From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:58323) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ghFIZ-0003EN-4C for qemu-devel@nongnu.org; Wed, 09 Jan 2019 09:57:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ghFIY-0000Gc-0I for qemu-devel@nongnu.org; Wed, 09 Jan 2019 09:57:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:22587) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ghFIX-0008Pb-DZ for qemu-devel@nongnu.org; Wed, 09 Jan 2019 09:57:37 -0500 Date: Wed, 9 Jan 2019 09:57:15 -0500 From: "Michael S. Tsirkin" Message-ID: <20190109095652-mutt-send-email-mst@kernel.org> References: <20190109082902.32271-1-marcandre.lureau@redhat.com> <20190109082902.32271-6-marcandre.lureau@redhat.com> <20190109093518-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v15 5/6] acpi: add ACPI memory clear interface List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?iso-8859-1?Q?Marc-Andr=E9?= Lureau Cc: Eduardo Habkost , Stefan Berger , Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , QEMU , Igor Mammedov , Paolo Bonzini , Richard Henderson , Stefan Berger On Wed, Jan 09, 2019 at 06:55:56PM +0400, Marc-Andr=E9 Lureau wrote: > Hi >=20 > On Wed, Jan 9, 2019 at 6:47 PM Michael S. Tsirkin wrot= e: > > > > On Wed, Jan 09, 2019 at 12:29:01PM +0400, Marc-Andr=E9 Lureau wrote: > > > The interface is described in the "TCG Platform Reset Attack > > > Mitigation Specification", chapter 6 "ACPI _DSM Function". Accordin= g > > > to Laszlo, it's not so easy to implement in OVMF, he suggested to d= o > > > it in qemu instead. > > > > > > See specification documentation for more details, and next commit f= or > > > memory clear on reset handling. > > > > > > Signed-off-by: Marc-Andr=E9 Lureau > > > --- > > > hw/acpi/tpm.c | 48 ++++++++++++++++++++++++++++++++++++++++++= ++++ > > > docs/specs/tpm.txt | 2 ++ > > > 2 files changed, 50 insertions(+) > > > > > > diff --git a/hw/acpi/tpm.c b/hw/acpi/tpm.c > > > index fee9490306..61da1de97b 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 =3D aml_name("PPRQ"); > > > pprm =3D 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 =3D aml_field("TPP3", AML_BYTE_ACC, AML_NOLOCK, AML_PRES= ERVE); > > > + aml_append(field, aml_named_field("MOVV", 8)); > > > + aml_append(dev, field); > > > + > > > /* > > > * DerefOf in Windows is broken with SYSTEM_MEMORY. Use a dyn= amic > > > * operation region inside of a method for getting FUNC[op]. > > > @@ -395,6 +405,44 @@ void tpm_build_ppi_acpi(TPMIf *tpm, Aml *dev) > > > aml_append(ifctx, aml_return(aml_buffer(1, zerobyte)))= ; > > > } > > > aml_append(method, ifctx); > > > + > > > + ifctx =3D aml_if( > > > + aml_equal(uuid, > > > + aml_touuid("376054ED-CC13-4675-901C-4756D7F2= D45D"))); > > > + { > > > + /* standard DSM query function */ > > > > refer to spec chapter here? >=20 > Yes, we could add a code comment such as: > /* "TCG Platform Reset Attack Mitigation Specification", chapter 6 > "ACPI _DSM Function" */ You want to include the version as well. >=20 > > > > > + ifctx2 =3D aml_if(aml_equal(function, zero)); > > > + { > > > + uint8_t byte_list[1] =3D { 0x03 }; > > > > and explain 3 above? >=20 > /* functions 1-2 are supported */ >=20 > > > > > + aml_append(ifctx2, aml_return(aml_buffer(1 > > > > 1 -> sizeof(byte_list)? >=20 > ok >=20 > > > > > + , byte_list))); > > > + } > > > + aml_append(ifctx, ifctx2); > > > + > > > + /* > > > + * TCG Platform Reset Attack Mitigation Specification = 1.0 Ch.6 > > > + * > > > + * Arg 2 (Integer): Function Index =3D 1 > > > + * Arg 3 (Package): Arguments =3D Package: Type: Integ= er > > > + * Operation Value of the Request > > > + * Returns: Type: Integer > > > + * 0: Success > > > + * 1: General Failure > > > + */ > > > + ifctx2 =3D aml_if(aml_equal(function, one)); > > > + { > > > + aml_append(ifctx2, > > > + aml_store(aml_derefof(aml_index(argumen= ts, zero)), > > > + op)); > > > + { > > > + aml_append(ifctx2, aml_store(op, aml_name("MOV= V"))); > > > + > > > + /* 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 c= orrespond > > > -- > > > 2.20.1.2.gb21ebb671b > > >=20 >=20 > --=20 > Marc-Andr=E9 Lureau