We accept TPM version in the domain XML. However, supported
version depends on the host configuration (swtpm_setup binary)
and thus it may be tricky for users (or mgmt applications) chose
a version. Introduce machinery for reporting supported version in
domain capabilities.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 docs/formatdomaincaps.rst      | 6 ++++++
 src/conf/domain_capabilities.c | 1 +
 src/conf/domain_capabilities.h | 1 +
 3 files changed, 8 insertions(+)

diff --git a/docs/formatdomaincaps.rst b/docs/formatdomaincaps.rst
index 384b5eb7ea..a60e610c4c 100644
--- a/docs/formatdomaincaps.rst
+++ b/docs/formatdomaincaps.rst
@@ -513,6 +513,10 @@ TPM device capabilities are exposed under the ``tpm`` element. For instance:
           <value>passthrough</value>
           <value>emulator</value>
         </enum>
+        <enum name='backendVersion'>
+          <value>1.2</value>
+          <value>2.0</value>
+        </enum>
       </tpm>
       ...
     </devices>
@@ -522,6 +526,8 @@ TPM device capabilities are exposed under the ``tpm`` element. For instance:
    Options for the ``model`` attribute of the <tpm/> element.
 ``backendModel``
    Options for the ``type`` attribute of the <tpm><backend/> element.
+``backendVersion``
+   Options for the ``version`` attribute of the <tpm><backend/> element.
 
 
 Features
diff --git a/src/conf/domain_capabilities.c b/src/conf/domain_capabilities.c
index 895e8d00e8..33570a51db 100644
--- a/src/conf/domain_capabilities.c
+++ b/src/conf/domain_capabilities.c
@@ -539,6 +539,7 @@ virDomainCapsDeviceTPMFormat(virBuffer *buf,
 
     ENUM_PROCESS(tpm, model, virDomainTPMModelTypeToString);
     ENUM_PROCESS(tpm, backendModel, virDomainTPMBackendTypeToString);
+    ENUM_PROCESS(tpm, backendVersion, virDomainTPMVersionTypeToString);
 
     FORMAT_EPILOGUE(tpm);
 }
diff --git a/src/conf/domain_capabilities.h b/src/conf/domain_capabilities.h
index f2eed80b15..a526969cda 100644
--- a/src/conf/domain_capabilities.h
+++ b/src/conf/domain_capabilities.h
@@ -127,6 +127,7 @@ struct _virDomainCapsDeviceTPM {
     virTristateBool supported;
     virDomainCapsEnum model;   /* virDomainTPMModel */
     virDomainCapsEnum backendModel;   /* virDomainTPMBackendType */
+    virDomainCapsEnum backendVersion; /* virDomainTPMVersion */
 };
 
 STATIC_ASSERT_ENUM(VIR_DOMAIN_FS_DRIVER_TYPE_LAST);
-- 
2.35.1

On Tue, Jul 12, 2022 at 16:25:48 +0200, Michal Privoznik wrote:
> We accept TPM version in the domain XML. However, supported
> version depends on the host configuration (swtpm_setup binary)

s/configuration//

AFAIK it depends on the build parameters of swtpm which isn't really
user-configurable.

> and thus it may be tricky for users (or mgmt applications) chose
> a version. Introduce machinery for reporting supported version in
> domain capabilities.
> 
> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
> ---
>  docs/formatdomaincaps.rst      | 6 ++++++
>  src/conf/domain_capabilities.c | 1 +
>  src/conf/domain_capabilities.h | 1 +
>  3 files changed, 8 insertions(+)
> 
> diff --git a/docs/formatdomaincaps.rst b/docs/formatdomaincaps.rst
> index 384b5eb7ea..a60e610c4c 100644
> --- a/docs/formatdomaincaps.rst
> +++ b/docs/formatdomaincaps.rst
> @@ -513,6 +513,10 @@ TPM device capabilities are exposed under the ``tpm`` element. For instance:
>            <value>passthrough</value>
>            <value>emulator</value>
>          </enum>
> +        <enum name='backendVersion'>
> +          <value>1.2</value>
> +          <value>2.0</value>
> +        </enum>
>        </tpm>
>        ...
>      </devices>
> @@ -522,6 +526,8 @@ TPM device capabilities are exposed under the ``tpm`` element. For instance:
>     Options for the ``model`` attribute of the <tpm/> element.
>  ``backendModel``
>     Options for the ``type`` attribute of the <tpm><backend/> element.
> +``backendVersion``
> +   Options for the ``version`` attribute of the <tpm><backend/> element.

XML elements as literals; same as in 1/1.

Reviewed-by: Peter Krempa <pkrempa@redhat.com>