projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 1767877a LE |
1 | /** @file\r |
| 2 | OVMF support for QEMU system firmware flash device: functions specific to the\r | |
| 3 | runtime DXE driver build.\r | |
| 4 | \r | |
| 5 | Copyright (C) 2015, Red Hat, Inc.\r | |
| 6 | Copyright (c) 2009 - 2013, Intel Corporation. All rights reserved.<BR>\r | |
| 7 | \r | |
| b26f0cf9 | 8 | SPDX-License-Identifier: BSD-2-Clause-Patent\r |
| 1767877a LE |
9 | \r |
| 10 | **/\r | |
| 11 | \r | |
| 12 | #include <Library/UefiRuntimeLib.h>\r | |
| 437eb3f7 TL |
13 | #include <Library/MemEncryptSevLib.h>\r |
| 14 | #include <Library/VmgExitLib.h>\r | |
| 15 | #include <Register/Amd/Msr.h>\r | |
| 1767877a LE |
16 | \r |
| 17 | #include "QemuFlash.h"\r | |
| 18 | \r | |
| 19 | VOID\r | |
| 20 | QemuFlashConvertPointers (\r | |
| 21 | VOID\r | |
| 22 | )\r | |
| 23 | {\r | |
| 24 | EfiConvertPointer (0x0, (VOID **) &mFlashBase);\r | |
| 25 | }\r | |
| e4a1d5a7 BS |
26 | \r |
| 27 | VOID\r | |
| 28 | QemuFlashBeforeProbe (\r | |
| 29 | IN EFI_PHYSICAL_ADDRESS BaseAddress,\r | |
| 30 | IN UINTN FdBlockSize,\r | |
| 31 | IN UINTN FdBlockCount\r | |
| 32 | )\r | |
| 33 | {\r | |
| 34 | //\r | |
| 35 | // Do nothing\r | |
| 36 | //\r | |
| 37 | }\r | |
| 437eb3f7 TL |
38 | \r |
| 39 | /**\r | |
| 40 | Write to QEMU Flash\r | |
| 41 | \r | |
| 42 | @param[in] Ptr Pointer to the location to write.\r | |
| 43 | @param[in] Value The value to write.\r | |
| 44 | \r | |
| 45 | **/\r | |
| 46 | VOID\r | |
| 47 | QemuFlashPtrWrite (\r | |
| 48 | IN volatile UINT8 *Ptr,\r | |
| 49 | IN UINT8 Value\r | |
| 50 | )\r | |
| 51 | {\r | |
| 52 | if (MemEncryptSevEsIsEnabled ()) {\r | |
| 53 | MSR_SEV_ES_GHCB_REGISTER Msr;\r | |
| 54 | GHCB *Ghcb;\r | |
| 55 | \r | |
| 56 | Msr.GhcbPhysicalAddress = AsmReadMsr64 (MSR_SEV_ES_GHCB);\r | |
| 57 | Ghcb = Msr.Ghcb;\r | |
| 58 | \r | |
| 59 | //\r | |
| 60 | // Writing to flash is emulated by the hypervisor through the use of write\r | |
| 61 | // protection. This won't work for an SEV-ES guest because the write won't\r | |
| 62 | // be recognized as a true MMIO write, which would result in the required\r | |
| 63 | // #VC exception. Instead, use the the VMGEXIT MMIO write support directly\r | |
| 64 | // to perform the update.\r | |
| 65 | //\r | |
| 66 | VmgInit (Ghcb);\r | |
| 67 | Ghcb->SharedBuffer[0] = Value;\r | |
| 68 | Ghcb->SaveArea.SwScratch = (UINT64) (UINTN) Ghcb->SharedBuffer;\r | |
| 69 | VmgExit (Ghcb, SVM_EXIT_MMIO_WRITE, (UINT64) (UINTN) Ptr, 1);\r | |
| 70 | VmgDone (Ghcb);\r | |
| 71 | } else {\r | |
| 72 | *Ptr = Value;\r | |
| 73 | }\r | |
| 74 | }\r |