Re: [PATCH 09/11] tpm_tis_sysbus: fix crash when PPI is enabled

[Stefan Berger <stefanb@linux.ibm.com>]

On 7/12/23 23:51, Joelle van Dyne wrote:
> If 'ppi' property is set, then `tpm_ppi_reset` is called on reset
> which SEGFAULTs because `tpmppi->buf` is not allocated.
> 
> Signed-off-by: Joelle van Dyne <j@getutm.app>
> ---
>   hw/tpm/tpm_tis_sysbus.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/hw/tpm/tpm_tis_sysbus.c b/hw/tpm/tpm_tis_sysbus.c
> index 45e63efd63..1014d5d993 100644
> --- a/hw/tpm/tpm_tis_sysbus.c
> +++ b/hw/tpm/tpm_tis_sysbus.c
> @@ -124,6 +124,10 @@ static void tpm_tis_sysbus_realizefn(DeviceState *dev, Error **errp)
>           error_setg(errp, "'tpmdev' property is required");
>           return;
>       }
> +
> +    if (s->ppi_enabled) {
> +        sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->ppi.ram);
> +    }
>   }
> 

The tpm-tis-device doesn't work for x86_64 but for aarch64.


We have this here in this file:

     DEFINE_PROP_BOOL("ppi", TPMStateSysBus, state.ppi_enabled, false),

I don't know whether ppi would work on aarch64. It needs firmware support like in edk2.
I think the best solution is to remove this DEFINE_PROP_BOOL() and if someone wants
to enable it they would have to add firmware support and test it before re-enabling it.

    Stefan

>   static void tpm_tis_sysbus_class_init(ObjectClass *klass, void *data)