xref: /kvmtool/include/kvm/disk-image.h (revision 29084a74e900c2760f37827fea7b9c2050f253ed)
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>
7*29084a74SPrasad Joshi #include <unistd.h>
89f532d00SPekka Enberg 
92924f993SAsias He #define SECTOR_SHIFT		9
102924f993SAsias He #define SECTOR_SIZE		(1UL << SECTOR_SHIFT)
112924f993SAsias He 
12499f3bedSPekka Enberg struct disk_image;
13499f3bedSPekka Enberg 
14499f3bedSPekka Enberg struct disk_image_operations {
1543835ac9SSasha Levin 	int (*read_sector)(struct disk_image *disk, u64 sector, void *dst, u32 dst_len);
1643835ac9SSasha Levin 	int (*write_sector)(struct disk_image *disk, u64 sector, void *src, u32 src_len);
1743835ac9SSasha Levin 	ssize_t (*read_sector_iov)(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
1843835ac9SSasha Levin 	ssize_t (*write_sector_iov)(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount);
19*29084a74SPrasad Joshi 	int (*flush)(struct disk_image *disk);
2043835ac9SSasha Levin 	void (*close)(struct disk_image *disk);
21499f3bedSPekka Enberg };
22499f3bedSPekka Enberg 
239f532d00SPekka Enberg struct disk_image {
249f532d00SPekka Enberg 	int				fd;
253fdf659dSSasha Levin 	u64				size;
26499f3bedSPekka Enberg 	struct disk_image_operations	*ops;
27499f3bedSPekka Enberg 	void				*priv;
289f532d00SPekka Enberg };
299f532d00SPekka Enberg 
309ac38fe1SSasha Levin struct disk_image *disk_image__open(const char *filename, bool readonly);
313fdf659dSSasha Levin struct disk_image *disk_image__new(int fd, u64 size, struct disk_image_operations *ops);
323fdf659dSSasha Levin struct disk_image *disk_image__new_readonly(int fd, u64 size, struct disk_image_operations *ops);
3343835ac9SSasha Levin void disk_image__close(struct disk_image *disk);
34499f3bedSPekka Enberg 
3543835ac9SSasha Levin static inline int disk_image__read_sector(struct disk_image *disk, u64 sector, void *dst, u32 dst_len)
36499f3bedSPekka Enberg {
3743835ac9SSasha Levin 	return disk->ops->read_sector(disk, sector, dst, dst_len);
38499f3bedSPekka Enberg }
39499f3bedSPekka Enberg 
4043835ac9SSasha Levin static inline int disk_image__write_sector(struct disk_image *disk, u64 sector, void *src, u32 src_len)
41499f3bedSPekka Enberg {
4243835ac9SSasha Levin 	return disk->ops->write_sector(disk, sector, src, src_len);
43499f3bedSPekka Enberg }
449f532d00SPekka Enberg 
4543835ac9SSasha Levin static inline ssize_t disk_image__read_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
4670b53f25SSasha Levin {
4743835ac9SSasha Levin 	if (disk->ops->read_sector_iov)
4843835ac9SSasha Levin 		return disk->ops->read_sector_iov(disk, sector, iov, iovcount);
4970b53f25SSasha Levin 
5070b53f25SSasha Levin 	while (iovcount--) {
51f10860caSPekka Enberg 		if (disk->ops->read_sector(disk, sector, iov->iov_base, iov->iov_len) < 0)
52f10860caSPekka Enberg 			return -1;
53f10860caSPekka Enberg 
5470b53f25SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
5570b53f25SSasha Levin 		iov++;
5670b53f25SSasha Levin 	}
5770b53f25SSasha Levin 
5870b53f25SSasha Levin 	return sector << SECTOR_SHIFT;
5970b53f25SSasha Levin }
6070b53f25SSasha Levin 
6143835ac9SSasha Levin static inline ssize_t disk_image__write_sector_iov(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
6270b53f25SSasha Levin {
6343835ac9SSasha Levin 	if (disk->ops->write_sector_iov)
6443835ac9SSasha Levin 		return disk->ops->write_sector_iov(disk, sector, iov, iovcount);
6570b53f25SSasha Levin 
6670b53f25SSasha Levin 	while (iovcount--) {
67f10860caSPekka Enberg 		if (disk->ops->write_sector(disk, sector, iov->iov_base, iov->iov_len) < 0)
68f10860caSPekka Enberg 			return -1;
69f10860caSPekka Enberg 
7070b53f25SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
7170b53f25SSasha Levin 		iov++;
7270b53f25SSasha Levin 	}
7370b53f25SSasha Levin 
7470b53f25SSasha Levin 	return sector << SECTOR_SHIFT;
7570b53f25SSasha Levin }
7670b53f25SSasha Levin 
77*29084a74SPrasad Joshi static inline int disk_image__flush(struct disk_image *disk)
78*29084a74SPrasad Joshi {
79*29084a74SPrasad Joshi 	if (disk->ops->flush)
80*29084a74SPrasad Joshi 		return disk->ops->flush(disk);
81*29084a74SPrasad Joshi 	return fsync(disk->fd);
82*29084a74SPrasad Joshi }
83*29084a74SPrasad Joshi 
849f532d00SPekka Enberg #endif /* KVM__DISK_IMAGE_H */
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