OvmfPkg/MemEncryptSevLib: find pages of initial SMRAM save state map

[mirror_edk2.git] / OvmfPkg / Library / QemuFwCfgLib / QemuFwCfgLib.c

diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
index a228c029dfb909edadb3247017264c182ea6f0e7..7f42f38d1c05cca65225e962b5d530dd01a1daed 100644 (file)
--- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
@@ -42,74 +42,9 @@ QemuFwCfgSelectItem (
   )\r
 {\r
   DEBUG ((EFI_D_INFO, "Select Item: 0x%x\n", (UINT16)(UINTN) QemuFwCfgItem));\r
-  IoWrite16 (0x510, (UINT16)(UINTN) QemuFwCfgItem);\r
+  IoWrite16 (FW_CFG_IO_SELECTOR, (UINT16)(UINTN) QemuFwCfgItem);\r
 }\r
 \r
-\r
-/**\r
-  Transfer an array of bytes using the DMA interface.\r
-\r
-  @param[in]     Size    Size in bytes to transfer.\r
-  @param[in,out] Buffer  Buffer to read data into or write data from. May be\r
-                         NULL if Size is zero.\r
-  @param[in]     Write   TRUE if writing to fw_cfg from Buffer, FALSE if\r
-                         reading from fw_cfg into Buffer.\r
-**/\r
-VOID\r
-InternalQemuFwCfgDmaBytes (\r
-  IN     UINT32   Size,\r
-  IN OUT VOID     *Buffer OPTIONAL,\r
-  IN     BOOLEAN  Write\r
-  )\r
-{\r
-  volatile FW_CFG_DMA_ACCESS Access;\r
-  UINT32                     AccessHigh, AccessLow;\r
-  UINT32                     Status;\r
-\r
-  if (Size == 0) {\r
-    return;\r
-  }\r
-\r
-  Access.Control = SwapBytes32 (\r
-                    Write ? FW_CFG_DMA_CTL_WRITE : FW_CFG_DMA_CTL_READ\r
-                    );\r
-  Access.Length  = SwapBytes32 (Size);\r
-  Access.Address = SwapBytes64 ((UINTN)Buffer);\r
-\r
-  //\r
-  // Delimit the transfer from (a) modifications to Access, (b) in case of a\r
-  // write, from writes to Buffer by the caller.\r
-  //\r
-  MemoryFence ();\r
-\r
-  //\r
-  // Start the transfer.\r
-  //\r
-  AccessHigh = (UINT32)RShiftU64 ((UINTN)&Access, 32);\r
-  AccessLow  = (UINT32)(UINTN)&Access;\r
-  IoWrite32 (0x514, SwapBytes32 (AccessHigh));\r
-  IoWrite32 (0x518, SwapBytes32 (AccessLow));\r
-\r
-  //\r
-  // Don't look at Access.Control before starting the transfer.\r
-  //\r
-  MemoryFence ();\r
-\r
-  //\r
-  // Wait for the transfer to complete.\r
-  //\r
-  do {\r
-    Status = SwapBytes32 (Access.Control);\r
-    ASSERT ((Status & FW_CFG_DMA_CTL_ERROR) == 0);\r
-  } while (Status != 0);\r
-\r
-  //\r
-  // After a read, the caller will want to use Buffer.\r
-  //\r
-  MemoryFence ();\r
-}\r
-\r
-\r
 /**\r
   Reads firmware configuration bytes into a buffer\r
 \r
@@ -125,10 +60,10 @@ InternalQemuFwCfgReadBytes (
   )\r
 {\r
   if (InternalQemuFwCfgDmaIsAvailable () && Size <= MAX_UINT32) {\r
-    InternalQemuFwCfgDmaBytes ((UINT32)Size, Buffer, FALSE);\r
+    InternalQemuFwCfgDmaBytes ((UINT32)Size, Buffer, FW_CFG_DMA_CTL_READ);\r
     return;\r
   }\r
-  IoReadFifo8 (0x511, Size, Buffer);\r
+  IoReadFifo8 (FW_CFG_IO_DATA, Size, Buffer);\r
 }\r
 \r
 \r
@@ -177,10 +112,54 @@ QemuFwCfgWriteBytes (
 {\r
   if (InternalQemuFwCfgIsAvailable ()) {\r
     if (InternalQemuFwCfgDmaIsAvailable () && Size <= MAX_UINT32) {\r
-      InternalQemuFwCfgDmaBytes ((UINT32)Size, Buffer, TRUE);\r
+      InternalQemuFwCfgDmaBytes ((UINT32)Size, Buffer, FW_CFG_DMA_CTL_WRITE);\r
       return;\r
     }\r
-    IoWriteFifo8 (0x511, Size, Buffer);\r
+    IoWriteFifo8 (FW_CFG_IO_DATA, Size, Buffer);\r
+  }\r
+}\r
+\r
+\r
+/**\r
+  Skip bytes in the firmware configuration item.\r
+\r
+  Increase the offset of the firmware configuration item without transferring\r
+  bytes between the item and a caller-provided buffer. Subsequent read, write\r
+  or skip operations will commence at the increased offset.\r
+\r
+  @param[in] Size  Number of bytes to skip.\r
+**/\r
+VOID\r
+EFIAPI\r
+QemuFwCfgSkipBytes (\r
+  IN UINTN                  Size\r
+  )\r
+{\r
+  UINTN ChunkSize;\r
+  UINT8 SkipBuffer[256];\r
+\r
+  if (!InternalQemuFwCfgIsAvailable ()) {\r
+    return;\r
+  }\r
+\r
+  if (InternalQemuFwCfgDmaIsAvailable () && Size <= MAX_UINT32) {\r
+    InternalQemuFwCfgDmaBytes ((UINT32)Size, NULL, FW_CFG_DMA_CTL_SKIP);\r
+    return;\r
+  }\r
+\r
+  //\r
+  // Emulate the skip by reading data in chunks, and throwing it away. The\r
+  // implementation below is suitable even for phases where RAM or dynamic\r
+  // allocation is not available or appropriate. It also doesn't affect the\r
+  // static data footprint for client modules. Large skips are not expected,\r
+  // therefore this fallback is not performance critical. The size of\r
+  // SkipBuffer is thought not to exert a large pressure on the stack in any\r
+  // phase.\r
+  //\r
+  while (Size > 0) {\r
+    ChunkSize = MIN (Size, sizeof SkipBuffer);\r
+    IoReadFifo8 (FW_CFG_IO_DATA, ChunkSize, SkipBuffer);\r
+    Size -= ChunkSize;\r
   }\r
 }\r
 \r
@@ -317,31 +296,3 @@ QemuFwCfgFindFile (
 \r
   return RETURN_NOT_FOUND;\r
 }\r
-\r
-\r
-/**\r
-  Determine if S3 support is explicitly enabled.\r
-\r
-  @retval  TRUE   if S3 support is explicitly enabled.\r
-           FALSE  otherwise. This includes unavailability of the firmware\r
-                  configuration interface.\r
-**/\r
-BOOLEAN\r
-EFIAPI\r
-QemuFwCfgS3Enabled (\r
-  VOID\r
-  )\r
-{\r
-  RETURN_STATUS        Status;\r
-  FIRMWARE_CONFIG_ITEM FwCfgItem;\r
-  UINTN                FwCfgSize;\r
-  UINT8                SystemStates[6];\r
-\r
-  Status = QemuFwCfgFindFile ("etc/system-states", &FwCfgItem, &FwCfgSize);\r
-  if (Status != RETURN_SUCCESS || FwCfgSize != sizeof SystemStates) {\r
-    return FALSE;\r
-  }\r
-  QemuFwCfgSelectItem (FwCfgItem);\r
-  QemuFwCfgReadBytes (sizeof SystemStates, SystemStates);\r
-  return (BOOLEAN) (SystemStates[3] & BIT7);\r
-}\r