OvmfPkg: Create GHCB pages for use during Pei and Dxe phase

[mirror_edk2.git] / OvmfPkg / PlatformPei / AmdSev.c

diff --git a/OvmfPkg/PlatformPei/AmdSev.c b/OvmfPkg/PlatformPei/AmdSev.c
index 4dc5340caa7a2814e8914ecfa7a3a6deb12acbd8..4fd4534cabeab8730434d8ee563f6bd7a26ec745 100644 (file)
--- a/OvmfPkg/PlatformPei/AmdSev.c
+++ b/OvmfPkg/PlatformPei/AmdSev.c
@@ -10,12 +10,15 @@
 // The package level header files this module uses\r
 //\r
 #include <IndustryStandard/Q35MchIch9.h>\r
+#include <Library/BaseMemoryLib.h>\r
 #include <Library/DebugLib.h>\r
 #include <Library/HobLib.h>\r
 #include <Library/MemEncryptSevLib.h>\r
+#include <Library/MemoryAllocationLib.h>\r
 #include <Library/PcdLib.h>\r
 #include <PiPei.h>\r
 #include <Register/Amd/Cpuid.h>\r
+#include <Register/Amd/Msr.h>\r
 #include <Register/Cpuid.h>\r
 #include <Register/Intel/SmramSaveStateMap.h>\r
 \r
@@ -32,7 +35,10 @@ AmdSevEsInitialize (
   VOID\r
   )\r
 {\r
-  RETURN_STATUS     PcdStatus;\r
+  VOID              *GhcbBase;\r
+  PHYSICAL_ADDRESS  GhcbBasePa;\r
+  UINTN             GhcbPageCount, PageCount;\r
+  RETURN_STATUS     PcdStatus, DecryptStatus;\r
 \r
   if (!MemEncryptSevEsIsEnabled ()) {\r
     return;\r
@@ -40,6 +46,43 @@ AmdSevEsInitialize (
 \r
   PcdStatus = PcdSetBoolS (PcdSevEsIsEnabled, TRUE);\r
   ASSERT_RETURN_ERROR (PcdStatus);\r
+\r
+  //\r
+  // Allocate GHCB and per-CPU variable pages.\r
+  //\r
+  GhcbPageCount = mMaxCpuCount * 2;\r
+  GhcbBase = AllocatePages (GhcbPageCount);\r
+  ASSERT (GhcbBase != NULL);\r
+\r
+  GhcbBasePa = (PHYSICAL_ADDRESS)(UINTN) GhcbBase;\r
+\r
+  //\r
+  // Each vCPU gets two consecutive pages, the first is the GHCB and the\r
+  // second is the per-CPU variable page. Loop through the allocation and\r
+  // only clear the encryption mask for the GHCB pages.\r
+  //\r
+  for (PageCount = 0; PageCount < GhcbPageCount; PageCount += 2) {\r
+    DecryptStatus = MemEncryptSevClearPageEncMask (\r
+      0,\r
+      GhcbBasePa + EFI_PAGES_TO_SIZE (PageCount),\r
+      1,\r
+      TRUE\r
+      );\r
+    ASSERT_RETURN_ERROR (DecryptStatus);\r
+  }\r
+\r
+  ZeroMem (GhcbBase, EFI_PAGES_TO_SIZE (GhcbPageCount));\r
+\r
+  PcdStatus = PcdSet64S (PcdGhcbBase, GhcbBasePa);\r
+  ASSERT_RETURN_ERROR (PcdStatus);\r
+  PcdStatus = PcdSet64S (PcdGhcbSize, EFI_PAGES_TO_SIZE (GhcbPageCount));\r
+  ASSERT_RETURN_ERROR (PcdStatus);\r
+\r
+  DEBUG ((DEBUG_INFO,\r
+    "SEV-ES is enabled, %lu GHCB pages allocated starting at 0x%p\n",\r
+    (UINT64)GhcbPageCount, GhcbBase));\r
+\r
+  AsmWriteMsr64 (MSR_SEV_ES_GHCB, GhcbBasePa);\r
 }\r
 \r
 /**\r