Re: [Qemu-devel] [RFC PATCH 1/3] tpm: Implement virtual memory device for TPM PPI

[Stefan Berger]

On 01/12/2018 09:55 AM, Marc-André Lureau wrote:
> Hi
>
> On Wed, Jan 10, 2018 at 7:35 PM, Stefan Berger
> <address@hidden> wrote:
>
> >   }
> >
> >   static void tpm_tis_class_init(ObjectClass *klass, void *data)
> > diff --git a/include/hw/acpi/tpm.h b/include/hw/acpi/tpm.h
> > index 6d516c6..d9b7452 100644
> > --- a/include/hw/acpi/tpm.h
> > +++ b/include/hw/acpi/tpm.h
> > @@ -31,4 +31,10 @@
> >
> >   #define TPM2_START_METHOD_MMIO      6
> >
> > +/*
> > + * Physical Presence Interface
> > + */
> > +#define TPM_PPI_ADDR_SIZE           0x100
> > +#define TPM_PPI_ADDR_BASE           0xffff0000

I tried to extend the memory size to be able to store per opcode flags 
into this area to de-couple the ACPI code from the firmware code as far 
as possible. I ended up seeing crashes. The following comment is in SeaBIOS:

./src/fw/shadow.c:// On the emulators, the bios at 0xf0000 is also at 
0xffff0000

Following this, I am moving this base address to 0xfffe_f000 and 
extending it to 0x400 bytes. Besides that there will be a QEMU ACPI 
table with OEM 'QEMU' and oem_table_id 'CONF' for which the firmware has 
to look for. It holds the base address and the TPM version.

   Stefan