Re: [PATCH v4 2/3] acpi: tpm: Add missing device identification objects

[Ani Sinha]

On Wed, 22 Dec 2021, Stefan Berger wrote:

> Add missing device identification objects _STR and _UID. They will appear
> as files 'description' and 'uid' under Linux sysfs.
>
> Cc: Shannon Zhao <shannon.zhaosl@gmail.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Igor Mammedov <imammedo@redhat.com>
> Cc: Ani Sinha <ani@anisinha.ca>
> Fixes: https://gitlab.com/qemu-project/qemu/-/issues/708
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

Reviewed-by: Ani Sinha <ani@anisinha.ca>

> Message-id: 20211110133559.3370990-3-stefanb@linux.ibm.com
> ---
>  hw/arm/virt-acpi-build.c | 1 +
>  hw/i386/acpi-build.c     | 8 ++++++++
>  2 files changed, 9 insertions(+)
>
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index d0f4867fdf..f2514ce77c 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -229,6 +229,7 @@ static void acpi_dsdt_add_tpm(Aml *scope, 
> VirtMachineState *vms)
>
>      Aml *dev = aml_device("TPM0");
>      aml_append(dev, aml_name_decl("_HID", aml_string("MSFT0101")));
> +    aml_append(dev, aml_name_decl("_STR", aml_string("TPM 2.0 Device")));
>      aml_append(dev, aml_name_decl("_UID", aml_int(0)));
>
>      Aml *crs = aml_resource_template();
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 8383b83ee3..2fb70847cb 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1812,11 +1812,15 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>                      dev = aml_device("TPM");
>                      aml_append(dev, aml_name_decl("_HID",
>                                                    aml_string("MSFT0101")));
> +                    aml_append(dev,
> +                               aml_name_decl("_STR",
> +                                             aml_string("TPM 2.0 Device")));
>                  } else {
>                      dev = aml_device("ISA.TPM");
>                      aml_append(dev, aml_name_decl("_HID",
>                                                    aml_eisaid("PNP0C31")));
>                  }
> +                aml_append(dev, aml_name_decl("_UID", aml_int(1)));
>
>                  aml_append(dev, aml_name_decl("_STA", aml_int(0xF)));
>                  crs = aml_resource_template();
> @@ -1844,6 +1848,8 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>      if (TPM_IS_CRB(tpm)) {
>          dev = aml_device("TPM");
>          aml_append(dev, aml_name_decl("_HID", aml_string("MSFT0101")));
> +        aml_append(dev, aml_name_decl("_STR",
> +                                      aml_string("TPM 2.0 Device")));

Should we put a check here to make sure it is a 2.0 version like the code
hunk above for TIS_ISA? I looked around and it seems CRB is only
available for TPM
2.0 in which case it is probably ok but still making sure.

https://qemu.readthedocs.io/en/latest/specs/tpm.html


>          crs = aml_resource_template();
>          aml_append(crs, aml_memory32_fixed(TPM_CRB_ADDR_BASE,
>                                             TPM_CRB_ADDR_SIZE, 
> AML_READ_WRITE));
> @@ -1851,6 +1857,8 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
>
>          aml_append(dev, aml_name_decl("_STA", aml_int(0xf)));
>
> +        aml_append(dev, aml_name_decl("_UID", aml_int(1)));
> +
>          tpm_build_ppi_acpi(tpm, dev);
>
>          aml_append(sb_scope, dev);
> --
> 2.31.1
>
>