets=sockets]\n"
     "                set the number of CPUs to 'n' [default=1]\n"
     "                maxcpus= maximum number of total cpus, including\n"
     "                offline CPUs for hotplug, etc\n"
-    "                cores= number of CPU cores on one socket\n"
+    "                cores= number of CPU cores on one socket (for PC, it's on one die)\n"
     "                threads= number of threads on one CPU core\n"
+    "                dies= number of CPU dies on one socket (for PC only)\n"
     "                sockets= number of discrete sockets in the system\n",
         QEMU_ARCH_ALL)
 STEXI
-@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
+@item -smp [cpus=]@var{n}[,cores=@var{cores}][,threads=@var{threads}][,dies=dies][,sockets=@var{sockets}][,maxcpus=@var{maxcpus}]
 @findex -smp
 Simulate an SMP system with @var{n} CPUs. On the PC target, up to 255
 CPUs are supported. On Sparc32 target, Linux limits the number of usable CPUs
 to 4.
-For the PC target, the number of @var{cores} per socket, the number
-of @var{threads} per cores and the total number of @var{sockets} can be
-specified. Missing values will be computed. If any on the three values is
-given, the total number of CPUs @var{n} can be omitted. @var{maxcpus}
-specifies the maximum number of hotpluggable CPUs.
+For the PC target, the number of @var{cores} per die, the number of @var{threads}
+per cores, the number of @var{dies} per packages and the total number of
+@var{sockets} can be specified. Missing values will be computed.
+If any on the three values is given, the total number of CPUs @var{n} can be omitted.
+@var{maxcpus} specifies the maximum number of hotpluggable CPUs.
 ETEXI
 
 DEF("numa", HAS_ARG, QEMU_OPTION_numa,
-- 
2.18.0.rc1.1.g3f1ff2140