Re: [PATCH v6 1/2] hw/i386/pc: Default to use SMBIOS 3.0 for newer machine models

[Igor Mammedov <imammedo@redhat.com>]

On Fri, 23 Jun 2023 06:05:28 -0400
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> On Wed, Jun 07, 2023 at 03:57:16PM -0500, Suravee Suthikulpanit 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"
> > 
> > Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>  
> 
> For some reason this causes a diff in ACPI:
> 
> $ diff -u /tmp/asl-WQRZ61.dsl /tmp/asl-S25X61.dsl 
> --- /tmp/asl-WQRZ61.dsl 2023-06-23 05:37:54.067525946 -0400
> +++ /tmp/asl-S25X61.dsl 2023-06-23 05:37:54.073525987 -0400
> @@ -5,13 +5,13 @@
>   * 
>   * Disassembling to symbolic ASL+ operators
>   *
> - * Disassembly of /tmp/aml-IROZ61, Fri Jun 23 05:37:54 2023
> + * Disassembly of tests/data/acpi/q35/SSDT.dimmpxm, Fri Jun 23 05:37:54 2023
>   *
>   * Original Table Header:
>   *     Signature        "SSDT"
>   *     Length           0x00000717 (1815)
>   *     Revision         0x01
> - *     Checksum         0xBC
> + *     Checksum         0xAC
>   *     OEM ID           "BOCHS "
>   *     OEM Table ID     "NVDIMM"
>   *     OEM Revision     0x00000001 (1)
> @@ -389,6 +389,6 @@
>          }
>      }
>  
> -    Name (MEMA, 0x07FFE000)
> +    Name (MEMA, 0x07FFF000)
>  }
>  
> 
> Igor, any idea why?

It should be due to smbios tables size difference, which causes ACPI blob
allocated differently => different patched pointer. 

one can verify by adding '-machine  smbios-entry-point-type=64'
to test_acpi_tcg_dimm_pxm()

> 
> 
> > ---
> >  hw/i386/pc.c         | 4 +++-
> >  hw/i386/pc_piix.c    | 5 +++++
> >  hw/i386/pc_q35.c     | 5 +++++
> >  include/hw/i386/pc.h | 1 +
> >  4 files changed, 14 insertions(+), 1 deletion(-)
> > 
> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > index bb62c994fa..33ffb03a32 100644
> > --- a/hw/i386/pc.c
> > +++ b/hw/i386/pc.c
> > @@ -1853,6 +1853,7 @@ static void pc_machine_set_max_fw_size(Object *obj, Visitor *v,
> >  static void pc_machine_initfn(Object *obj)
> >  {
> >      PCMachineState *pcms = PC_MACHINE(obj);
> > +    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
> >  
> >  #ifdef CONFIG_VMPORT
> >      pcms->vmport = ON_OFF_AUTO_AUTO;
> > @@ -1860,7 +1861,7 @@ static void pc_machine_initfn(Object *obj)
> >      pcms->vmport = ON_OFF_AUTO_OFF;
> >  #endif /* CONFIG_VMPORT */
> >      pcms->max_ram_below_4g = 0; /* use default */
> > -    pcms->smbios_entry_point_type = SMBIOS_ENTRY_POINT_TYPE_32;
> > +    pcms->smbios_entry_point_type = pcmc->default_smbios_ep_type;
> >  
> >      /* acpi build is enabled by default if machine supports it */
> >      pcms->acpi_build_enabled = PC_MACHINE_GET_CLASS(pcms)->has_acpi_build;
> > @@ -1980,6 +1981,7 @@ 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 d5b0dcd1fe..49462b0e29 100644
> > --- a/hw/i386/pc_piix.c
> > +++ b/hw/i386/pc_piix.c
> > @@ -476,11 +476,16 @@ 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 6155427e48..6b9fd4d537 100644
> > --- a/hw/i386/pc_q35.c
> > +++ b/hw/i386/pc_q35.c
> > @@ -387,10 +387,15 @@ 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..6eec0fc51d 100644
> > --- a/include/hw/i386/pc.h
> > +++ b/include/hw/i386/pc.h
> > @@ -110,6 +110,7 @@ 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  
>