This patch doesn't change the behavior of AcpiPlatformDxe when
PcdPciDisableBusEnumeration is TRUE -- that is, when the driver runs on
Xen (OvmfPkg and ArmVirtPkg both), or when the driver runs on QEMU as part
of ArmVirtPkg but no PCI host bridge was found by VirtFdtDxe. In these
cases the driver continues to install the ACPI tables immediately.
However, when PcdPciDisableBusEnumeration is FALSE (i.e., when the driver
runs on QEMU as part of OVMF, or as part of ArmVirtPkg and VirtFdtDxe
finds a PCI host bridge), we now delay the ACPI table download from QEMU.
We wait until the Platform BDS tells us that root bridges have been
connected, and PciIo instances are available.
The explanation is in the patch titled
OvmfPkg: introduce gRootBridgesConnectedEventGroupGuid
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
SVN r16411 delayed ACPI table installation until PCI enumeration was
complete, because on QEMU the ACPI-related fw_cfg files should have been
downloaded only after PCI enumeration. Said commit implemented the
dependency by tightening the module's depex.
This patch replaces the EFI_PCI_ENUMERATION_COMPLETE_PROTOCOL depex with a
matching protocol registration callback. The depex was static, and it
could not handle dynamically discovered situations when the dependency
would turn out invalid.
Namely:
- At the moment, the depex in "QemuFwCfgAcpiPlatformDxe.inf" assumes
that "ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc"
lacks PCI support. However, PCI support is about to become run-time
discoverable on that platform. If PCI support is missing, then
ArmVirtualizationPkg will set PcdPciDisableBusEnumeration to TRUE.
Hence, when PcdPciDisableBusEnumeration is TRUE, we invalidate the
dependency by not registering the callback and installing the ACPI
tables right away.
- InitializeXen() in "OvmfPkg/PlatformPei/Xen.c" sets
PcdPciDisableBusEnumeration to TRUE. This causes
PciBusDriverBindingStart() in "MdeModulePkg/Bus/Pci/PciBusDxe/PciBus.c"
to set gFullEnumeration to FALSE, which in turn makes PciEnumerator() in
"MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumerator.c" branch to
PciEnumeratorLight(). The installation of
EFI_PCI_ENUMERATION_COMPLETE_PROTOCOL at the end of PciEnumerator() is
not reached.
Which means that starting with SVN r16411, AcpiPlatformDxe is never
dispatched on Xen.
Hence, when PcdPciDisableBusEnumeration is TRUE, we invalidate the
dependency by not registering the callback and installing the ACPI
tables right away.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
[jordan.l.justen@intel.com: Removed PcdOvmfPciEnabled]
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16887 6f19259b-4bc3-4df7-8a09-765794883524
Currently the entry point functions of both driver builds
(AcpiPlatformDxe.inf and QemuFwCfgAcpiPlatformDxe.inf) directly contain
the logic that is different between the two builds.
Because we're going to restructure the entry point logic soon, we'd have
to duplicate the same new code between both entry point functions.
Push down the logic in which they differ to a new function:
- InstallAcpiTables() [AcpiPlatform.c]
- InstallAcpiTables() [QemuFwCfgAcpiPlatform.c]
and extract a common entry point function:
- AcpiPlatformEntryPoint() [EntryPoint.c]
which we can soon modify without code duplication.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16885 6f19259b-4bc3-4df7-8a09-765794883524
Laszlo Ersek