OvmfPkg/PlatformInitLib: Add PlatformReservationConflictCB

[mirror_edk2.git] / OvmfPkg / Library / PlatformInitLib / MemDetect.c

diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
index c24105c329334f3563d98a95c8a5bfd89c3ad78d..6c30566db937188e359dec8bcb1c16abe5222538 100644 (file)
--- a/OvmfPkg/Library/PlatformInitLib/MemDetect.c
+++ b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
@@ -216,6 +216,51 @@ PlatformAddHobCB (
   }\r
 }\r
 \r
+/**\r
+  Check whenever the 64bit PCI MMIO window overlaps with a reservation\r
+  from qemu.  If so move down the MMIO window to resolve the conflict.\r
+\r
+  This happens on (virtual) AMD machines with 1TB address space,\r
+  because the AMD IOMMU uses an address window just below 1TB.\r
+**/\r
+STATIC\r
+VOID\r
+PlatformReservationConflictCB (\r
+  IN     EFI_E820_ENTRY64       *E820Entry,\r
+  IN OUT EFI_HOB_PLATFORM_INFO  *PlatformInfoHob\r
+  )\r
+{\r
+  UINT64  IntersectionBase;\r
+  UINT64  IntersectionEnd;\r
+  UINT64  NewBase;\r
+\r
+  IntersectionBase = MAX (\r
+                       E820Entry->BaseAddr,\r
+                       PlatformInfoHob->PcdPciMmio64Base\r
+                       );\r
+  IntersectionEnd = MIN (\r
+                      E820Entry->BaseAddr + E820Entry->Length,\r
+                      PlatformInfoHob->PcdPciMmio64Base +\r
+                      PlatformInfoHob->PcdPciMmio64Size\r
+                      );\r
+\r
+  if (IntersectionBase >= IntersectionEnd) {\r
+    return;  // no overlap\r
+  }\r
+\r
+  NewBase = E820Entry->BaseAddr - PlatformInfoHob->PcdPciMmio64Size;\r
+  NewBase = NewBase & ~(PlatformInfoHob->PcdPciMmio64Size - 1);\r
+\r
+  DEBUG ((\r
+    DEBUG_INFO,\r
+    "%a: move mmio: 0x%Lx => %Lx\n",\r
+    __FUNCTION__,\r
+    PlatformInfoHob->PcdPciMmio64Base,\r
+    NewBase\r
+    ));\r
+  PlatformInfoHob->PcdPciMmio64Base = NewBase;\r
+}\r
+\r
 /**\r
   Iterate over the entries in QEMU's fw_cfg E820 RAM map, call the\r
   passed callback for each entry.\r
@@ -653,6 +698,7 @@ PlatformDynamicMmioWindow (
     DEBUG ((DEBUG_INFO, "%a:   MMIO Space 0x%Lx (%Ld GB)\n", __func__, MmioSpace, RShiftU64 (MmioSpace, 30)));\r
     PlatformInfoHob->PcdPciMmio64Size = MmioSpace;\r
     PlatformInfoHob->PcdPciMmio64Base = AddrSpace - MmioSpace;\r
+    PlatformScanE820 (PlatformReservationConflictCB, PlatformInfoHob);\r
   } else {\r
     DEBUG ((DEBUG_INFO, "%a: using classic mmio window\n", __func__));\r
   }\r