xref: /kvmtool/include/kvm/disk-image.h (revision 70b53f25590d3d99eaa51f3600a67482e155e0e2)
19f532d00SPekka Enberg #ifndef KVM__DISK_IMAGE_H
29f532d00SPekka Enberg #define KVM__DISK_IMAGE_H
39f532d00SPekka Enberg 
49f532d00SPekka Enberg #include <stdint.h>
59ac38fe1SSasha Levin #include <stdbool.h>
6*70b53f25SSasha 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 {
14499f3bedSPekka Enberg 	int (*read_sector)(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len);
15499f3bedSPekka Enberg 	int (*write_sector)(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len);
16*70b53f25SSasha Levin 	ssize_t (*read_sector_sg)(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount);
17*70b53f25SSasha Levin 	ssize_t (*write_sector_sg)(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount);
18499f3bedSPekka Enberg 	void (*close)(struct disk_image *self);
19499f3bedSPekka Enberg };
20499f3bedSPekka Enberg 
219f532d00SPekka Enberg struct disk_image {
229f532d00SPekka Enberg 	int				fd;
239f532d00SPekka Enberg 	uint64_t			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);
29f4ff38dfSPrasad Joshi struct disk_image *disk_image__new(int fd, uint64_t size, struct disk_image_operations *ops);
30f4ff38dfSPrasad Joshi struct disk_image *disk_image__new_readonly(int fd, uint64_t size, struct disk_image_operations *ops);
319f532d00SPekka Enberg void disk_image__close(struct disk_image *self);
32499f3bedSPekka Enberg 
33499f3bedSPekka Enberg static inline int disk_image__read_sector(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len)
34499f3bedSPekka Enberg {
35499f3bedSPekka Enberg 	return self->ops->read_sector(self, sector, dst, dst_len);
36499f3bedSPekka Enberg }
37499f3bedSPekka Enberg 
38499f3bedSPekka Enberg static inline int disk_image__write_sector(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len)
39499f3bedSPekka Enberg {
40499f3bedSPekka Enberg 	return self->ops->write_sector(self, sector, src, src_len);
41499f3bedSPekka Enberg }
429f532d00SPekka Enberg 
43*70b53f25SSasha Levin static inline ssize_t disk_image__read_sector_sg(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount)
44*70b53f25SSasha Levin {
45*70b53f25SSasha Levin 	if (self->ops->read_sector_sg)
46*70b53f25SSasha Levin 		return self->ops->read_sector_sg(self, sector, iov, iovcount);
47*70b53f25SSasha Levin 
48*70b53f25SSasha Levin 	while (iovcount--) {
49*70b53f25SSasha Levin 		self->ops->read_sector(self, sector, iov->iov_base, iov->iov_len);
50*70b53f25SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
51*70b53f25SSasha Levin 		iov++;
52*70b53f25SSasha Levin 	}
53*70b53f25SSasha Levin 
54*70b53f25SSasha Levin 	return sector << SECTOR_SHIFT;
55*70b53f25SSasha Levin }
56*70b53f25SSasha Levin 
57*70b53f25SSasha Levin static inline ssize_t disk_image__write_sector_sg(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount)
58*70b53f25SSasha Levin {
59*70b53f25SSasha Levin 	if (self->ops->write_sector_sg)
60*70b53f25SSasha Levin 		return self->ops->write_sector_sg(self, sector, iov, iovcount);
61*70b53f25SSasha Levin 
62*70b53f25SSasha Levin 	while (iovcount--) {
63*70b53f25SSasha Levin 		self->ops->write_sector(self, sector, iov->iov_base, iov->iov_len);
64*70b53f25SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
65*70b53f25SSasha Levin 		iov++;
66*70b53f25SSasha Levin 	}
67*70b53f25SSasha Levin 
68*70b53f25SSasha Levin 	return sector << SECTOR_SHIFT;
69*70b53f25SSasha Levin }
70*70b53f25SSasha Levin 
719f532d00SPekka Enberg #endif /* KVM__DISK_IMAGE_H */
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