On Wed, 9 Jan 2019 23:31:14 +0400
Marc-André Lureau <marcandre.lur...@redhat.com> wrote:
> The interface is described in the "TCG Platform Reset Attack
> Mitigation Specification", chapter 6 "ACPI _DSM Function". According
I'd add a spec version here as well adn maybe a link like it's
in 4/6 (but links are often go stale so it's not must have, just name
and version should be sufficient to find the spec)
> to Laszlo, it's not so easy to implement in OVMF, he suggested to do
> it in qemu instead.
>
> See specification documentation for more details, and next commit for
> memory clear on reset handling.
>
> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
> Tested-by: Stefan Berger <stef...@linux.ibm.com>
With commit amended
Reviewed-by: Igor Mammedov <imamm...@redhat.com>
> ---
> hw/acpi/tpm.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++
> docs/specs/tpm.txt | 2 ++
> 2 files changed, 57 insertions(+)
>
> diff --git a/hw/acpi/tpm.c b/hw/acpi/tpm.c
> index 9f205378f2..b96459e45b 100644
> --- a/hw/acpi/tpm.c
> +++ b/hw/acpi/tpm.c
> @@ -53,6 +53,16 @@ void tpm_build_ppi_acpi(TPMIf *tpm, Aml *dev)
> pprq = aml_name("PPRQ");
> pprm = aml_name("PPRM");
>
> + aml_append(dev,
> + aml_operation_region(
> + "TPP3", AML_SYSTEM_MEMORY,
> + aml_int(TPM_PPI_ADDR_BASE +
> + 0x15a /* movv, docs/specs/tpm.txt */),
> + 0x1));
> + field = aml_field("TPP3", AML_BYTE_ACC, AML_NOLOCK, AML_PRESERVE);
> + aml_append(field, aml_named_field("MOVV", 8));
> + aml_append(dev, field);
> +
> /*
> * DerefOf in Windows is broken with SYSTEM_MEMORY. Use a dynamic
> * operation region inside of a method for getting FUNC[op].
> @@ -399,6 +409,51 @@ void tpm_build_ppi_acpi(TPMIf *tpm, Aml *dev)
> aml_append(ifctx, aml_return(aml_buffer(1, zerobyte)));
> }
> aml_append(method, ifctx);
> +
> + /*
> + * "TCG Platform Reset Attack Mitigation Specification 1.00",
> + * Chapter 6 "ACPI _DSM Function"
> + */
> + ifctx = aml_if(
> + aml_equal(uuid,
> + aml_touuid("376054ED-CC13-4675-901C-4756D7F2D45D")));
> + {
> + /* standard DSM query function */
> + ifctx2 = aml_if(aml_equal(function, zero));
> + {
> + uint8_t byte_list[1] = { 0x03 }; /* functions 1-2 supported
> */
> +
> + aml_append(ifctx2,
> + aml_return(aml_buffer(sizeof(byte_list),
> + byte_list)));
> + }
> + aml_append(ifctx, ifctx2);
> +
> + /*
> + * TCG Platform Reset Attack Mitigation Specification 1.0 Ch.6
> + *
> + * Arg 2 (Integer): Function Index = 1
> + * Arg 3 (Package): Arguments = Package: Type: Integer
> + * Operation Value of the Request
> + * Returns: Type: Integer
> + * 0: Success
> + * 1: General Failure
> + */
> + ifctx2 = aml_if(aml_equal(function, one));
> + {
> + aml_append(ifctx2,
> + aml_store(aml_derefof(aml_index(arguments, zero)),
> + op));
> + {
> + aml_append(ifctx2, aml_store(op, aml_name("MOVV")));
> +
> + /* 0: success */
> + aml_append(ifctx2, aml_return(zero));
> + }
> + }
> + aml_append(ifctx, ifctx2);
> + }
> + aml_append(method, ifctx);
> }
> aml_append(dev, method);
> }
> diff --git a/docs/specs/tpm.txt b/docs/specs/tpm.txt
> index 424d1511fc..5d8c26b1ad 100644
> --- a/docs/specs/tpm.txt
> +++ b/docs/specs/tpm.txt
> @@ -135,6 +135,8 @@ layout:
> +----------+--------+--------+-------------------------------------------+
> | next_step| 0x1 | 0x159 | Operation to execute after reboot by |
> | | | | firmware. Used by firmware. |
> + +----------+--------+--------+-------------------------------------------+
> + | movv | 0x1 | 0x15a | Memory overwrite variable |
> +----------+--------+--------+-------------------------------------------+
>
> The following values are supported for the 'func' field. They correspond
