Operating Systems that get hibernated expect all non-boot-time allocations
to be identical before and after hibernation.
In edk2, we create pools and allocate pages starting from the highest
allowed address for the allocation, usually 0xFFFFFFFF. Typically, that
means we allocate a few pages of boot time data, then a few pages of
runtime data, then another few pages of boot time data and again runtime
data. Every allocation has direct impact on the following allocations.
The problem with this scheme is that small code changes in boot time code
already can have significant impact on runtime allocations, which then
break hibernation.
This patch adds a mechanism to override the MaxAddress for runtime
allocations with a target defined Pcd value. With this feature enabled,
we can have different allocation ranges for runtime and boot time
allocations.
This allows us to determine at boot time whether to load an old,
hibernation compatible runtime allocation path or a new, hibernation
unsafe runtime allocation. All within the same edk2 target binary.
It also allows us to modify boot time behavior, such as modifying
buffer allocation mechanisms without compromising on hibernation safety.
Signed-off-by: Alexander Graf <g...@amazon.com>
---
MdeModulePkg/Core/Dxe/DxeMain.inf | 4 +++
MdeModulePkg/Core/Dxe/Mem/Page.c | 70 +++++++++++++++++++++++++++++++++++++++
MdeModulePkg/MdeModulePkg.dec | 16 +++++++++
MdeModulePkg/MdeModulePkg.uni | 12 +++++++
4 files changed, 102 insertions(+)
diff --git a/MdeModulePkg/Core/Dxe/DxeMain.inf
b/MdeModulePkg/Core/Dxe/DxeMain.inf
index e4bca89577..0696246970 100644
--- a/MdeModulePkg/Core/Dxe/DxeMain.inf
+++ b/MdeModulePkg/Core/Dxe/DxeMain.inf
@@ -186,6 +186,10 @@
gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask ##
CONSUMES
gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard ##
CONSUMES
gEfiMdeModulePkgTokenSpaceGuid.PcdFwVolDxeMaxEncapsulationDepth ##
CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxACPIReclaimMemory ##
CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxACPIMemoryNVS ##
CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxEfiRuntimeServicesCode ##
CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxEfiRuntimeServicesData ##
CONSUMES
# [Hob]
# RESOURCE_DESCRIPTOR ## CONSUMES
diff --git a/MdeModulePkg/Core/Dxe/Mem/Page.c b/MdeModulePkg/Core/Dxe/Mem/Page.c
index 731bf08bc9..91599adccb 100644
--- a/MdeModulePkg/Core/Dxe/Mem/Page.c
+++ b/MdeModulePkg/Core/Dxe/Mem/Page.c
@@ -1007,6 +1007,74 @@ CoreUpdateMemoryAttributes (
CoreReleaseMemoryLock ();
}
+UINT64
+EnforceMaxAddress (
+ IN UINT64 MaxAddress,
+ IN EFI_MEMORY_TYPE NewType,
+ IN UINT64 NumberOfPages
+ )
+{
+ UINT64 NumberOfBytes = LShiftU64 (NumberOfPages, EFI_PAGE_SHIFT);
+ UINT64 LowestPossible = MaxAddress;
+ UINT64 ForceMaxAddress;
+ LIST_ENTRY *Link;
+ MEMORY_MAP *Entry;
+
+ switch (NewType) {
+ case EfiACPIReclaimMemory:
+ ForceMaxAddress = PcdGet64(PcdEnforceMaxACPIReclaimMemory);
+ break;
+ case EfiACPIMemoryNVS:
+ ForceMaxAddress = PcdGet64(PcdEnforceMaxACPIMemoryNVS);
+ break;
+ case EfiRuntimeServicesCode:
+ ForceMaxAddress = PcdGet64(PcdEnforceMaxEfiRuntimeServicesCode);
+ break;
+ case EfiRuntimeServicesData:
+ ForceMaxAddress = PcdGet64(PcdEnforceMaxEfiRuntimeServicesData);
+ break;
+ default:
+ ForceMaxAddress = MaxAddress;
+ break;
+ }
+
+ //
+ // The currently requested address already fits our forced max constraint?
+ // Great, let's use that then.
+ //
+ if (ForceMaxAddress >= MaxAddress) {
+ return MaxAddress;
+ }
+
+ //
+ // Check if the allocation would fit. If not, don't force it.
+ //
+ for (Link = gMemoryMap.ForwardLink; Link != &gMemoryMap; Link =
Link->ForwardLink) {
+ Entry = CR (Link, MEMORY_MAP, Link, MEMORY_MAP_SIGNATURE);
+
+ //
+ // If it's not a free entry, don't bother with it
+ //
+ if (Entry->Type != EfiConventionalMemory) {
+ continue;
+ }
+
+ if ((Entry->Start < LowestPossible) &&
+ ((Entry->End - Entry->Start) >= NumberOfBytes)) {
+ LowestPossible = Entry->End;
+ }
+ }
+ DEBUG ((DEBUG_ERROR | DEBUG_PAGE, "Force=%lx Lowest=%lx Max=%lx\n",
ForceMaxAddress, LowestPossible, MaxAddress));
+
+ //
+ // We don't have free RAM available in the desired target area? Bail out!
+ //
+ if (ForceMaxAddress < LowestPossible) {
+ return MaxAddress;
+ }
+
+ return ForceMaxAddress;
+}
/**
Internal function. Finds a consecutive free page range below
@@ -1041,6 +1109,8 @@ CoreFindFreePagesI (
LIST_ENTRY *Link;
MEMORY_MAP *Entry;
+ MaxAddress = EnforceMaxAddress(MaxAddress, NewType, NumberOfPages);
+
if ((MaxAddress < EFI_PAGE_MASK) ||(NumberOfPages == 0)) {
return 0;
}
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 1483955110..cbad48af5e 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -1535,6 +1535,22 @@
# @Prompt Maximum permitted FwVol section nesting depth (exclusive).
gEfiMdeModulePkgTokenSpaceGuid.PcdFwVolDxeMaxEncapsulationDepth|0x10|UINT32|0x00000030
+ ## Maximum address that a dynamic EfiACPIReclaimMemory allocation can be
requested at
+ # @Prompt Maximum address for EfiACPIReclaimMemory allocations
+
gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxACPIReclaimMemory|0xFFFFFFFFFFFFFFFF|UINT64|0x30001016
+
+ ## Maximum address that a dynamic EfiACPIMemoryNVS allocation can be
requested at
+ # @Prompt Maximum address for EfiACPIMemoryNVS allocations
+
gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxACPIMemoryNVS|0xFFFFFFFFFFFFFFFF|UINT64|0x30001017
+
+ ## Maximum address that a dynamic EfiRuntimeServicesCode allocation can be
requested at
+ # @Prompt Maximum address for EfiRuntimeServicesCode allocations
+
gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxEfiRuntimeServicesCode|0xFFFFFFFFFFFFFFFF|UINT64|0x30001018
+
+ ## Maximum address that a dynamic EfiRuntimeServicesData allocation can be
requested at
+ # @Prompt Maximum address for EfiRuntimeServicesData allocations
+
gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxEfiRuntimeServicesData|0xFFFFFFFFFFFFFFFF|UINT64|0x30001019
+
[PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]
## This PCD defines the Console output row. The default value is 25
according to UEFI spec.
# This PCD could be set to 0 then console output would be at max column and
max row.
diff --git a/MdeModulePkg/MdeModulePkg.uni b/MdeModulePkg/MdeModulePkg.uni
index ef9f4d97b9..0dc5c1960b 100644
--- a/MdeModulePkg/MdeModulePkg.uni
+++ b/MdeModulePkg/MdeModulePkg.uni
@@ -1330,3 +1330,15 @@
#string STR_gEfiMdeModulePkgTokenSpaceGuid_PcdPcieResizableBarSupport_HELP
#language en-US "Indicates if the PCIe Resizable BAR Capability
Supported.<BR><BR>\n"
"TRUE - PCIe Resizable BAR Capability is supported.<BR>\n"
"FALSE - PCIe Resizable BAR Capability is not supported.<BR>"
+
+#string
STR_gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxACPIReclaimMemory_PROMPT
#language en-US "Maximum address for EfiACPIReclaimMemory allocations"
+#string STR_gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxACPIReclaimMemory_HELP
#language en-US "Maximum address that a dynamic EfiACPIReclaimMemory allocation
can be requested at"
+
+#string STR_gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxACPIMemoryNVS_PROMPT
#language en-US "Maximum address for EfiACPIMemoryNVS allocations"
+#string STR_gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxACPIMemoryNVS_HELP
#language en-US "Maximum address that a dynamic EfiACPIMemoryNVS allocation can
be requested at"
+
+#string
STR_gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxEfiRuntimeServicesCode_PROMPT
#language en-US "Maximum address for EfiRuntimeServicesCode allocations"
+#string
STR_gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxEfiRuntimeServicesCode_HELP
#language en-US "Maximum address that a dynamic EfiRuntimeServicesCode
allocation can be requested at"
+
+#string
STR_gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxEfiRuntimeServicesData_PROMPT
#language en-US "Maximum address for EfiRuntimeServicesData allocations"
+#string
STR_gEfiMdeModulePkgTokenSpaceGuid.PcdEnforceMaxEfiRuntimeServicesData_HELP
#language en-US "Maximum address that a dynamic EfiRuntimeServicesData
allocation can be requested at"
--
2.16.4
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#71792): https://edk2.groups.io/g/devel/message/71792
Mute This Topic: https://groups.io/mt/80739508/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
