diff --git a/OvmfPkg/Include/Library/QemuFwCfgS3Lib.h b/OvmfPkg/Include/Library/QemuFwCfgS3Lib.h index 1c473610d1..76c8554cb7 100644 --- a/OvmfPkg/Include/Library/QemuFwCfgS3Lib.h +++ b/OvmfPkg/Include/Library/QemuFwCfgS3Lib.h @@ -19,6 +19,8 @@ #ifndef __FW_CFG_S3_LIB__ #define __FW_CFG_S3_LIB__ +#include + /** Determine if S3 support is explicitly enabled. @@ -36,4 +38,324 @@ QemuFwCfgS3Enabled ( VOID ); + +/** + Prototype for the callback function that the client module provides. + + In the callback function, the client module calls the + QemuFwCfgS3ScriptWriteBytes(), QemuFwCfgS3ScriptReadBytes(), + QemuFwCfgS3ScriptSkipBytes(), and QemuFwCfgS3ScriptCheckValue() functions. + Those functions produce ACPI S3 Boot Script opcodes that will perform fw_cfg + DMA operations, and will check any desired values that were read, during S3 + resume. + + The callback function is invoked when the production of ACPI S3 Boot Script + opcodes becomes possible. This may occur directly on the call stack of + QemuFwCfgS3CallWhenBootScriptReady() (see below), or after + QemuFwCfgS3CallWhenBootScriptReady() has successfully returned. + + The callback function must not return if it fails -- in the general case, + there is noone to propagate any errors to. Therefore, on error, an error + message should be logged, and CpuDeadLoop() must be called. + + @param[in,out] Context Carries information from the client module + itself (i.e., from the invocation of + QemuFwCfgS3CallWhenBootScriptReady()) to the + callback function. + + If Context points to dynamically allocated + storage, then the callback function must + release it. + + @param[in,out] ScratchBuffer Points to reserved memory, allocated by + QemuFwCfgS3CallWhenBootScriptReady() + internally. + + ScratchBuffer is typed and sized by the client + module when it calls + QemuFwCfgS3CallWhenBootScriptReady(). The + client module defines a union type of + structures for ScratchBuffer such that the + union can hold client data for any desired + fw_cfg DMA read and write operations, and value + checking. + + The callback function casts ScratchBuffer to + the union type described above. It passes union + member sizes as NumberOfBytes to + QemuFwCfgS3ScriptReadBytes() and + QemuFwCfgS3ScriptWriteBytes(). It passes field + addresses and sizes in structures in the union + as ScratchData and ValueSize to + QemuFwCfgS3ScriptCheckValue(). + + ScratchBuffer is aligned at 8 bytes. +**/ +typedef +VOID (EFIAPI FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION) ( + IN OUT VOID *Context, OPTIONAL + IN OUT VOID *ScratchBuffer + ); + + +/** + Install the client module's FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION callback for + when the production of ACPI S3 Boot Script opcodes becomes possible. + + Take ownership of the client-provided Context, and pass it to the callback + function, when the latter is invoked. + + Allocate scratch space for those ACPI S3 Boot Script opcodes to work upon + that the client will produce in the callback function. + + @param[in] Callback FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION to invoke + when the production of ACPI S3 Boot Script + opcodes becomes possible. Callback() may be + called immediately from + QemuFwCfgS3CallWhenBootScriptReady(). + + @param[in,out] Context Client-provided data structure for the + Callback() callback function to consume. + + If Context points to dynamically allocated + memory, then Callback() must release it. + + If Context points to dynamically allocated + memory, and + QemuFwCfgS3CallWhenBootScriptReady() returns + successfully, then the caller of + QemuFwCfgS3CallWhenBootScriptReady() must + neither dereference nor even evaluate Context + any longer, as ownership of the referenced area + has been transferred to Callback(). + + @param[in] ScratchBufferSize The size of the scratch buffer that will hold, + in reserved memory, all client data read, + written, and checked by the ACPI S3 Boot Script + opcodes produced by Callback(). + + @retval RETURN_UNSUPPORTED The library instance does not support this + function. + + @retval RETURN_NOT_FOUND The fw_cfg DMA interface to QEMU is + unavailable. + + @retval RETURN_BAD_BUFFER_SIZE ScratchBufferSize is too large. + + @retval RETURN_OUT_OF_RESOURCES Memory allocation failed. + + @retval RETURN_SUCCESS Callback() has been installed, and the + ownership of Context has been transferred. + Reserved memory has been allocated for the + scratch buffer. + + A successful invocation of + QemuFwCfgS3CallWhenBootScriptReady() cannot + be rolled back. + + @return Error codes from underlying functions. +**/ +EFIAPI +RETURN_STATUS +QemuFwCfgS3CallWhenBootScriptReady ( + IN FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION *Callback, + IN OUT VOID *Context, OPTIONAL + IN UINTN ScratchBufferSize + ); + + +/** + Produce ACPI S3 Boot Script opcodes that (optionally) select an fw_cfg item, + and transfer data to it. + + The opcodes produced by QemuFwCfgS3ScriptWriteBytes() will first restore + NumberOfBytes bytes in ScratchBuffer in-place, in reserved memory, then write + them to fw_cfg using DMA. + + If the operation fails during S3 resume, the boot script will hang. + + This function may only be called from the client module's + FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION, which was passed to + QemuFwCfgS3CallWhenBootScriptReady() as Callback. + + @param[in] FirmwareConfigItem The UINT16 selector key of the firmware config + item to write, expressed as INT32. If + FirmwareConfigItem is -1, no selection is + made, the write will occur to the currently + selected item, at its currently selected + offset. Otherwise, the specified item will be + selected, and the write will occur at offset + 0. + + @param[in] NumberOfBytes Size of the data to restore in ScratchBuffer, + and to write from ScratchBuffer, during S3 + resume. NumberOfBytes must not exceed + ScratchBufferSize, which was passed to + QemuFwCfgS3CallWhenBootScriptReady(). + + @retval RETURN_SUCCESS The opcodes were appended to the ACPI S3 + Boot Script successfully. There is no way + to undo this action. + + @retval RETURN_INVALID_PARAMETER FirmwareConfigItem is invalid. + + @retval RETURN_BAD_BUFFER_SIZE NumberOfBytes is larger than + ScratchBufferSize. + + @return Error codes from underlying functions. +**/ +EFIAPI +RETURN_STATUS +QemuFwCfgS3ScriptWriteBytes ( + IN INT32 FirmwareConfigItem, + IN UINTN NumberOfBytes + ); + + +/** + Produce ACPI S3 Boot Script opcodes that (optionally) select an fw_cfg item, + and transfer data from it. + + The opcodes produced by QemuFwCfgS3ScriptReadBytes() will read NumberOfBytes + bytes from fw_cfg using DMA, storing the result in ScratchBuffer, in reserved + memory. + + If the operation fails during S3 resume, the boot script will hang. + + This function may only be called from the client module's + FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION, which was passed to + QemuFwCfgS3CallWhenBootScriptReady() as Callback. + + @param[in] FirmwareConfigItem The UINT16 selector key of the firmware config + item to read, expressed as INT32. If + FirmwareConfigItem is -1, no selection is + made, the read will occur from the currently + selected item, from its currently selected + offset. Otherwise, the specified item will be + selected, and the read will occur from offset + 0. + + @param[in] NumberOfBytes Size of the data to read during S3 resume. + NumberOfBytes must not exceed + ScratchBufferSize, which was passed to + QemuFwCfgS3CallWhenBootScriptReady(). + + @retval RETURN_SUCCESS The opcodes were appended to the ACPI S3 + Boot Script successfully. There is no way + to undo this action. + + @retval RETURN_INVALID_PARAMETER FirmwareConfigItem is invalid. + + @retval RETURN_BAD_BUFFER_SIZE NumberOfBytes is larger than + ScratchBufferSize. + + @return Error codes from underlying functions. +**/ +EFIAPI +RETURN_STATUS +QemuFwCfgS3ScriptReadBytes ( + IN INT32 FirmwareConfigItem, + IN UINTN NumberOfBytes + ); + + +/** + Produce ACPI S3 Boot Script opcodes that (optionally) select an fw_cfg item, + and increase its offset. + + If the operation fails during S3 resume, the boot script will hang. + + This function may only be called from the client module's + FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION, which was passed to + QemuFwCfgS3CallWhenBootScriptReady() as Callback. + + @param[in] FirmwareConfigItem The UINT16 selector key of the firmware config + item to advance the offset of, expressed as + INT32. If FirmwareConfigItem is -1, no + selection is made, and the offset for the + currently selected item is increased. + Otherwise, the specified item will be + selected, and the offset increment will occur + from offset 0. + + @param[in] NumberOfBytes The number of bytes to skip in the subject + fw_cfg item. + + @retval RETURN_SUCCESS The opcodes were appended to the ACPI S3 + Boot Script successfully. There is no way + to undo this action. + + @retval RETURN_INVALID_PARAMETER FirmwareConfigItem is invalid. + + @retval RETURN_BAD_BUFFER_SIZE NumberOfBytes is too large. + + @return Error codes from underlying functions. +**/ +EFIAPI +RETURN_STATUS +QemuFwCfgS3ScriptSkipBytes ( + IN INT32 FirmwareConfigItem, + IN UINTN NumberOfBytes + ); + + +/** + Produce ACPI S3 Boot Script opcodes that check a value in ScratchBuffer. + + If the check fails during S3 resume, the boot script will hang. + + This function may only be called from the client module's + FW_CFG_BOOT_SCRIPT_CALLBACK_FUNCTION, which was passed to + QemuFwCfgS3CallWhenBootScriptReady() as Callback. + + @param[in] ScratchData Pointer to the UINT8, UINT16, UINT32 or UINT64 field + in ScratchBuffer that should be checked. The caller + is responsible for populating the field during S3 + resume, by calling QemuFwCfgS3ScriptReadBytes() ahead + of QemuFwCfgS3ScriptCheckValue(). + + ScratchData must point into ScratchBuffer, which was + allocated, and passed to Callback(), by + QemuFwCfgS3CallWhenBootScriptReady(). + + ScratchData must be aligned at ValueSize bytes. + + @param[in] ValueSize One of 1, 2, 4 or 8, specifying the size of the field + to check. + + @param[in] ValueMask The value read from ScratchData is binarily AND-ed + with ValueMask, and the result is compared against + Value. If the masked data equals Value, the check + passes, and the boot script can proceed. Otherwise, + the check fails, and the boot script hangs. + + @param[in] Value Refer to ValueMask. + + @retval RETURN_SUCCESS The opcodes were appended to the ACPI S3 + Boot Script successfully. There is no way + to undo this action. + + @retval RETURN_INVALID_PARAMETER ValueSize is invalid. + + @retval RETURN_INVALID_PARAMETER ValueMask or Value cannot be represented in + ValueSize bytes. + + @retval RETURN_INVALID_PARAMETER ScratchData is not aligned at ValueSize + bytes. + + @retval RETURN_BAD_BUFFER_SIZE The ValueSize bytes at ScratchData aren't + wholly contained in the ScratchBufferSize + bytes at ScratchBuffer. + + @return Error codes from underlying functions. +**/ +EFIAPI +RETURN_STATUS +QemuFwCfgS3ScriptCheckValue ( + IN VOID *ScratchData, + IN UINT8 ValueSize, + IN UINT64 ValueMask, + IN UINT64 Value + ); + #endif