Re: [PATCH v2 2/3] acpi: tpm: Add missing device identification objects

[Michael S. Tsirkin]

On Tue, Nov 09, 2021 at 09:01:51AM -0500, 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>

Do you want this in 6.2?

> ---
>  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 674f902652..09456424aa 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -228,6 +228,7 @@ 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 a3ad6abd33..5bd2160a89 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1808,11 +1808,15 @@ 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")));


When we support more versions, won't this make us
do annoying tricks to say so in the string?
Why not just "TPM device" to future-proof it?

>                  } 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)));
>

The ACPI spec mentions also matching on _CID.

  
>                  aml_append(dev, aml_name_decl("_STA", aml_int(0xF)));
>                  crs = aml_resource_template();
> @@ -1840,6 +1844,8 @@ 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")));
>          crs = aml_resource_template();
>          aml_append(crs, aml_memory32_fixed(TPM_CRB_ADDR_BASE,
>                                             TPM_CRB_ADDR_SIZE, 
> AML_READ_WRITE));
> @@ -1847,6 +1853,8 @@ 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