From 966363d5a34839399e3d9f68d4f4efb4b1a9ec66 Mon Sep 17 00:00:00 2001
From: Brijesh Singh <brijesh.singh@amd.com>
Date: Fri, 6 Jul 2018 10:00:40 -0500
Subject: [PATCH] OvmfPkg/QemuFlashFvbServicesRuntimeDxe: mark Flash memory
 range as MMIO

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 <ard.biesheuvel@linaro.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Julien Grall <julien.grall@linaro.org>
Cc: Justen Jordan L <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
---
 .../FwBlockService.c                          | 30 ++++++++++++++-----
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockService.c b/OvmfPkg/QemuFlashFvbServicesRuntimeDxe/FwBlockService.c
index 558b395dff..b3f428bb42 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
-- 
2.39.2