include/xen/interface/io/blkif.h

Source file repositories/reference/linux-study-clean/include/xen/interface/io/blkif.h

File Facts

System
Linux kernel
Corpus path
include/xen/interface/io/blkif.h
Extension
.h
Size
13202 bytes
Lines
303
Domain
Repository Root And Misc
Bucket
include
Inferred role
Repository Root And Misc: implementation source
Status
source implementation candidate

Why This File Exists

Top-level or miscellaneous repository surface. Use this as map coverage unless a later manual pass promotes the file into a deeper subsystem dossier.

Dependency Surface

Detected Declarations

Annotated Snippet

struct blkif_request_segment {
		grant_ref_t gref;        /* reference to I/O buffer frame        */
		/* @first_sect: first sector in frame to transfer (inclusive).   */
		/* @last_sect: last sector in frame to transfer (inclusive).     */
		uint8_t     first_sect, last_sect;
};

struct blkif_request_rw {
	uint8_t        nr_segments;  /* number of segments                   */
	blkif_vdev_t   handle;       /* only for read/write requests         */
#ifndef CONFIG_X86_32
	uint32_t       _pad1;	     /* offsetof(blkif_request,u.rw.id) == 8 */
#endif
	uint64_t       id;           /* private guest value, echoed in resp  */
	blkif_sector_t sector_number;/* start sector idx on disk (r/w only)  */
	struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
} __attribute__((__packed__));

struct blkif_request_discard {
	uint8_t        flag;         /* BLKIF_DISCARD_SECURE or zero.        */
#define BLKIF_DISCARD_SECURE (1<<0)  /* ignored if discard-secure=0          */
	blkif_vdev_t   _pad1;        /* only for read/write requests         */
#ifndef CONFIG_X86_32
	uint32_t       _pad2;        /* offsetof(blkif_req..,u.discard.id)==8*/
#endif
	uint64_t       id;           /* private guest value, echoed in resp  */
	blkif_sector_t sector_number;
	uint64_t       nr_sectors;
	uint8_t        _pad3;
} __attribute__((__packed__));

struct blkif_request_other {
	uint8_t      _pad1;
	blkif_vdev_t _pad2;        /* only for read/write requests         */
#ifndef CONFIG_X86_32
	uint32_t     _pad3;        /* offsetof(blkif_req..,u.other.id)==8*/
#endif
	uint64_t     id;           /* private guest value, echoed in resp  */
} __attribute__((__packed__));

struct blkif_request_indirect {
	uint8_t        indirect_op;
	uint16_t       nr_segments;
#ifndef CONFIG_X86_32
	uint32_t       _pad1;        /* offsetof(blkif_...,u.indirect.id) == 8 */
#endif
	uint64_t       id;
	blkif_sector_t sector_number;
	blkif_vdev_t   handle;
	uint16_t       _pad2;
	grant_ref_t    indirect_grefs[BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST];
#ifndef CONFIG_X86_32
	uint32_t      _pad3;         /* make it 64 byte aligned */
#else
	uint64_t      _pad3;         /* make it 64 byte aligned */
#endif
} __attribute__((__packed__));

struct blkif_request {
	uint8_t        operation;    /* BLKIF_OP_???                         */
	union {
		struct blkif_request_rw rw;
		struct blkif_request_discard discard;
		struct blkif_request_other other;
		struct blkif_request_indirect indirect;
	} u;
} __attribute__((__packed__));

struct blkif_response {
	uint64_t        id;              /* copied from request */
	uint8_t         operation;       /* copied from request */
	int16_t         status;          /* BLKIF_RSP_???       */
};

/*
 * STATUS RETURN CODES.
 */
 /* Operation not supported (only happens on barrier writes). */
#define BLKIF_RSP_EOPNOTSUPP  -2
 /* Operation failed for some unspecified reason (-EIO). */
#define BLKIF_RSP_ERROR       -1
 /* Operation completed successfully. */
#define BLKIF_RSP_OKAY         0

/*
 * Generate blkif ring structures and types.
 */

DEFINE_RING_TYPES(blkif, struct blkif_request, struct blkif_response);

Annotation

Implementation Notes