diff options
Diffstat (limited to 'ArmPlatformPkg')
4 files changed, 50 insertions, 2 deletions
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec b/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec index 99411548af..d53dab9f65 100644 --- a/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec +++ b/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec @@ -56,3 +56,28 @@ gArmVirtualizationTokenSpaceGuid.PcdFwCfgSelectorAddress|0x0|UINT64|0x00000004
gArmVirtualizationTokenSpaceGuid.PcdFwCfgDataAddress|0x0|UINT64|0x00000005
+
+[PcdsFeatureFlag]
+ #
+ # "Map PCI MMIO as Cached"
+ #
+ # Due to the way Stage1 and Stage2 mappings are combined on Aarch64, and
+ # because KVM -- for the time being -- does not try to interfere with the
+ # Stage1 mappings, we must not set EFI_MEMORY_UC for emulated PCI MMIO
+ # regions.
+ #
+ # EFI_MEMORY_UC is mapped to Device-nGnRnE, and that Stage1 attribute would
+ # direct guest writes to host DRAM immediately, bypassing the cache
+ # regardless of Stage2 attributes. However, QEMU's reads of the same range
+ # can easily be served from the (stale) CPU cache.
+ #
+ # Setting this PCD to TRUE will use EFI_MEMORY_WB for mapping PCI MMIO
+ # regions, which ensures that guest writes to such regions go through the CPU
+ # cache. Strictly speaking this is wrong, but it is needed as a temporary
+ # workaround for emulated PCI devices. Setting the PCD to FALSE results in
+ # the theoretically correct EFI_MEMORY_UC mapping, and should be the long
+ # term choice, especially with assigned devices.
+ #
+ # The default is to turn off the kludge; DSC's can selectively enable it.
+ #
+ gArmVirtualizationTokenSpaceGuid.PcdKludgeMapPciMmioAsCached|FALSE|BOOLEAN|0x00000006
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc b/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc index 19776100a5..66fe9798c6 100644 --- a/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc +++ b/ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationQemu.dsc @@ -86,6 +86,9 @@ # It could be set FALSE to save size.
gEfiMdeModulePkgTokenSpaceGuid.PcdConOutGopSupport|FALSE
+ # Activate KVM workaround for now.
+ gArmVirtualizationTokenSpaceGuid.PcdKludgeMapPciMmioAsCached|TRUE
+
[PcdsFixedAtBuild.common]
gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel|0x8000004F
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c index 452465afa8..17d4db85be 100644 --- a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c +++ b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridge.c @@ -97,6 +97,7 @@ InitializePciHostBridge ( IN EFI_SYSTEM_TABLE *SystemTable
)
{
+ UINT64 MmioAttributes;
EFI_STATUS Status;
UINTN Loop1;
UINTN Loop2;
@@ -133,17 +134,31 @@ InitializePciHostBridge ( );
ASSERT_EFI_ERROR (Status);
+ MmioAttributes = FeaturePcdGet (PcdKludgeMapPciMmioAsCached) ?
+ EFI_MEMORY_WB : EFI_MEMORY_UC;
+
Status = gDS->AddMemorySpace (
EfiGcdMemoryTypeMemoryMappedIo,
PcdGet32 (PcdPciMmio32Base),
PcdGet32 (PcdPciMmio32Size),
- EFI_MEMORY_UC
+ MmioAttributes
);
if (EFI_ERROR (Status)) {
DEBUG ((EFI_D_ERROR, "%a: AddMemorySpace: %r\n", __FUNCTION__, Status));
return Status;
}
+ Status = gDS->SetMemorySpaceAttributes (
+ PcdGet32 (PcdPciMmio32Base),
+ PcdGet32 (PcdPciMmio32Size),
+ MmioAttributes
+ );
+ if (EFI_ERROR (Status)) {
+ DEBUG ((EFI_D_ERROR, "%a: SetMemorySpaceAttributes: %r\n", __FUNCTION__,
+ Status));
+ return Status;
+ }
+
//
// Create Host Bridge Device Handle
//
diff --git a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridgeDxe.inf b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridgeDxe.inf index 5497fa61d2..ecea088272 100644 --- a/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridgeDxe.inf +++ b/ArmPlatformPkg/ArmVirtualizationPkg/PciHostBridgeDxe/PciHostBridgeDxe.inf @@ -24,6 +24,7 @@ [Packages]
MdePkg/MdePkg.dec
ArmPlatformPkg/ArmPlatformPkg.dec
+ ArmPlatformPkg/ArmVirtualizationPkg/ArmVirtualizationPkg.dec
[LibraryClasses]
UefiDriverEntryPoint
@@ -60,5 +61,9 @@ gArmPlatformTokenSpaceGuid.PcdPciMmio32Size
gEfiMdePkgTokenSpaceGuid.PcdPciExpressBaseAddress
+[FeaturePcd]
+ gArmVirtualizationTokenSpaceGuid.PcdKludgeMapPciMmioAsCached
+
[depex]
- gEfiMetronomeArchProtocolGuid
+ gEfiMetronomeArchProtocolGuid AND
+ gEfiCpuArchProtocolGuid
|