1 #ifndef KVM__DISK_IMAGE_H 2 #define KVM__DISK_IMAGE_H 3 4 #include <stdint.h> 5 #include <stdbool.h> 6 #include <sys/uio.h> 7 8 #define SECTOR_SHIFT 9 9 #define SECTOR_SIZE (1UL << SECTOR_SHIFT) 10 11 struct disk_image; 12 13 struct disk_image_operations { 14 int (*read_sector)(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len); 15 int (*write_sector)(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len); 16 ssize_t (*read_sector_sg)(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount); 17 ssize_t (*write_sector_sg)(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount); 18 void (*close)(struct disk_image *self); 19 }; 20 21 struct disk_image { 22 int fd; 23 uint64_t size; 24 struct disk_image_operations *ops; 25 void *priv; 26 }; 27 28 struct disk_image *disk_image__open(const char *filename, bool readonly); 29 struct disk_image *disk_image__new(int fd, uint64_t size, struct disk_image_operations *ops); 30 struct disk_image *disk_image__new_readonly(int fd, uint64_t size, struct disk_image_operations *ops); 31 void disk_image__close(struct disk_image *self); 32 33 static inline int disk_image__read_sector(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len) 34 { 35 return self->ops->read_sector(self, sector, dst, dst_len); 36 } 37 38 static inline int disk_image__write_sector(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len) 39 { 40 return self->ops->write_sector(self, sector, src, src_len); 41 } 42 43 static inline ssize_t disk_image__read_sector_sg(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount) 44 { 45 if (self->ops->read_sector_sg) 46 return self->ops->read_sector_sg(self, sector, iov, iovcount); 47 48 while (iovcount--) { 49 self->ops->read_sector(self, sector, iov->iov_base, iov->iov_len); 50 sector += iov->iov_len >> SECTOR_SHIFT; 51 iov++; 52 } 53 54 return sector << SECTOR_SHIFT; 55 } 56 57 static inline ssize_t disk_image__write_sector_sg(struct disk_image *self, uint64_t sector, const struct iovec *iov, int iovcount) 58 { 59 if (self->ops->write_sector_sg) 60 return self->ops->write_sector_sg(self, sector, iov, iovcount); 61 62 while (iovcount--) { 63 self->ops->write_sector(self, sector, iov->iov_base, iov->iov_len); 64 sector += iov->iov_len >> SECTOR_SHIFT; 65 iov++; 66 } 67 68 return sector << SECTOR_SHIFT; 69 } 70 71 #endif /* KVM__DISK_IMAGE_H */ 72