QemuFwCfgDxe.c File Reference

#include <Uefi.h>
#include <Protocol/IoMmu.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/IoLib.h>
#include <Library/DebugLib.h>
#include <Library/QemuFwCfgLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/MemEncryptTdxLib.h>
#include <Library/MemEncryptSevLib.h>
#include "QemuFwCfgLibInternal.h"

Go to the source code of this file.

Functions
BOOLEAN EFIAPI	QemuFwCfgIsAvailable (VOID)
RETURN_STATUS EFIAPI	QemuFwCfgInitialize (VOID)
BOOLEAN	InternalQemuFwCfgIsAvailable (VOID)
BOOLEAN	InternalQemuFwCfgDmaIsAvailable (VOID)
STATIC VOID	AllocFwCfgDmaAccessBuffer (OUT VOID **Access, OUT VOID **MapInfo)
STATIC VOID	FreeFwCfgDmaAccessBuffer (IN VOID *Access, IN VOID *Mapping)
STATIC VOID	MapFwCfgDmaDataBuffer (IN BOOLEAN IsWrite, IN VOID *HostAddress, IN UINT32 Size, OUT EFI_PHYSICAL_ADDRESS *DeviceAddress, OUT VOID **MapInfo)
STATIC VOID	UnmapFwCfgDmaDataBuffer (IN VOID *Mapping)
VOID	InternalQemuFwCfgDmaBytes (IN UINT32 Size, IN OUT VOID *Buffer OPTIONAL, IN UINT32 Control)

Variables
STATIC BOOLEAN	mQemuFwCfgSupported = FALSE
STATIC BOOLEAN	mQemuFwCfgDmaSupported
STATIC EDKII_IOMMU_PROTOCOL *	mIoMmuProtocol

Detailed Description

Stateful and implicitly initialized fw_cfg library implementation.

Copyright (C) 2013, Red Hat, Inc. Copyright (c) 2011 - 2013, Intel Corporation. All rights reserved.
Copyright (c) 2017, Advanced Micro Devices. All rights reserved.

SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file QemuFwCfgDxe.c.

Function Documentation

AllocFwCfgDmaAccessBuffer()

STATIC VOID AllocFwCfgDmaAccessBuffer	(	OUT VOID **	Access,
		OUT VOID **	MapInfo
	)

Function is used for allocating a bi-directional FW_CFG_DMA_ACCESS used between Host and device to exchange the information. The buffer must be free'd using FreeFwCfgDmaAccessBuffer ().

Definition at line 156 of file QemuFwCfgDxe.c.

FreeFwCfgDmaAccessBuffer()

STATIC VOID FreeFwCfgDmaAccessBuffer	(	IN VOID *	Access,
		IN VOID *	Mapping
	)

Function is to used for freeing the Access buffer allocated using AllocFwCfgDmaAccessBuffer()

Definition at line 250 of file QemuFwCfgDxe.c.

InternalQemuFwCfgDmaBytes()

VOID InternalQemuFwCfgDmaBytes	(	IN UINT32	Size,
		IN OUT VOID *Buffer	OPTIONAL,
		IN UINT32	Control
	)

Transfer an array of bytes, or skip a number of bytes, using the DMA interface.

Parameters

[in]	Size	Size in bytes to transfer or skip.
[in,out]	Buffer	Buffer to read data into or write data from. Ignored, and may be NULL, if Size is zero, or Control is FW_CFG_DMA_CTL_SKIP.
[in]	Control	One of the following: FW_CFG_DMA_CTL_WRITE - write to fw_cfg from Buffer. FW_CFG_DMA_CTL_READ - read from fw_cfg into Buffer. FW_CFG_DMA_CTL_SKIP - skip bytes in fw_cfg.

Definition at line 387 of file QemuFwCfgDxe.c.

InternalQemuFwCfgDmaIsAvailable()

BOOLEAN InternalQemuFwCfgDmaIsAvailable

(

VOID

)

Returns a boolean indicating whether QEMU provides the DMA-like access method for fw_cfg.

Return values

TRUE	The DMA-like access method is available.
FALSE	The DMA-like access method is unavailable.

Definition at line 141 of file QemuFwCfgDxe.c.

InternalQemuFwCfgIsAvailable()

BOOLEAN InternalQemuFwCfgIsAvailable

(

VOID

)

Returns a boolean indicating if the firmware configuration interface is available for library-internal purposes.

This function never changes fw_cfg state.

Return values

TRUE	The interface is available internally.
FALSE	The interface is not available internally.

Definition at line 126 of file QemuFwCfgDxe.c.

MapFwCfgDmaDataBuffer()

STATIC VOID MapFwCfgDmaDataBuffer	(	IN BOOLEAN	IsWrite,
		IN VOID *	HostAddress,
		IN UINT32	Size,
		OUT EFI_PHYSICAL_ADDRESS *	DeviceAddress,
		OUT VOID **	MapInfo
	)

Function is used for mapping host address to device address. The buffer must be unmapped with UnmapDmaDataBuffer ().

Definition at line 294 of file QemuFwCfgDxe.c.

QemuFwCfgInitialize()

RETURN_STATUS EFIAPI QemuFwCfgInitialize

(

VOID

)

Definition at line 53 of file QemuFwCfgDxe.c.

QemuFwCfgIsAvailable()

BOOLEAN EFIAPI QemuFwCfgIsAvailable

(

VOID

)

Returns a boolean indicating if the firmware configuration interface is available or not.

This function may change fw_cfg state.

Return values

TRUE	The interface is available
FALSE	The interface is not available

Definition at line 44 of file QemuFwCfgDxe.c.

UnmapFwCfgDmaDataBuffer()

STATIC VOID UnmapFwCfgDmaDataBuffer

(

IN VOID *

Mapping

)

Definition at line 351 of file QemuFwCfgDxe.c.

Variable Documentation

mIoMmuProtocol

STATIC EDKII_IOMMU_PROTOCOL* mIoMmuProtocol

Definition at line 30 of file QemuFwCfgDxe.c.

mQemuFwCfgDmaSupported

STATIC BOOLEAN mQemuFwCfgDmaSupported

Definition at line 28 of file QemuFwCfgDxe.c.

mQemuFwCfgSupported

STATIC BOOLEAN mQemuFwCfgSupported = FALSE

Definition at line 27 of file QemuFwCfgDxe.c.