xref: /kvmtool/include/kvm/disk-image.h (revision f10860ca9c48f0ae9b988c4857944af20f9ffa39)
19f532d00SPekka Enberg #ifndef KVM__DISK_IMAGE_H
29f532d00SPekka Enberg #define KVM__DISK_IMAGE_H
39f532d00SPekka Enberg 
43fdf659dSSasha Levin #include <linux/types.h>
59ac38fe1SSasha Levin #include <stdbool.h>
670b53f25SSasha Levin #include <sys/uio.h>
79f532d00SPekka Enberg 
82924f993SAsias He #define SECTOR_SHIFT		9
92924f993SAsias He #define SECTOR_SIZE		(1UL << SECTOR_SHIFT)
102924f993SAsias He 
11499f3bedSPekka Enberg struct disk_image;
12499f3bedSPekka Enberg 
13499f3bedSPekka Enberg struct disk_image_operations {
1443835ac9SSasha Levin 	int (*read_sector)(struct disk_image *disk, u64 sector, void *dst, u32 dst_len);
1543835ac9SSasha Levin 	int (*write_sector)(struct disk_image *disk, u64 sector, void *src, u32 src_len);
1643835ac9SSasha Levin 	ssize_t (*read_sector_iov)(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
1743835ac9SSasha Levin 	ssize_t (*write_sector_iov)(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
1843835ac9SSasha Levin 	void (*close)(struct disk_image *disk);
19499f3bedSPekka Enberg };
20499f3bedSPekka Enberg 
219f532d00SPekka Enberg struct disk_image {
229f532d00SPekka Enberg 	int				fd;
233fdf659dSSasha Levin 	u64				size;
24499f3bedSPekka Enberg 	struct disk_image_operations	*ops;
25499f3bedSPekka Enberg 	void				*priv;
269f532d00SPekka Enberg };
279f532d00SPekka Enberg 
289ac38fe1SSasha Levin struct disk_image *disk_image__open(const char *filename, bool readonly);
293fdf659dSSasha Levin struct disk_image *disk_image__new(int fd, u64 size, struct disk_image_operations *ops);
303fdf659dSSasha Levin struct disk_image *disk_image__new_readonly(int fd, u64 size, struct disk_image_operations *ops);
3143835ac9SSasha Levin void disk_image__close(struct disk_image *disk);
32499f3bedSPekka Enberg 
3343835ac9SSasha Levin static inline int disk_image__read_sector(struct disk_image *disk, u64 sector, void *dst, u32 dst_len)
34499f3bedSPekka Enberg {
3543835ac9SSasha Levin 	return disk->ops->read_sector(disk, sector, dst, dst_len);
36499f3bedSPekka Enberg }
37499f3bedSPekka Enberg 
3843835ac9SSasha Levin static inline int disk_image__write_sector(struct disk_image *disk, u64 sector, void *src, u32 src_len)
39499f3bedSPekka Enberg {
4043835ac9SSasha Levin 	return disk->ops->write_sector(disk, sector, src, src_len);
41499f3bedSPekka Enberg }
429f532d00SPekka Enberg 
4343835ac9SSasha Levin static inline ssize_t disk_image__read_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
4470b53f25SSasha Levin {
4543835ac9SSasha Levin 	if (disk->ops->read_sector_iov)
4643835ac9SSasha Levin 		return disk->ops->read_sector_iov(disk, sector, iov, iovcount);
4770b53f25SSasha Levin 
4870b53f25SSasha Levin 	while (iovcount--) {
49*f10860caSPekka Enberg 		if (disk->ops->read_sector(disk, sector, iov->iov_base, iov->iov_len) < 0)
50*f10860caSPekka Enberg 			return -1;
51*f10860caSPekka Enberg 
5270b53f25SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
5370b53f25SSasha Levin 		iov++;
5470b53f25SSasha Levin 	}
5570b53f25SSasha Levin 
5670b53f25SSasha Levin 	return sector << SECTOR_SHIFT;
5770b53f25SSasha Levin }
5870b53f25SSasha Levin 
5943835ac9SSasha Levin static inline ssize_t disk_image__write_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
6070b53f25SSasha Levin {
6143835ac9SSasha Levin 	if (disk->ops->write_sector_iov)
6243835ac9SSasha Levin 		return disk->ops->write_sector_iov(disk, sector, iov, iovcount);
6370b53f25SSasha Levin 
6470b53f25SSasha Levin 	while (iovcount--) {
65*f10860caSPekka Enberg 		if (disk->ops->write_sector(disk, sector, iov->iov_base, iov->iov_len) < 0)
66*f10860caSPekka Enberg 			return -1;
67*f10860caSPekka Enberg 
6870b53f25SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
6970b53f25SSasha Levin 		iov++;
7070b53f25SSasha Levin 	}
7170b53f25SSasha Levin 
7270b53f25SSasha Levin 	return sector << SECTOR_SHIFT;
7370b53f25SSasha Levin }
7470b53f25SSasha Levin 
759f532d00SPekka Enberg #endif /* KVM__DISK_IMAGE_H */
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