include/uapi/linux/qemu_fw_cfg.h

File Facts

System

Linux kernel

Corpus path

include/uapi/linux/qemu_fw_cfg.h

Extension

.h

Size

2469 bytes

Lines

98

Domain

Core OS

Bucket

Core Kernel Interface

Inferred role

Core OS: implementation source

Status

source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/types.h

Detected Declarations

• struct fw_cfg_file
• struct fw_cfg_dma_access
• struct fw_cfg_vmcoreinfo

Annotated Snippet

struct fw_cfg_file {
	__be32 size;
	__be16 select;
	__u16 reserved;
	char name[FW_CFG_MAX_FILE_PATH];
};

/* FW_CFG_DMA_CONTROL bits */
#define FW_CFG_DMA_CTL_ERROR	0x01
#define FW_CFG_DMA_CTL_READ	0x02
#define FW_CFG_DMA_CTL_SKIP	0x04
#define FW_CFG_DMA_CTL_SELECT	0x08
#define FW_CFG_DMA_CTL_WRITE	0x10

#define FW_CFG_DMA_SIGNATURE    0x51454d5520434647ULL /* "QEMU CFG" */

/* Control as first field allows for different structures selected by this
 * field, which might be useful in the future
 */
struct fw_cfg_dma_access {
	__be32 control;
	__be32 length;
	__be64 address;
};

#define FW_CFG_VMCOREINFO_FILENAME "etc/vmcoreinfo"

#define FW_CFG_VMCOREINFO_FORMAT_NONE 0x0
#define FW_CFG_VMCOREINFO_FORMAT_ELF 0x1

struct fw_cfg_vmcoreinfo {
	__le16 host_format;
	__le16 guest_format;
	__le32 size;
	__le64 paddr;
};

#endif

Annotation

• Immediate include surface: `linux/types.h`.
• Detected declarations: `struct fw_cfg_file`, `struct fw_cfg_dma_access`, `struct fw_cfg_vmcoreinfo`.
• Atlas domain: Core OS / Core Kernel Interface.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.