[edk2-devel] [PATCH v2] OvmfPkg: use DxeTpmMeasurementLib if and only if TPM2_ENABLE
Laszlo Ersek
lersek at redhat.com
Thu Jul 4 13:53:13 UTC 2019
On 07/04/19 06:07, Gary Lin wrote:
> (a) OvmfPkg first had to resolve the TpmMeasurementLib class -- for
> SECURE_BOOT_ENABLE only -- when the DxeImageVerificationLib instance
> became dependent on TpmMeasurementLib. For details, refer to commit
> 0d28d286bf4d ("OvmfPkg: resolve TpmMeasurementLib dependency
> introduced in r14687", 2013-09-21).
>
> (b) At the time, only one instance of TpmMeasurementLib existed, namely
> DxeTpmMeasurementLib. This lib instance didn't do anything -- like it
> was desirable for OVMF --, because OVMF didn't include any Tcg / TrEE
> protocol implementations.
>
> (c) In commit 308521b13354 ("MdeModulePkg: Move TpmMeasurementLib
> LibraryClass from SecurityPkg", 2015-07-01), TpmMeasurementLibNull was
> introduced.
>
> (d) In commit 285542ebbb03 ("OvmfPkg: Link AuthVariableLib for following
> merged variable driver deploy", 2015-07-01), a TpmMeasurementLib
> resolution became necessary regardless of SECURE_BOOT_ENABLE. And so
> TpmMeasurementLib was resolved to TpmMeasurementLibNull in OVMF, but
> only in the non-SECURE_BOOT_ENABLE case. This step -- possibly, the
> larger series containing commit 285542ebbb03 -- missed an opportunity
> for simplification: given (b), the DxeTpmMeasurementLib instance
> should have been simply replaced with the TpmMeasurementLibNull
> instance, regardless of SECURE_BOOT_ENABLE.
>
> (e) In commit 1abfa4ce4835 ("Add TPM2 support defined in trusted computing
> group.", 2015-08-13), the TrEE dependency was replaced with a Tcg2
> dependency in DxeTpmMeasurementLib.
>
> (f) Starting with commit 0c0a50d6b3ff ("OvmfPkg: include Tcg2Dxe module",
> 2018-03-09), OVMF would include a Tcg2 protocol implementation,
> thereby satisfying DxeTpmMeasurementLib's dependency. With
> TPM2_ENABLE, it would actually make sense to consume
> DxeTpmMeasurementLib -- however, DxeTpmMeasurementLib would never be
> used without SECURE_BOOT_ENABLE.
>
> Therefore, we have the following four scenarios:
>
> - TPM2_ENABLE + SECURE_BOOT_ENABLE: works as expected.
>
> - Neither enabled: works as expected.
>
> - Only TPM2_ENABLE: this build is currently incorrect, because
> Variable/RuntimeDxe consumes TpmMeasurementLib directly, but
> TpmMeasureAndLogData() will never reach the TPM because we link
> TpmMeasurementLibNull into the variable driver. This is a problem from
> the larger series containing (f).
>
> - Only SECURE_BOOT_ENABLE: this build works as expected, but it is
> wasteful -- given that the protocol database will never contain Tcg2
> without TPM2_ENABLE, we should simply use TpmMeasurementLibNull. This is
> a problem from (d).
>
> Resolving TpmMeasurementLib to DxeTpmMeasurementLib as a function of
> *only* TPM2_ENABLE, we can fix / optimize the last two cases.
>
> v2:
> - Amend the title and description suggested by Laszlo
> - Move TpmMeasurementLib to the existed TPM2_ENABLE block
>
> Cc: Jordan Justen <jordan.l.justen at intel.com>
> Cc: Laszlo Ersek <lersek at redhat.com>
> Cc: Marc-André Lureau <marcandre.lureau at redhat.com>
> Cc: Stefan Berger <stefanb at linux.ibm.com>
> Signed-off-by: Gary Lin <glin at suse.com>
> ---
> OvmfPkg/OvmfPkgIa32.dsc | 4 ++--
> OvmfPkg/OvmfPkgIa32X64.dsc | 4 ++--
> OvmfPkg/OvmfPkgX64.dsc | 4 ++--
> 3 files changed, 6 insertions(+), 6 deletions(-)
Reviewed-by: Laszlo Ersek <lersek at redhat.com>
Pushed as commit 1ec05b81e59f.
Thanks!
Laszlo
> diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
> index 87716123997a..5bbf87540ab9 100644
> --- a/OvmfPkg/OvmfPkgIa32.dsc
> +++ b/OvmfPkg/OvmfPkgIa32.dsc
> @@ -178,10 +178,8 @@ [LibraryClasses]
>
> !if $(SECURE_BOOT_ENABLE) == TRUE
> PlatformSecureLib|OvmfPkg/Library/PlatformSecureLib/PlatformSecureLib.inf
> - TpmMeasurementLib|SecurityPkg/Library/DxeTpmMeasurementLib/DxeTpmMeasurementLib.inf
> AuthVariableLib|SecurityPkg/Library/AuthVariableLib/AuthVariableLib.inf
> !else
> - TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
> AuthVariableLib|MdeModulePkg/Library/AuthVariableLibNull/AuthVariableLibNull.inf
> !endif
> VarCheckLib|MdeModulePkg/Library/VarCheckLib/VarCheckLib.inf
> @@ -207,8 +205,10 @@ [LibraryClasses]
> Tpm2CommandLib|SecurityPkg/Library/Tpm2CommandLib/Tpm2CommandLib.inf
> Tcg2PhysicalPresenceLib|OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.inf
> Tcg2PpVendorLib|SecurityPkg/Library/Tcg2PpVendorLibNull/Tcg2PpVendorLibNull.inf
> + TpmMeasurementLib|SecurityPkg/Library/DxeTpmMeasurementLib/DxeTpmMeasurementLib.inf
> !else
> Tcg2PhysicalPresenceLib|OvmfPkg/Library/Tcg2PhysicalPresenceLibNull/DxeTcg2PhysicalPresenceLib.inf
> + TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
> !endif
>
> [LibraryClasses.common]
> diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
> index ad20531ceb8b..5015e92b6eea 100644
> --- a/OvmfPkg/OvmfPkgIa32X64.dsc
> +++ b/OvmfPkg/OvmfPkgIa32X64.dsc
> @@ -183,10 +183,8 @@ [LibraryClasses]
>
> !if $(SECURE_BOOT_ENABLE) == TRUE
> PlatformSecureLib|OvmfPkg/Library/PlatformSecureLib/PlatformSecureLib.inf
> - TpmMeasurementLib|SecurityPkg/Library/DxeTpmMeasurementLib/DxeTpmMeasurementLib.inf
> AuthVariableLib|SecurityPkg/Library/AuthVariableLib/AuthVariableLib.inf
> !else
> - TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
> AuthVariableLib|MdeModulePkg/Library/AuthVariableLibNull/AuthVariableLibNull.inf
> !endif
> VarCheckLib|MdeModulePkg/Library/VarCheckLib/VarCheckLib.inf
> @@ -212,8 +210,10 @@ [LibraryClasses]
> Tpm2CommandLib|SecurityPkg/Library/Tpm2CommandLib/Tpm2CommandLib.inf
> Tcg2PhysicalPresenceLib|OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.inf
> Tcg2PpVendorLib|SecurityPkg/Library/Tcg2PpVendorLibNull/Tcg2PpVendorLibNull.inf
> + TpmMeasurementLib|SecurityPkg/Library/DxeTpmMeasurementLib/DxeTpmMeasurementLib.inf
> !else
> Tcg2PhysicalPresenceLib|OvmfPkg/Library/Tcg2PhysicalPresenceLibNull/DxeTcg2PhysicalPresenceLib.inf
> + TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
> !endif
>
> [LibraryClasses.common]
> diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
> index 0542ac2235b4..dda8dac18441 100644
> --- a/OvmfPkg/OvmfPkgX64.dsc
> +++ b/OvmfPkg/OvmfPkgX64.dsc
> @@ -183,10 +183,8 @@ [LibraryClasses]
>
> !if $(SECURE_BOOT_ENABLE) == TRUE
> PlatformSecureLib|OvmfPkg/Library/PlatformSecureLib/PlatformSecureLib.inf
> - TpmMeasurementLib|SecurityPkg/Library/DxeTpmMeasurementLib/DxeTpmMeasurementLib.inf
> AuthVariableLib|SecurityPkg/Library/AuthVariableLib/AuthVariableLib.inf
> !else
> - TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
> AuthVariableLib|MdeModulePkg/Library/AuthVariableLibNull/AuthVariableLibNull.inf
> !endif
> VarCheckLib|MdeModulePkg/Library/VarCheckLib/VarCheckLib.inf
> @@ -212,8 +210,10 @@ [LibraryClasses]
> Tpm2CommandLib|SecurityPkg/Library/Tpm2CommandLib/Tpm2CommandLib.inf
> Tcg2PhysicalPresenceLib|OvmfPkg/Library/Tcg2PhysicalPresenceLibQemu/DxeTcg2PhysicalPresenceLib.inf
> Tcg2PpVendorLib|SecurityPkg/Library/Tcg2PpVendorLibNull/Tcg2PpVendorLibNull.inf
> + TpmMeasurementLib|SecurityPkg/Library/DxeTpmMeasurementLib/DxeTpmMeasurementLib.inf
> !else
> Tcg2PhysicalPresenceLib|OvmfPkg/Library/Tcg2PhysicalPresenceLibNull/DxeTcg2PhysicalPresenceLib.inf
> + TpmMeasurementLib|MdeModulePkg/Library/TpmMeasurementLibNull/TpmMeasurementLibNull.inf
> !endif
>
> [LibraryClasses.common]
>
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#43274): https://edk2.groups.io/g/devel/message/43274
Mute This Topic: https://groups.io/mt/32305122/1813853
Group Owner: devel+owner at edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [edk2-devel-archive at redhat.com]
-=-=-=-=-=-=-=-=-=-=-=-
More information about the edk2-devel-archive
mailing list