The flash memory range is an IO address and should be presented as Memory Mapped IO in EFI Runtime mapping. This information can be used by OS when mapping the flash memory range.
It is especially helpful in SEV guest case, in which IO addresses should be mapped as unencrypted. If memory region is not marked as MMIO then OS maps the range as encrypted. Cc: Ard Biesheuvel <[email protected]> Cc: Anthony Perard <[email protected]> Cc: Julien Grall <[email protected]> Cc: Justen Jordan L <[email protected]> Cc: Laszlo Ersek <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Brijesh Singh <[email protected]> --- .../FwBlockService.c | 30 ++++++++++++++++------ 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockService.c b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockService.c index 558b395dff4a..b3f428bb4284 100644 --- a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockService.c +++ b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockService.c @@ -831,12 +831,13 @@ ValidateFvHeader ( STATIC EFI_STATUS -MarkMemoryRangeForRuntimeAccess ( +MarkIoMemoryRangeForRuntimeAccess ( EFI_PHYSICAL_ADDRESS BaseAddress, UINTN Length ) { EFI_STATUS Status; + EFI_GCD_MEMORY_SPACE_DESCRIPTOR GcdDescriptor; // // Mark flash region as runtime memory @@ -847,18 +848,31 @@ MarkMemoryRangeForRuntimeAccess ( ); Status = gDS->AddMemorySpace ( - EfiGcdMemoryTypeSystemMemory, + EfiGcdMemoryTypeMemoryMappedIo, BaseAddress, Length, EFI_MEMORY_UC | EFI_MEMORY_RUNTIME ); ASSERT_EFI_ERROR (Status); - Status = gBS->AllocatePages ( - AllocateAddress, - EfiRuntimeServicesData, - EFI_SIZE_TO_PAGES (Length), - &BaseAddress + Status = gDS->AllocateMemorySpace ( + EfiGcdAllocateAddress, + EfiGcdMemoryTypeMemoryMappedIo, + 0, + Length, + &BaseAddress, + gImageHandle, + NULL + ); + ASSERT_EFI_ERROR (Status); + + Status = gDS->GetMemorySpaceDescriptor (BaseAddress, &GcdDescriptor); + ASSERT_EFI_ERROR (Status); + + Status = gDS->SetMemorySpaceAttributes ( + BaseAddress, + Length, + GcdDescriptor.Attributes | EFI_MEMORY_RUNTIME ); ASSERT_EFI_ERROR (Status); @@ -1091,7 +1105,7 @@ FvbInitialize ( // InstallProtocolInterfaces (FvbDevice); - MarkMemoryRangeForRuntimeAccess (BaseAddress, Length); + MarkIoMemoryRangeForRuntimeAccess (BaseAddress, Length); // // Set several PCD values to point to flash -- 2.7.4 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
