In general, on an ARM system, mapping normal memory as device memory may have unintended side effects, given that unaligned accesses or loads and stores with special semantics (e.g., load/store exclusive) may fault or may not work as expected.
Under KVM, the situation is even worse, since the host may not expect the guest to perform uncached accesses, and so writes to such an uncached region may get lost completely. Since the only safe mapping type under KVM is EFI_MEMORY_WB, remove all other memory type attributes. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <[email protected]> --- ArmVirtPkg/HighMemDxe/HighMemDxe.c | 3 +-- ArmVirtPkg/Library/ArmVirtMemoryInitPeiLib/ArmVirtMemoryInitPeiLib.c | 3 --- 2 files changed, 1 insertion(+), 5 deletions(-) diff --git a/ArmVirtPkg/HighMemDxe/HighMemDxe.c b/ArmVirtPkg/HighMemDxe/HighMemDxe.c index 7fd7e8e9a539..4d56e6236b54 100644 --- a/ArmVirtPkg/HighMemDxe/HighMemDxe.c +++ b/ArmVirtPkg/HighMemDxe/HighMemDxe.c @@ -78,8 +78,7 @@ InitializeHighMemDxe ( Status = gDS->AddMemorySpace ( EfiGcdMemoryTypeSystemMemory, CurBase, CurSize, - EFI_MEMORY_WB | EFI_MEMORY_WC | - EFI_MEMORY_WT | EFI_MEMORY_UC); + EFI_MEMORY_WB); if (EFI_ERROR (Status)) { DEBUG ((EFI_D_ERROR, diff --git a/ArmVirtPkg/Library/ArmVirtMemoryInitPeiLib/ArmVirtMemoryInitPeiLib.c b/ArmVirtPkg/Library/ArmVirtMemoryInitPeiLib/ArmVirtMemoryInitPeiLib.c index 251e5314e61d..6f3e54b7afcb 100644 --- a/ArmVirtPkg/Library/ArmVirtMemoryInitPeiLib/ArmVirtMemoryInitPeiLib.c +++ b/ArmVirtPkg/Library/ArmVirtMemoryInitPeiLib/ArmVirtMemoryInitPeiLib.c @@ -68,9 +68,6 @@ MemoryPeim ( ResourceAttributes = ( EFI_RESOURCE_ATTRIBUTE_PRESENT | EFI_RESOURCE_ATTRIBUTE_INITIALIZED | - EFI_RESOURCE_ATTRIBUTE_UNCACHEABLE | - EFI_RESOURCE_ATTRIBUTE_WRITE_COMBINEABLE | - EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE | EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE | EFI_RESOURCE_ATTRIBUTE_TESTED ); -- 2.7.4 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
