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

[Peter Krempa]

On Wed, Jul 08, 2020 at 10:19:11 -0400, Stefan Berger wrote:
> On 7/8/20 10:10 AM, Peter Krempa wrote:
> > 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.
> 
> 
> So should I remove the existing code that already set the version to
> VIR_DOMAIN_TPM_VERSION_1_2 and move this into that other function?

Ideally yes as a refactor prior to your change. The XML parser shouldn't
really be setting defaults or validating any form of interdependance of
values.