[PATCH] conf: Set SPAPR TPM default to 2.0 and prevent 1.2 choice

[Peter Krempa]

On Wed, Jul 08, 2020 at 09:57:56 -0400, Stefan Berger wrote:
> From: Stefan Berger <stefanb at linux.ibm.com>
> 
> The firmware (SLOF) on QEMU for ppc64 does not support TPM 1.2, so
> prevent the choice of TPM 1.2 when the SPAPR device model is chosen
> and use a default of '2.0' (TPM 2) for the backend.
> 
> Signed-off-by: Stefan Berger <stefanb at linux.ibm.com>
> ---
>  src/qemu/qemu_validate.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
> index bd7590a00a..f4d71aebf5 100644
> --- a/src/qemu/qemu_validate.c
> +++ b/src/qemu/qemu_validate.c
> @@ -3645,8 +3645,12 @@ qemuValidateDomainDeviceDefTPM(virDomainTPMDef *tpm,
>      virQEMUCapsFlags flag;
>  
>      /* TPM 1.2 and 2 are not compatible, so we choose a specific version here */
> -    if (tpm->version == VIR_DOMAIN_TPM_VERSION_DEFAULT)
> -        tpm->version = VIR_DOMAIN_TPM_VERSION_1_2;
> +    if (tpm->version == VIR_DOMAIN_TPM_VERSION_DEFAULT) {
> +        if (tpm->model == VIR_DOMAIN_TPM_MODEL_SPAPR)
> +            tpm->version = VIR_DOMAIN_TPM_VERSION_2_0;
> +        else
> +            tpm->version = VIR_DOMAIN_TPM_VERSION_1_2;
> +    }

This is the validation callback, which must not modify the config.

qemuDomainDefTPMsPostParse is the correct place. Beaware that the
function has a short-circuit condition at the beginning.

>      switch (tpm->version) {
>      case VIR_DOMAIN_TPM_VERSION_1_2:
> @@ -3658,6 +3662,12 @@ qemuValidateDomainDeviceDefTPM(virDomainTPMDef *tpm,
>                             virDomainTPMModelTypeToString(tpm->model));
>              return -1;
>          }
> +        /* TPM 1.2 + SPAPR do not work with any 'type' (backend) */
> +        if (tpm->model == VIR_DOMAIN_TPM_MODEL_SPAPR) {
> +            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                           _("TPM 1.2 is not supported with the SPAPR device model"));
> +            return -1;
> +        }

This is okay as it validates the configuration.

>          break;
>      case VIR_DOMAIN_TPM_VERSION_2_0:
>      case VIR_DOMAIN_TPM_VERSION_DEFAULT:
> -- 
> 2.17.1
>