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

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 5 Jun 2023 16:39:05 -0500
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> wrote:

> 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;
> +            }

why pcms->smbios_entry_point_type that we already have is not enough
we need to add extra pcms->smbios_use_cmdline_ep_type field?

> +
>              /* 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;