On Tue, Apr 21, 2026 at 11:08:47 +0530, Srihari Parimi via Devel wrote:
> Parses vtpm.present from VMX files and converts to libvirt TPM
> device with CRB model and emulator backend. VMware vTPM uses
> TPM 2.0 as specified in the document below
>
> https://techdocs.broadcom.com/us/en/vmware-cis/vsphere/vsphere/8-0/vsphere-security/securing-virtual-machines-with-virtual-trusted-platform-module/vtpm-overview.html
>
> Default to the CRB interface for TPM 2.0 systems to improve
> performance and follow industry standards over legacy TIS.

So what this patch does is to parse presence of the vTPM and represent
it in the XML. It doesn't set any default or anything, just represents
what the VM has configured.

So what is the sentence above trying to state?


>
> Signed-off-by: Srihari Parimi <sparimi@redhat.com>
> ---
>  src/vmx/vmx.c              | 31 +++++++++++++++++++++++++++++++
>  tests/vmx2xmldata/vtpm.vmx | 22 ++++++++++++++++++++++
>  tests/vmx2xmldata/vtpm.xml | 32 ++++++++++++++++++++++++++++++++
>  tests/vmx2xmltest.c        |  2 ++
>  4 files changed, 87 insertions(+)
>  create mode 100644 tests/vmx2xmldata/vtpm.vmx
>  create mode 100644 tests/vmx2xmldata/vtpm.xml
>
> diff --git a/src/vmx/vmx.c b/src/vmx/vmx.c
> index 57dfd57cfc..bec985aef3 100644
> --- a/src/vmx/vmx.c
> +++ b/src/vmx/vmx.c
> @@ -599,6 +599,7 @@ static int virVMXParseSerial(virVMXContext *ctx, virConf *conf, int port,
>  static int virVMXParseParallel(virVMXContext *ctx, virConf *conf, int port,
>                                 virDomainChrDef **def);
>  static int virVMXParseSVGA(virConf *conf, virDomainVideoDef **def);
> +static int virVMXParseTPM(virConf *conf, virDomainTPMDef **def);
> 
>  static int virVMXFormatVNC(virDomainGraphicsDef *def, virBuffer *buffer);
>  static int virVMXFormatDisk(virVMXContext *ctx, virDomainDiskDef *def,
> @@ -1938,6 +1939,15 @@ virVMXParseConfig(virVMXContext *ctx,
> 
>      def->nvideos = 1;
> 
> +    /* def:tpms */
> +    {
> +        virDomainTPMDef *tpm = NULL;
> +        if (virVMXParseTPM(conf, &tpm) < 0)
> +            goto cleanup;
> +        if (tpm)
> +            VIR_APPEND_ELEMENT(def->tpms, def->ntpms, tpm);
> +    }
> +
>      /* def:sounds */
>      /* FIXME */
> 
> @@ -3367,6 +3377,27 @@ virVMXParseSVGA(virConf *conf, virDomainVideoDef **def)
>      return result;
>  }
> 
> +static int
> +virVMXParseTPM(virConf *conf, virDomainTPMDef **def)
> +{
> +    bool vtpm_present = false;
> +
> +    /* vmx:vtpm.present */
> +    if (virVMXGetConfigBoolean(conf, "vtpm.present", &vtpm_present,
> +                               false, true) < 0) {
> +        return -1;
> +    }
> +
> +    if (!vtpm_present)
> +        return 0;
> +
> +    *def = g_new0(virDomainTPMDef, 1);
> +    (*def)->type = VIR_DOMAIN_TPM_TYPE_EMULATOR;
> +    (*def)->model = VIR_DOMAIN_TPM_MODEL_CRB;
> +    (*def)->data.emulator.version = VIR_DOMAIN_TPM_VERSION_2_0;
> +
> +    return 0;
> +}
> 
> 


In other recent patch adding 'nvram' config to vmx I've noticed that
also virVMXFormatConfig is changed.

I wonder if the VMX driver needs something similar for the vTPM.
Although that will require some validation and I don't see that the VMX
driver implements the validation callbacks which would make adding the
validation much simpler.

I think that this patch can be merged as-is (minus the last sentence of
the commit message), but depends on what you want to do about the
formatter.