[PATCH v4 2/3] hw/i386/pc: Default to use SMBIOS 3.0 for newer machine models

[Suravee Suthikulpanit]

Currently, pc-q35 and pc-i44fx machine models are default to use SMBIOS 2.8
(32-bit entry point). Since SMBIOS 3.0 (64-bit entry point) is now fully
supported since QEMU 7.0, default to use SMBIOS 3.0 for newer machine
models. This is necessary to avoid the following message when launching
a VM with large number of vcpus.

   "SMBIOS 2.1 table length 66822 exceeds 65535"

Note that user can still override the entry point tyme w/ QEMU option
"-M ..., smbios-entry-point-type=[32|64].

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
 hw/i386/pc.c         | 14 +++++++++++++-
 hw/i386/pc_piix.c    |  5 +++++
 hw/i386/pc_q35.c     |  5 +++++
 include/hw/i386/pc.h |  2 ++
 4 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 8fc34f5454..5a87b82185 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -786,6 +786,14 @@ void pc_machine_done(Notifier *notifier, void *data)
         if (pcmc->smbios_defaults) {
             MachineClass *mc = MACHINE_GET_CLASS(pcms);
 
+            /*
+             * Check if user has specified a command line option
+             * to override the SMBIOS default entry point type.
+             */
+            if (!pcms->smbios_use_cmdline_ep_type) {
+                pcms->smbios_entry_point_type = pcmc->default_smbios_ep_type;
+            }
+
             /* These values are guest ABI, do not change */
             smbios_set_defaults("QEMU", mc->desc,
                                 mc->name, pcmc->smbios_legacy_mode,
@@ -1782,7 +1790,10 @@ static void pc_machine_set_smbios_ep(Object *obj, 
Visitor *v, const char *name,
 {
     PCMachineState *pcms = PC_MACHINE(obj);
 
-    visit_type_SmbiosEntryPointType(v, name, &pcms->smbios_entry_point_type, 
errp);
+    pcms->smbios_use_cmdline_ep_type =
+        visit_type_SmbiosEntryPointType(v, name,
+                                        &pcms->smbios_entry_point_type,
+                                        errp);
 }
 
 static void pc_machine_get_max_ram_below_4g(Object *obj, Visitor *v,
@@ -1992,6 +2003,7 @@ static void pc_machine_class_init(ObjectClass *oc, void 
*data)
     mc->nvdimm_supported = true;
     mc->smp_props.dies_supported = true;
     mc->default_ram_id = "pc.ram";
+    pcmc->default_smbios_ep_type = SMBIOS_ENTRY_POINT_TYPE_64;
 
     object_class_property_add(oc, PC_MACHINE_MAX_RAM_BELOW_4G, "size",
         pc_machine_get_max_ram_below_4g, pc_machine_set_max_ram_below_4g,
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index da6ba4eeb4..1a2bb25c75 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -467,11 +467,16 @@ DEFINE_I440FX_MACHINE(v8_1, "pc-i440fx-8.1", NULL,
 
 static void pc_i440fx_8_0_machine_options(MachineClass *m)
 {
+    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
+
     pc_i440fx_8_1_machine_options(m);
     m->alias = NULL;
     m->is_default = false;
     compat_props_add(m->compat_props, hw_compat_8_0, hw_compat_8_0_len);
     compat_props_add(m->compat_props, pc_compat_8_0, pc_compat_8_0_len);
+
+    /* For pc-i44fx-8.0 and older, use SMBIOS 2.8 by default */
+    pcmc->default_smbios_ep_type = SMBIOS_ENTRY_POINT_TYPE_32;
 }
 
 DEFINE_I440FX_MACHINE(v8_0, "pc-i440fx-8.0", NULL,
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index a58cd1d3ea..371cca7484 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -379,10 +379,15 @@ DEFINE_Q35_MACHINE(v8_1, "pc-q35-8.1", NULL,
 
 static void pc_q35_8_0_machine_options(MachineClass *m)
 {
+    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
+
     pc_q35_8_1_machine_options(m);
     m->alias = NULL;
     compat_props_add(m->compat_props, hw_compat_8_0, hw_compat_8_0_len);
     compat_props_add(m->compat_props, pc_compat_8_0, pc_compat_8_0_len);
+
+    /* For pc-q35-8.0 and older, use SMBIOS 2.8 by default */
+    pcmc->default_smbios_ep_type = SMBIOS_ENTRY_POINT_TYPE_32;
 }
 
 DEFINE_Q35_MACHINE(v8_0, "pc-q35-8.0", NULL,
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index c661e9cc80..f754da5a38 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -50,6 +50,7 @@ typedef struct PCMachineState {
     bool i8042_enabled;
     bool default_bus_bypass_iommu;
     uint64_t max_fw_size;
+    bool smbios_use_cmdline_ep_type;
 
     /* ACPI Memory hotplug IO base address */
     hwaddr memhp_io_base;
@@ -110,6 +111,7 @@ struct PCMachineClass {
     bool smbios_defaults;
     bool smbios_legacy_mode;
     bool smbios_uuid_encoded;
+    SmbiosEntryPointType default_smbios_ep_type;
 
     /* RAM / address space compat: */
     bool gigabyte_align;
-- 
2.34.1