On 09/08/16 09:50, Ard Biesheuvel wrote: > 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 > ); >
Reviewed-by: Laszlo Ersek <[email protected]> Did you encounter any specific problem with these? Thanks Laszlo _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
