/* The cluster reads as all zeros */
#define QCOW_OFLAG_ZERO (1ULL << 0)
+#define QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER 32
+
+/* The subcluster X [0..31] is allocated */
+#define QCOW_OFLAG_SUB_ALLOC(X) (1ULL << (X))
+/* The subcluster X [0..31] reads as zeroes */
+#define QCOW_OFLAG_SUB_ZERO(X) (QCOW_OFLAG_SUB_ALLOC(X) << 32)
+/* Subclusters [X, Y) (0 <= X <= Y <= 32) are allocated */
+#define QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) \
+ (QCOW_OFLAG_SUB_ALLOC(Y) - QCOW_OFLAG_SUB_ALLOC(X))
+/* Subclusters [X, Y) (0 <= X <= Y <= 32) read as zeroes */
+#define QCOW_OFLAG_SUB_ZERO_RANGE(X, Y) \
+ (QCOW_OFLAG_SUB_ALLOC_RANGE(X, Y) << 32)
+/* L2 entry bitmap with all allocation bits set */
+#define QCOW_L2_BITMAP_ALL_ALLOC (QCOW_OFLAG_SUB_ALLOC_RANGE(0, 32))
+/* L2 entry bitmap with all "read as zeroes" bits set */
+#define QCOW_L2_BITMAP_ALL_ZEROES (QCOW_OFLAG_SUB_ZERO_RANGE(0, 32))
+
+/* Size of normal and extended L2 entries */
+#define L2E_SIZE_NORMAL (sizeof(uint64_t))
+#define L2E_SIZE_EXTENDED (sizeof(uint64_t) * 2)
+
+/* Size of L1 table entries */
+#define L1E_SIZE (sizeof(uint64_t))
+
+/* Size of reftable entries */
+#define REFTABLE_ENTRY_SIZE (sizeof(uint64_t))
+
#define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21
/* Defined in the qcow2 spec (compressed cluster descriptor) */
#define QCOW2_COMPRESSED_SECTOR_SIZE 512U
-#define QCOW2_COMPRESSED_SECTOR_MASK (~(QCOW2_COMPRESSED_SECTOR_SIZE - 1ULL))
/* Must be at least 2 to cover COW */
#define MIN_L2_CACHE_SIZE 2 /* cache entries */
uint32_t refcount_order;
uint32_t header_length;
+
+ /* Additional fields */
+ uint8_t compression_type;
+
+ /* header must be a multiple of 8 */
+ uint8_t padding[7];
} QEMU_PACKED QCowHeader;
+QEMU_BUILD_BUG_ON(!QEMU_IS_ALIGNED(sizeof(QCowHeader), 8));
+
typedef struct QEMU_PACKED QCowSnapshotHeader {
/* header is 8 byte aligned */
uint64_t l1_table_offset;
typedef struct QEMU_PACKED QCowSnapshotExtraData {
uint64_t vm_state_size_large;
uint64_t disk_size;
+ uint64_t icount;
} QCowSnapshotExtraData;
uint32_t date_sec;
uint32_t date_nsec;
uint64_t vm_clock_nsec;
+ /* icount value for the moment when snapshot was taken */
+ uint64_t icount;
/* Size of all extra data, including QCowSnapshotExtraData if available */
uint32_t extra_data_size;
/* Data beyond QCowSnapshotExtraData, if any */
QCOW2_INCOMPAT_DIRTY_BITNR = 0,
QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
QCOW2_INCOMPAT_DATA_FILE_BITNR = 2,
+ QCOW2_INCOMPAT_COMPRESSION_BITNR = 3,
+ QCOW2_INCOMPAT_EXTL2_BITNR = 4,
QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
QCOW2_INCOMPAT_DATA_FILE = 1 << QCOW2_INCOMPAT_DATA_FILE_BITNR,
+ QCOW2_INCOMPAT_COMPRESSION = 1 << QCOW2_INCOMPAT_COMPRESSION_BITNR,
+ QCOW2_INCOMPAT_EXTL2 = 1 << QCOW2_INCOMPAT_EXTL2_BITNR,
QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY
| QCOW2_INCOMPAT_CORRUPT
- | QCOW2_INCOMPAT_DATA_FILE,
+ | QCOW2_INCOMPAT_DATA_FILE
+ | QCOW2_INCOMPAT_COMPRESSION
+ | QCOW2_INCOMPAT_EXTL2,
};
/* Compatible feature bits */
int cluster_bits;
int cluster_size;
int l2_slice_size;
+ int subcluster_bits;
+ int subcluster_size;
+ int subclusters_per_cluster;
int l2_bits;
int l2_size;
int l1_size;
uint64_t l1_table_offset;
uint64_t *l1_table;
- Qcow2Cache* l2_table_cache;
- Qcow2Cache* refcount_block_cache;
+ Qcow2Cache *l2_table_cache;
+ Qcow2Cache *refcount_block_cache;
QEMUTimer *cache_clean_timer;
unsigned cache_clean_interval;
uint64_t autoclear_features;
size_t unknown_header_fields_size;
- void* unknown_header_fields;
+ void *unknown_header_fields;
QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
bool cache_discards;
bool metadata_preallocation_checked;
bool metadata_preallocation;
+ /*
+ * Compression type used for the image. Default: 0 - ZLIB
+ * The image compression type is set on image creation.
+ * For now, the only way to change the compression type
+ * is to convert the image with the desired compression type set.
+ */
+ Qcow2CompressionType compression_type;
} BDRVQcow2State;
typedef struct Qcow2COWRegion {
/**
* Describes an in-flight (part of a) write request that writes to clusters
- * that are not referenced in their L2 table yet.
+ * that need to have their L2 table entries updated (because they are
+ * newly allocated or need changes in their L2 bitmaps)
*/
typedef struct QCowL2Meta
{
- /** Guest offset of the first newly allocated cluster */
+ /** Guest offset of the first updated cluster */
uint64_t offset;
- /** Host offset of the first newly allocated cluster */
+ /** Host offset of the first updated cluster */
uint64_t alloc_offset;
- /** Number of newly allocated clusters */
+ /** Number of updated clusters */
int nb_clusters;
/** Do not free the old clusters */
CoQueue dependent_requests;
/**
- * The COW Region between the start of the first allocated cluster and the
- * area the guest actually writes to.
+ * The COW Region immediately before the area the guest actually
+ * writes to. This (part of the) write request starts at
+ * cow_start.offset + cow_start.nb_bytes.
*/
Qcow2COWRegion cow_start;
/**
- * The COW Region between the area the guest actually writes to and the
- * end of the last allocated cluster.
+ * The COW Region immediately after the area the guest actually
+ * writes to. This (part of the) write request ends at cow_end.offset
+ * (which must always be set even when cow_end.nb_bytes is 0).
*/
Qcow2COWRegion cow_end;
*/
bool skip_cow;
+ /**
+ * Indicates that this is not a normal write request but a preallocation.
+ * If the image has extended L2 entries this means that no new individual
+ * subclusters will be marked as allocated in the L2 bitmap (but any
+ * existing contents of that bitmap will be kept).
+ */
+ bool prealloc;
+
/**
* The I/O vector with the data from the actual guest write request.
* If non-NULL, this is meant to be merged together with the data
QLIST_ENTRY(QCowL2Meta) next_in_flight;
} QCowL2Meta;
+/*
+ * In images with standard L2 entries all clusters are treated as if
+ * they had one subcluster so QCow2ClusterType and QCow2SubclusterType
+ * can be mapped to each other and have the exact same meaning
+ * (QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC cannot happen in these images).
+ *
+ * In images with extended L2 entries QCow2ClusterType refers to the
+ * complete cluster and QCow2SubclusterType to each of the individual
+ * subclusters, so there are several possible combinations:
+ *
+ * |--------------+---------------------------|
+ * | Cluster type | Possible subcluster types |
+ * |--------------+---------------------------|
+ * | UNALLOCATED | UNALLOCATED_PLAIN |
+ * | | ZERO_PLAIN |
+ * |--------------+---------------------------|
+ * | NORMAL | UNALLOCATED_ALLOC |
+ * | | ZERO_ALLOC |
+ * | | NORMAL |
+ * |--------------+---------------------------|
+ * | COMPRESSED | COMPRESSED |
+ * |--------------+---------------------------|
+ *
+ * QCOW2_SUBCLUSTER_INVALID means that the L2 entry is incorrect and
+ * the image should be marked corrupt.
+ */
+
typedef enum QCow2ClusterType {
QCOW2_CLUSTER_UNALLOCATED,
QCOW2_CLUSTER_ZERO_PLAIN,
QCOW2_CLUSTER_COMPRESSED,
} QCow2ClusterType;
+typedef enum QCow2SubclusterType {
+ QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN,
+ QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC,
+ QCOW2_SUBCLUSTER_ZERO_PLAIN,
+ QCOW2_SUBCLUSTER_ZERO_ALLOC,
+ QCOW2_SUBCLUSTER_NORMAL,
+ QCOW2_SUBCLUSTER_COMPRESSED,
+ QCOW2_SUBCLUSTER_INVALID,
+} QCow2SubclusterType;
+
typedef enum QCow2MetadataOverlap {
QCOW2_OL_MAIN_HEADER_BITNR = 0,
QCOW2_OL_ACTIVE_L1_BITNR = 1,
(QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)
#define L1E_OFFSET_MASK 0x00fffffffffffe00ULL
+#define L1E_RESERVED_MASK 0x7f000000000001ffULL
#define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
-#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
+#define L2E_STD_RESERVED_MASK 0x3f000000000001feULL
#define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
+#define REFT_RESERVED_MASK 0x1ffULL
#define INV_OFFSET (-1ULL)
+static inline bool has_subclusters(BDRVQcow2State *s)
+{
+ return s->incompatible_features & QCOW2_INCOMPAT_EXTL2;
+}
+
+static inline size_t l2_entry_size(BDRVQcow2State *s)
+{
+ return has_subclusters(s) ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
+}
+
+static inline uint64_t get_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
+ int idx)
+{
+ idx *= l2_entry_size(s) / sizeof(uint64_t);
+ return be64_to_cpu(l2_slice[idx]);
+}
+
+static inline uint64_t get_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
+ int idx)
+{
+ if (has_subclusters(s)) {
+ idx *= l2_entry_size(s) / sizeof(uint64_t);
+ return be64_to_cpu(l2_slice[idx + 1]);
+ } else {
+ return 0; /* For convenience only; this value has no meaning. */
+ }
+}
+
+static inline void set_l2_entry(BDRVQcow2State *s, uint64_t *l2_slice,
+ int idx, uint64_t entry)
+{
+ idx *= l2_entry_size(s) / sizeof(uint64_t);
+ l2_slice[idx] = cpu_to_be64(entry);
+}
+
+static inline void set_l2_bitmap(BDRVQcow2State *s, uint64_t *l2_slice,
+ int idx, uint64_t bitmap)
+{
+ assert(has_subclusters(s));
+ idx *= l2_entry_size(s) / sizeof(uint64_t);
+ l2_slice[idx + 1] = cpu_to_be64(bitmap);
+}
+
static inline bool has_data_file(BlockDriverState *bs)
{
BDRVQcow2State *s = bs->opaque;
return offset & (s->cluster_size - 1);
}
+static inline int64_t offset_into_subcluster(BDRVQcow2State *s, int64_t offset)
+{
+ return offset & (s->subcluster_size - 1);
+}
+
static inline uint64_t size_to_clusters(BDRVQcow2State *s, uint64_t size)
{
return (size + (s->cluster_size - 1)) >> s->cluster_bits;
}
+static inline uint64_t size_to_subclusters(BDRVQcow2State *s, uint64_t size)
+{
+ return (size + (s->subcluster_size - 1)) >> s->subcluster_bits;
+}
+
static inline int64_t size_to_l1(BDRVQcow2State *s, int64_t size)
{
int shift = s->cluster_bits + s->l2_bits;
return (offset >> s->cluster_bits) & (s->l2_slice_size - 1);
}
+static inline int offset_to_sc_index(BDRVQcow2State *s, int64_t offset)
+{
+ return (offset >> s->subcluster_bits) & (s->subclusters_per_cluster - 1);
+}
+
static inline int64_t qcow2_vm_state_offset(BDRVQcow2State *s)
{
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
uint64_t l2_entry)
{
+ BDRVQcow2State *s = bs->opaque;
+
if (l2_entry & QCOW_OFLAG_COMPRESSED) {
return QCOW2_CLUSTER_COMPRESSED;
- } else if (l2_entry & QCOW_OFLAG_ZERO) {
+ } else if ((l2_entry & QCOW_OFLAG_ZERO) && !has_subclusters(s)) {
if (l2_entry & L2E_OFFSET_MASK) {
return QCOW2_CLUSTER_ZERO_ALLOC;
}
}
}
+/*
+ * In an image without subsclusters @l2_bitmap is ignored and
+ * @sc_index must be 0.
+ * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
+ * (this checks the whole entry and bitmap, not only the bits related
+ * to subcluster @sc_index).
+ */
+static inline
+QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
+ uint64_t l2_entry,
+ uint64_t l2_bitmap,
+ unsigned sc_index)
+{
+ BDRVQcow2State *s = bs->opaque;
+ QCow2ClusterType type = qcow2_get_cluster_type(bs, l2_entry);
+ assert(sc_index < s->subclusters_per_cluster);
+
+ if (has_subclusters(s)) {
+ switch (type) {
+ case QCOW2_CLUSTER_COMPRESSED:
+ return QCOW2_SUBCLUSTER_COMPRESSED;
+ case QCOW2_CLUSTER_NORMAL:
+ if ((l2_bitmap >> 32) & l2_bitmap) {
+ return QCOW2_SUBCLUSTER_INVALID;
+ } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
+ return QCOW2_SUBCLUSTER_ZERO_ALLOC;
+ } else if (l2_bitmap & QCOW_OFLAG_SUB_ALLOC(sc_index)) {
+ return QCOW2_SUBCLUSTER_NORMAL;
+ } else {
+ return QCOW2_SUBCLUSTER_UNALLOCATED_ALLOC;
+ }
+ case QCOW2_CLUSTER_UNALLOCATED:
+ if (l2_bitmap & QCOW_L2_BITMAP_ALL_ALLOC) {
+ return QCOW2_SUBCLUSTER_INVALID;
+ } else if (l2_bitmap & QCOW_OFLAG_SUB_ZERO(sc_index)) {
+ return QCOW2_SUBCLUSTER_ZERO_PLAIN;
+ } else {
+ return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
+ }
+ default:
+ g_assert_not_reached();
+ }
+ } else {
+ switch (type) {
+ case QCOW2_CLUSTER_COMPRESSED:
+ return QCOW2_SUBCLUSTER_COMPRESSED;
+ case QCOW2_CLUSTER_ZERO_PLAIN:
+ return QCOW2_SUBCLUSTER_ZERO_PLAIN;
+ case QCOW2_CLUSTER_ZERO_ALLOC:
+ return QCOW2_SUBCLUSTER_ZERO_ALLOC;
+ case QCOW2_CLUSTER_NORMAL:
+ return QCOW2_SUBCLUSTER_NORMAL;
+ case QCOW2_CLUSTER_UNALLOCATED:
+ return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
+ default:
+ g_assert_not_reached();
+ }
+ }
+}
+
+static inline bool qcow2_cluster_is_allocated(QCow2ClusterType type)
+{
+ return (type == QCOW2_CLUSTER_COMPRESSED || type == QCOW2_CLUSTER_NORMAL ||
+ type == QCOW2_CLUSTER_ZERO_ALLOC);
+}
+
/* Check whether refcounts are eager or lazy */
static inline bool qcow2_need_accurate_refcounts(BDRVQcow2State *s)
{
void qcow2_free_clusters(BlockDriverState *bs,
int64_t offset, int64_t size,
enum qcow2_discard_type type);
-void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
- int nb_clusters, enum qcow2_discard_type type);
+void qcow2_free_any_cluster(BlockDriverState *bs, uint64_t l2_entry,
+ enum qcow2_discard_type type);
int qcow2_update_snapshot_refcount(BlockDriverState *bs,
int64_t l1_table_offset, int l1_size, int addend);
int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num,
uint8_t *buf, int nb_sectors, bool enc, Error **errp);
-int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
- unsigned int *bytes, uint64_t *cluster_offset);
-int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
- unsigned int *bytes, uint64_t *host_offset,
- QCowL2Meta **m);
+int qcow2_get_host_offset(BlockDriverState *bs, uint64_t offset,
+ unsigned int *bytes, uint64_t *host_offset,
+ QCow2SubclusterType *subcluster_type);
+int qcow2_alloc_host_offset(BlockDriverState *bs, uint64_t offset,
+ unsigned int *bytes, uint64_t *host_offset,
+ QCowL2Meta **m);
int qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
uint64_t offset,
int compressed_size,
uint64_t *host_offset);
+void qcow2_parse_compressed_l2_entry(BlockDriverState *bs, uint64_t l2_entry,
+ uint64_t *coffset, int *csize);
int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
void qcow2_alloc_cluster_abort(BlockDriverState *bs, QCowL2Meta *m);
int qcow2_cluster_discard(BlockDriverState *bs, uint64_t offset,
uint64_t bytes, enum qcow2_discard_type type,
bool full_discard);
-int qcow2_cluster_zeroize(BlockDriverState *bs, uint64_t offset,
- uint64_t bytes, int flags);
+int qcow2_subcluster_zeroize(BlockDriverState *bs, uint64_t offset,
+ uint64_t bytes, int flags);
int qcow2_expand_zero_clusters(BlockDriverState *bs,
BlockDriverAmendStatusCB *status_cb,
int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
void **refcount_table,
int64_t *refcount_table_size);
-bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
-Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
- Error **errp);
+bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, bool *header_updated,
+ Error **errp);
+bool qcow2_get_bitmap_info_list(BlockDriverState *bs,
+ Qcow2BitmapInfoList **info_list, Error **errp);
int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
int qcow2_truncate_bitmaps_check(BlockDriverState *bs, Error **errp);
-void qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
+bool qcow2_store_persistent_dirty_bitmaps(BlockDriverState *bs,
bool release_stored, Error **errp);
int qcow2_reopen_bitmaps_ro(BlockDriverState *bs, Error **errp);
bool qcow2_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
int qcow2_co_remove_persistent_dirty_bitmap(BlockDriverState *bs,
const char *name,
Error **errp);
+bool qcow2_supports_persistent_dirty_bitmap(BlockDriverState *bs);
+uint64_t qcow2_get_persistent_dirty_bitmap_size(BlockDriverState *bs,
+ uint32_t cluster_size);
ssize_t coroutine_fn
qcow2_co_compress(BlockDriverState *bs, void *dest, size_t dest_size,
projects / mirror_qemu.git / blobdiff