Archipelago » qemu

    uint64_t offsets[0];            /* in bytes */

} QEDTable;

/* The L2 cache is a simple write-through cache for L2 structures */

typedef struct CachedL2Table {

    QEDTable *table;

    uint64_t offset;    /* offset=0 indicates an invalidate entry */

    QTAILQ_ENTRY(CachedL2Table) node;

    int ref;

} CachedL2Table;

typedef struct {

    QTAILQ_HEAD(, CachedL2Table) entries;

    unsigned int n_entries;

} L2TableCache;

typedef struct QEDRequest {

    CachedL2Table *l2_table;

} QEDRequest;

typedef struct {

    QEDTable *l1_table;

    L2TableCache l2_cache;          /* l2 table cache */

enum {

    QED_CLUSTER_FOUND,         /* cluster found */

    QED_CLUSTER_L2,            /* cluster missing in L2 */

    QED_CLUSTER_L1,            /* cluster missing in L1 */

};

/**

 * qed_find_cluster() completion callback

 *

 * @opaque:     User data for completion callback

 * @ret:        QED_CLUSTER_FOUND   Success

 *              QED_CLUSTER_L2      Data cluster unallocated in L2

 *              QED_CLUSTER_L1      L2 unallocated in L1

 *              -errno              POSIX error occurred

 * @offset:     Data cluster offset

 * @len:        Contiguous bytes starting from cluster offset

 *

 * This function is invoked when qed_find_cluster() completes.

 *

 * On success ret is QED_CLUSTER_FOUND and offset/len are a contiguous range

 * in the image file.

 *

 * On failure ret is QED_CLUSTER_L2 or QED_CLUSTER_L1 for missing L2 or L1

 * table offset, respectively.  len is number of contiguous unallocated bytes.

 */

typedef void QEDFindClusterFunc(void *opaque, int ret, uint64_t offset, size_t len);

/**

 * Generic callback for chaining async callbacks

 */

typedef struct {

    BlockDriverCompletionFunc *cb;

    void *opaque;

} GenericCB;

void *gencb_alloc(size_t len, BlockDriverCompletionFunc *cb, void *opaque);

void gencb_complete(void *opaque, int ret);

/**

 * L2 cache functions

 */

void qed_init_l2_cache(L2TableCache *l2_cache);

void qed_free_l2_cache(L2TableCache *l2_cache);

CachedL2Table *qed_alloc_l2_cache_entry(L2TableCache *l2_cache);

void qed_unref_l2_cache_entry(CachedL2Table *entry);

CachedL2Table *qed_find_l2_cache_entry(L2TableCache *l2_cache, uint64_t offset);

void qed_commit_l2_cache_entry(L2TableCache *l2_cache, CachedL2Table *l2_table);

/**

 * Table I/O functions

 */

int qed_read_l1_table_sync(BDRVQEDState *s);

void qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n,

                        BlockDriverCompletionFunc *cb, void *opaque);

int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,

                            unsigned int n);

int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request,

                           uint64_t offset);

void qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset,

                       BlockDriverCompletionFunc *cb, void *opaque);

void qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,

                        unsigned int index, unsigned int n, bool flush,

                        BlockDriverCompletionFunc *cb, void *opaque);

int qed_write_l2_table_sync(BDRVQEDState *s, QEDRequest *request,

                            unsigned int index, unsigned int n, bool flush);

/**

 * Cluster functions

 */

void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos,

                      size_t len, QEDFindClusterFunc *cb, void *opaque);

/**

 * Consistency check

 */

int qed_check(BDRVQEDState *s, BdrvCheckResult *result, bool fix);

QEDTable *qed_alloc_table(BDRVQEDState *s);

static inline uint64_t qed_offset_into_cluster(BDRVQEDState *s, uint64_t offset)

{

    return offset & (s->header.cluster_size - 1);

}

static inline unsigned int qed_bytes_to_clusters(BDRVQEDState *s, size_t bytes)

{

    return qed_start_of_cluster(s, bytes + (s->header.cluster_size - 1)) /

           (s->header.cluster_size - 1);

}

static inline unsigned int qed_l1_index(BDRVQEDState *s, uint64_t pos)

{

    return pos >> s->l1_shift;

}

static inline unsigned int qed_l2_index(BDRVQEDState *s, uint64_t pos)

{

    return (pos >> s->l2_shift) & s->l2_mask;

}