Reviewed-by: jiewen....@intel.com > -----Original Message----- > From: Laszlo Ersek [mailto:ler...@redhat.com] > Sent: Thursday, March 9, 2017 3:59 AM > To: edk2-devel-01 <edk2-de...@ml01.01.org> > Cc: Al Stone <a...@redhat.com>; Ard Biesheuvel <ard.biesheu...@linaro.org>; > Tian, Feng <feng.t...@intel.com>; Igor Mammedov <imamm...@redhat.com>; > Yao, Jiewen <jiewen....@intel.com>; Leo Duran <leo.du...@amd.com>; > Michael Tsirkin <mtsir...@redhat.com>; Phil Dennis-Jordan > <p...@philjordan.eu>; Zeng, Star <star.z...@intel.com> > Subject: [PATCH v2 2/2] MdeModulePkg/AcpiTableDxe: improve > FADT.{DSDT,X_DSDT} mutual exclusion > > The ACPI specification, up to and including revision 5.1 Errata A, allows > the DSDT and X_DSDT fields to be both set in the FADT. (Obviously, this > only makes sense if the DSDT address is representable in 4 bytes.) > > Starting with 5.1 Errata B, specifically for Mantis 1393 > <https://mantis.uefi.org/mantis/view.php?id=1393>, the spec requires at > most one of DSDT and X_DSDT to be set to a nonzero value. > > MdeModulePkg/AcpiTableDxe handles this mutual exclusion somewhat > inconsistently. > > - If the caller of EFI_ACPI_TABLE_PROTOCOL.InstallAcpiTable() installs the > tables in "DSDT, FADT" order, then we enforce the exclusion between the > DSDT and X_DSDT fields: > > DSDT under 4GB FADT.DSDT FADT.X_DSDT [VARIANT B] > -------------- --------- ----------- > yes set clear > no clear set > > This behavior conforms to 5.1 Errata B. (And it's not required by > earlier versions of the spec.) > > - If the caller passes in the tables in "FADT, DSDT" relative order, then > we do not enforce the exclusion: > > DSDT under 4GB FADT.DSDT FADT.X_DSDT [VARIANT A] > -------------- --------- ----------- > yes set set > no clear set > > This satisfies 5.1 Errata A and earlier, but breaks 5.1 Errata B and > later. > > Unify the handling of both relative orders. In particular, check the major > and minor version numbers in the FADT. If the FADT version is strictly > before 5.1, then implement [VARIANT A]. If the FADT version is equal to or > larger than 5.1, then implement [VARIANT B]. > > We make three observations: > > - We can't check the FADT table version precisely against "5.1 Errata B"; > erratum levels are not captured in the table. We err in the safe > direction, namely we enforce the exclusion for "5.1" and "5.1 Errata A". > > - The same applies to "6.0" versus "6.0 Errata A". Because we cannot > distinguish these two, we consider "6.0" to be "equal to or larger than > 5.1", and apply [VARIANT B], enforcing the exclusion. > > - While a blanket [VARIANT B] would be simpler, there is a significant > benefit to [VARIANT A], under the spec versions that permit it: > compatibility with a wider range of OSPMs (typically, older ones). > > For example, Igor reported about a "DELL R430 system with rev4 FADT > where DSDT and X_DSDT are pointing to the same address". Michael also > reported about several systems that exhibit the same. > > Regression tested with the following KVM guests (QEMU built at > ata0def594286d, "Merge remote-tracking branch > 'remotes/bonzini/tags/for-upstream' into staging", 2017-01-30): > > - OVMF: boot and S3 suspend/resume > - Ia32, Q35, SMM > - Fedlet 20141209 > - Ia32X64, Q35, SMM > - Fedora 22 > - Windows 7 > - Windows 8.1 > - Windows 10 > - Windows Server 2008 R2 > - Windows Server 2012 R2 > - Windows Server 2016 Tech Preview 4 > - X64, I440FX, no SMM > - Fedora 24 > - RHEL-6.7 > - RHEL-7.2-ish > - ArmVirtQemu: boot test with virtio-gpu > - AARCH64 > - Fedora 24 > - RHELSA-7.3 > - openSUSE Tumbleweed (4.8.4-based) > > This change is connected to ASWG ticket > <https://mantis.uefi.org/mantis/view.php?id=1757>, which is now > closed/fixed. > > Cc: Al Stone <a...@redhat.com> > Cc: Ard Biesheuvel <ard.biesheu...@linaro.org> > Cc: Feng Tian <feng.t...@intel.com> > Cc: Igor Mammedov <imamm...@redhat.com> > Cc: Jiewen Yao <jiewen....@intel.com> > Cc: Leo Duran <leo.du...@amd.com> > Cc: Michael Tsirkin <mtsir...@redhat.com> > Cc: Phil Dennis-Jordan <p...@philjordan.eu> > Cc: Star Zeng <star.z...@intel.com> > Reported-by: Phil Dennis-Jordan <p...@philjordan.eu> > Suggested-by: Igor Mammedov <imamm...@redhat.com> > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Laszlo Ersek <ler...@redhat.com> > Reviewed-by: Phil Dennis-Jordan <p...@philjordan.eu> > --- > > Notes: > v2: > - simplify logic in RequireDsdtXDsdtExclusion() [Jiewen] > - pick up Phil's R-b nonetheless (the above change is a minimal > reformulation of code, with no behavioral difference) > - add reference to Mantis#1757 to the commit message > > v1: > NOTE for people on the CC list: > > If you are not presently subscribed to edk2-devel and wish to comment on > this patch publicly, you need to subscribe first, and wait for the > subscription request to *complete* (see your inbox), *before* sending > your followup. This is not ideal, but edk2-devel requires subscription > before reflecting messages from someone. > > Subscribe at <https://lists.01.org/mailman/listinfo/edk2-devel>. Thanks. > > MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c | 62 > +++++++++++++++++++- > 1 file changed, 59 insertions(+), 3 deletions(-) > > diff --git a/MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c > b/MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c > index 7795ff7269ca..4bb848df5203 100644 > --- a/MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c > +++ b/MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c > @@ -430,6 +430,51 @@ ReallocateAcpiTableBuffer ( > mEfiAcpiMaxNumTables = NewMaxTableNumber; > return EFI_SUCCESS; > } > + > +/** > + Determine whether the FADT table passed in as parameter requires mutual > + exclusion between the DSDT and X_DSDT fields. (That is, whether there > exists > + an explicit requirement that at most one of those fields is permitted to be > + nonzero.) > + > + @param[in] Fadt The EFI_ACPI_3_0_FIXED_ACPI_DESCRIPTION_TABLE > object to > + check. > + > + @retval TRUE Fadt requires mutual exclusion between DSDT and > X_DSDT. > + @retval FALSE Otherwise. > +**/ > +BOOLEAN > +RequireDsdtXDsdtExclusion ( > + IN EFI_ACPI_3_0_FIXED_ACPI_DESCRIPTION_TABLE *Fadt > + ) > +{ > + // > + // Mantis ticket #1393 was addressed in ACPI 5.1 Errata B. Unfortunately, > we > + // can't tell apart 5.1 Errata A and 5.1 Errata B just from looking at the > + // FADT table. Therefore let's require exclusion for table versions >= 5.1. > + // > + // While this needlessly covers 5.1 and 5.1A too, it is safer to require > + // DSDT<->X_DSDT exclusion for lax (5.1, 5.1A) versions of the spec than to > + // permit DSDT<->X_DSDT duplication for strict (5.1B) versions of the spec. > + // > + // The same applies to 6.0 vs. 6.0A. While 6.0 does not require the > + // exclusion, 6.0A and 6.1 do. Since we cannot distinguish 6.0 from 6.0A > + // based on just the FADT, we lump 6.0 in with the rest of >= 5.1. > + // > + if ((Fadt->Header.Revision < 5) || > + ((Fadt->Header.Revision == 5) && > + (((EFI_ACPI_5_1_FIXED_ACPI_DESCRIPTION_TABLE > *)Fadt)->MinorVersion == 0))) { > + // > + // version <= 5.0 > + // > + return FALSE; > + } > + // > + // version >= 5.1 > + // > + return TRUE; > +} > + > /** > This function adds an ACPI table to the table list. It will detect FACS > and > allocate the correct type of memory and properly align the table. > @@ -647,12 +692,16 @@ AddTableToList ( > } > if ((UINT64)(UINTN)AcpiTableInstance->Dsdt3 < BASE_4GB) { > AcpiTableInstance->Fadt3->Dsdt = (UINT32) (UINTN) > AcpiTableInstance->Dsdt3; > - ZeroMem (&AcpiTableInstance->Fadt3->XDsdt, sizeof (UINT64)); > + if (RequireDsdtXDsdtExclusion (AcpiTableInstance->Fadt3)) { > + Buffer64 = 0; > + } else { > + Buffer64 = AcpiTableInstance->Fadt3->Dsdt; > + } > } else { > AcpiTableInstance->Fadt3->Dsdt = 0; > Buffer64 = (UINT64) (UINTN) AcpiTableInstance->Dsdt3; > - CopyMem (&AcpiTableInstance->Fadt3->XDsdt, &Buffer64, sizeof > (UINT64)); > } > + CopyMem (&AcpiTableInstance->Fadt3->XDsdt, &Buffer64, sizeof > (UINT64)); > > // > // RSDP OEM information is updated to match the FADT OEM information > @@ -847,8 +896,15 @@ AddTableToList ( > if (AcpiTableInstance->Fadt3 != NULL) { > if ((UINT64)(UINTN)AcpiTableInstance->Dsdt3 < BASE_4GB) { > AcpiTableInstance->Fadt3->Dsdt = (UINT32) (UINTN) > AcpiTableInstance->Dsdt3; > + if (RequireDsdtXDsdtExclusion (AcpiTableInstance->Fadt3)) { > + Buffer64 = 0; > + } else { > + Buffer64 = AcpiTableInstance->Fadt3->Dsdt; > + } > + } else { > + AcpiTableInstance->Fadt3->Dsdt = 0; > + Buffer64 = (UINT64) (UINTN) AcpiTableInstance->Dsdt3; > } > - Buffer64 = (UINT64) (UINTN) AcpiTableInstance->Dsdt3; > CopyMem (&AcpiTableInstance->Fadt3->XDsdt, &Buffer64, sizeof > (UINT64)); > > // > -- > 2.9.3
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