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Diffstat (limited to 'block/qcow2.h')
| -rw-r--r-- | block/qcow2.h | 1017 |
1 files changed, 1017 insertions, 0 deletions
diff --git a/block/qcow2.h b/block/qcow2.h new file mode 100644 index 000000000..fd48a89d4 --- /dev/null +++ b/block/qcow2.h @@ -0,0 +1,1017 @@ +/* + * Block driver for the QCOW version 2 format + * + * Copyright (c) 2004-2006 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#ifndef BLOCK_QCOW2_H +#define BLOCK_QCOW2_H + +#include "crypto/block.h" +#include "qemu/coroutine.h" +#include "qemu/units.h" +#include "block/block_int.h" + +//#define DEBUG_ALLOC +//#define DEBUG_ALLOC2 +//#define DEBUG_EXT + +#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) + +#define QCOW_CRYPT_NONE 0 +#define QCOW_CRYPT_AES 1 +#define QCOW_CRYPT_LUKS 2 + +#define QCOW_MAX_CRYPT_CLUSTERS 32 +#define QCOW_MAX_SNAPSHOTS 65536 + +/* Field widths in qcow2 mean normal cluster offsets cannot reach + * 64PB; depending on cluster size, compressed clusters can have a + * smaller limit (64PB for up to 16k clusters, then ramps down to + * 512TB for 2M clusters). */ +#define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1) + +/* 8 MB refcount table is enough for 2 PB images at 64k cluster size + * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ +#define QCOW_MAX_REFTABLE_SIZE (8 * MiB) + +/* 32 MB L1 table is enough for 2 PB images at 64k cluster size + * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ +#define QCOW_MAX_L1_SIZE (32 * MiB) + +/* Allow for an average of 1k per snapshot table entry, should be plenty of + * space for snapshot names and IDs */ +#define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) + +/* Maximum amount of extra data per snapshot table entry to accept */ +#define QCOW_MAX_SNAPSHOT_EXTRA_DATA 1024 + +/* Bitmap header extension constraints */ +#define QCOW2_MAX_BITMAPS 65535 +#define QCOW2_MAX_BITMAP_DIRECTORY_SIZE (1024 * QCOW2_MAX_BITMAPS) + +/* Maximum of parallel sub-request per guest request */ +#define QCOW2_MAX_WORKERS 8 + +/* indicate that the refcount of the referenced cluster is exactly one. */ +#define QCOW_OFLAG_COPIED (1ULL << 63) +/* indicate that the cluster is compressed (they never have the copied flag) */ +#define QCOW_OFLAG_COMPRESSED (1ULL << 62) +/* 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 + +/* Must be at least 2 to cover COW */ +#define MIN_L2_CACHE_SIZE 2 /* cache entries */ + +/* Must be at least 4 to cover all cases of refcount table growth */ +#define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */ + +#ifdef CONFIG_LINUX +#define DEFAULT_L2_CACHE_MAX_SIZE (32 * MiB) +#define DEFAULT_CACHE_CLEAN_INTERVAL 600 /* seconds */ +#else +#define DEFAULT_L2_CACHE_MAX_SIZE (8 * MiB) +/* Cache clean interval is currently available only on Linux, so must be 0 */ +#define DEFAULT_CACHE_CLEAN_INTERVAL 0 +#endif + +#define DEFAULT_CLUSTER_SIZE 65536 + +#define QCOW2_OPT_DATA_FILE "data-file" +#define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts" +#define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request" +#define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot" +#define QCOW2_OPT_DISCARD_OTHER "pass-discard-other" +#define QCOW2_OPT_OVERLAP "overlap-check" +#define QCOW2_OPT_OVERLAP_TEMPLATE "overlap-check.template" +#define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header" +#define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1" +#define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2" +#define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table" +#define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block" +#define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table" +#define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1" +#define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2" +#define QCOW2_OPT_OVERLAP_BITMAP_DIRECTORY "overlap-check.bitmap-directory" +#define QCOW2_OPT_CACHE_SIZE "cache-size" +#define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size" +#define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size" +#define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size" +#define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval" + +typedef struct QCowHeader { + uint32_t magic; + uint32_t version; + uint64_t backing_file_offset; + uint32_t backing_file_size; + uint32_t cluster_bits; + uint64_t size; /* in bytes */ + uint32_t crypt_method; + uint32_t l1_size; /* XXX: save number of clusters instead ? */ + uint64_t l1_table_offset; + uint64_t refcount_table_offset; + uint32_t refcount_table_clusters; + uint32_t nb_snapshots; + uint64_t snapshots_offset; + + /* The following fields are only valid for version >= 3 */ + uint64_t incompatible_features; + uint64_t compatible_features; + uint64_t autoclear_features; + + 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; + + uint32_t l1_size; + uint16_t id_str_size; + uint16_t name_size; + + uint32_t date_sec; + uint32_t date_nsec; + + uint64_t vm_clock_nsec; + + uint32_t vm_state_size; + uint32_t extra_data_size; /* for extension */ + /* extra data follows */ + /* id_str follows */ + /* name follows */ +} QCowSnapshotHeader; + +typedef struct QEMU_PACKED QCowSnapshotExtraData { + uint64_t vm_state_size_large; + uint64_t disk_size; + uint64_t icount; +} QCowSnapshotExtraData; + + +typedef struct QCowSnapshot { + uint64_t l1_table_offset; + uint32_t l1_size; + char *id_str; + char *name; + uint64_t disk_size; + uint64_t vm_state_size; + 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 */ + void *unknown_extra_data; +} QCowSnapshot; + +struct Qcow2Cache; +typedef struct Qcow2Cache Qcow2Cache; + +typedef struct Qcow2CryptoHeaderExtension { + uint64_t offset; + uint64_t length; +} QEMU_PACKED Qcow2CryptoHeaderExtension; + +typedef struct Qcow2UnknownHeaderExtension { + uint32_t magic; + uint32_t len; + QLIST_ENTRY(Qcow2UnknownHeaderExtension) next; + uint8_t data[]; +} Qcow2UnknownHeaderExtension; + +enum { + QCOW2_FEAT_TYPE_INCOMPATIBLE = 0, + QCOW2_FEAT_TYPE_COMPATIBLE = 1, + QCOW2_FEAT_TYPE_AUTOCLEAR = 2, +}; + +/* Incompatible feature bits */ +enum { + 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_COMPRESSION + | QCOW2_INCOMPAT_EXTL2, +}; + +/* Compatible feature bits */ +enum { + QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0, + QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR, + + QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS, +}; + +/* Autoclear feature bits */ +enum { + QCOW2_AUTOCLEAR_BITMAPS_BITNR = 0, + QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR = 1, + QCOW2_AUTOCLEAR_BITMAPS = 1 << QCOW2_AUTOCLEAR_BITMAPS_BITNR, + QCOW2_AUTOCLEAR_DATA_FILE_RAW = 1 << QCOW2_AUTOCLEAR_DATA_FILE_RAW_BITNR, + + QCOW2_AUTOCLEAR_MASK = QCOW2_AUTOCLEAR_BITMAPS + | QCOW2_AUTOCLEAR_DATA_FILE_RAW, +}; + +enum qcow2_discard_type { + QCOW2_DISCARD_NEVER = 0, + QCOW2_DISCARD_ALWAYS, + QCOW2_DISCARD_REQUEST, + QCOW2_DISCARD_SNAPSHOT, + QCOW2_DISCARD_OTHER, + QCOW2_DISCARD_MAX +}; + +typedef struct Qcow2Feature { + uint8_t type; + uint8_t bit; + char name[46]; +} QEMU_PACKED Qcow2Feature; + +typedef struct Qcow2DiscardRegion { + BlockDriverState *bs; + uint64_t offset; + uint64_t bytes; + QTAILQ_ENTRY(Qcow2DiscardRegion) next; +} Qcow2DiscardRegion; + +typedef uint64_t Qcow2GetRefcountFunc(const void *refcount_array, + uint64_t index); +typedef void Qcow2SetRefcountFunc(void *refcount_array, + uint64_t index, uint64_t value); + +typedef struct Qcow2BitmapHeaderExt { + uint32_t nb_bitmaps; + uint32_t reserved32; + uint64_t bitmap_directory_size; + uint64_t bitmap_directory_offset; +} QEMU_PACKED Qcow2BitmapHeaderExt; + +#define QCOW2_MAX_THREADS 4 + +typedef struct BDRVQcow2State { + 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; + int l1_vm_state_index; + int refcount_block_bits; + int refcount_block_size; + int csize_shift; + int csize_mask; + uint64_t cluster_offset_mask; + uint64_t l1_table_offset; + uint64_t *l1_table; + + Qcow2Cache *l2_table_cache; + Qcow2Cache *refcount_block_cache; + QEMUTimer *cache_clean_timer; + unsigned cache_clean_interval; + + QLIST_HEAD(, QCowL2Meta) cluster_allocs; + + uint64_t *refcount_table; + uint64_t refcount_table_offset; + uint32_t refcount_table_size; + uint32_t max_refcount_table_index; /* Last used entry in refcount_table */ + uint64_t free_cluster_index; + uint64_t free_byte_offset; + + CoMutex lock; + + Qcow2CryptoHeaderExtension crypto_header; /* QCow2 header extension */ + QCryptoBlockOpenOptions *crypto_opts; /* Disk encryption runtime options */ + QCryptoBlock *crypto; /* Disk encryption format driver */ + bool crypt_physical_offset; /* Whether to use virtual or physical offset + for encryption initialization vector tweak */ + uint32_t crypt_method_header; + uint64_t snapshots_offset; + int snapshots_size; + unsigned int nb_snapshots; + QCowSnapshot *snapshots; + + uint32_t nb_bitmaps; + uint64_t bitmap_directory_size; + uint64_t bitmap_directory_offset; + + int flags; + int qcow_version; + bool use_lazy_refcounts; + int refcount_order; + int refcount_bits; + uint64_t refcount_max; + + Qcow2GetRefcountFunc *get_refcount; + Qcow2SetRefcountFunc *set_refcount; + + bool discard_passthrough[QCOW2_DISCARD_MAX]; + + int overlap_check; /* bitmask of Qcow2MetadataOverlap values */ + bool signaled_corruption; + + uint64_t incompatible_features; + uint64_t compatible_features; + uint64_t autoclear_features; + + size_t unknown_header_fields_size; + void *unknown_header_fields; + QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; + QTAILQ_HEAD (, Qcow2DiscardRegion) discards; + bool cache_discards; + + /* Backing file path and format as stored in the image (this is not the + * effective path/format, which may be the result of a runtime option + * override) */ + char *image_backing_file; + char *image_backing_format; + char *image_data_file; + + CoQueue thread_task_queue; + int nb_threads; + + BdrvChild *data_file; + + 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 { + /** + * Offset of the COW region in bytes from the start of the first cluster + * touched by the request. + */ + unsigned offset; + + /** Number of bytes to copy */ + unsigned nb_bytes; +} Qcow2COWRegion; + +/** + * Describes an in-flight (part of a) write request that writes to clusters + * 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 updated cluster */ + uint64_t offset; + + /** Host offset of the first updated cluster */ + uint64_t alloc_offset; + + /** Number of updated clusters */ + int nb_clusters; + + /** Do not free the old clusters */ + bool keep_old_clusters; + + /** + * Requests that overlap with this allocation and wait to be restarted + * when the allocating request has completed. + */ + CoQueue dependent_requests; + + /** + * 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 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; + + /* + * Indicates that COW regions are already handled and do not require + * any more processing. + */ + 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 + * from @cow_start and @cow_end into one single write operation. + */ + QEMUIOVector *data_qiov; + size_t data_qiov_offset; + + /** Pointer to next L2Meta of the same write request */ + struct QCowL2Meta *next; + + 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_ZERO_ALLOC, + QCOW2_CLUSTER_NORMAL, + 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_ACTIVE_L2_BITNR = 2, + QCOW2_OL_REFCOUNT_TABLE_BITNR = 3, + QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4, + QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5, + QCOW2_OL_INACTIVE_L1_BITNR = 6, + QCOW2_OL_INACTIVE_L2_BITNR = 7, + QCOW2_OL_BITMAP_DIRECTORY_BITNR = 8, + + QCOW2_OL_MAX_BITNR = 9, + + QCOW2_OL_NONE = 0, + QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR), + QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR), + QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR), + QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR), + QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR), + QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR), + QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR), + /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv + * reads. */ + QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR), + QCOW2_OL_BITMAP_DIRECTORY = (1 << QCOW2_OL_BITMAP_DIRECTORY_BITNR), +} QCow2MetadataOverlap; + +/* Perform all overlap checks which can be done in constant time */ +#define QCOW2_OL_CONSTANT \ + (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \ + QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_BITMAP_DIRECTORY) + +/* Perform all overlap checks which don't require disk access */ +#define QCOW2_OL_CACHED \ + (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \ + QCOW2_OL_INACTIVE_L1) + +/* Perform all overlap checks */ +#define QCOW2_OL_ALL \ + (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2) + +#define L1E_OFFSET_MASK 0x00fffffffffffe00ULL +#define L1E_RESERVED_MASK 0x7f000000000001ffULL +#define L2E_OFFSET_MASK 0x00fffffffffffe00ULL +#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 (s->data_file != bs->file); +} + +static inline bool data_file_is_raw(BlockDriverState *bs) +{ + BDRVQcow2State *s = bs->opaque; + return !!(s->autoclear_features & QCOW2_AUTOCLEAR_DATA_FILE_RAW); +} + +static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset) +{ + return offset & ~(s->cluster_size - 1); +} + +static inline int64_t offset_into_cluster(BDRVQcow2State *s, int64_t offset) +{ + 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 (size + (1ULL << shift) - 1) >> shift; +} + +static inline int offset_to_l1_index(BDRVQcow2State *s, uint64_t offset) +{ + return offset >> (s->l2_bits + s->cluster_bits); +} + +static inline int offset_to_l2_index(BDRVQcow2State *s, int64_t offset) +{ + return (offset >> s->cluster_bits) & (s->l2_size - 1); +} + +static inline int offset_to_l2_slice_index(BDRVQcow2State *s, int64_t offset) +{ + 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) && !has_subclusters(s)) { + if (l2_entry & L2E_OFFSET_MASK) { + return QCOW2_CLUSTER_ZERO_ALLOC; + } + return QCOW2_CLUSTER_ZERO_PLAIN; + } else if (!(l2_entry & L2E_OFFSET_MASK)) { + /* Offset 0 generally means unallocated, but it is ambiguous with + * external data files because 0 is a valid offset there. However, all + * clusters in external data files always have refcount 1, so we can + * rely on QCOW_OFLAG_COPIED to disambiguate. */ + if (has_data_file(bs) && (l2_entry & QCOW_OFLAG_COPIED)) { + return QCOW2_CLUSTER_NORMAL; + } else { + return QCOW2_CLUSTER_UNALLOCATED; + } + } else { + return QCOW2_CLUSTER_NORMAL; + } +} + +/* + * 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) +{ + return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY); +} + +static inline uint64_t l2meta_cow_start(QCowL2Meta *m) +{ + return m->offset + m->cow_start.offset; +} + +static inline uint64_t l2meta_cow_end(QCowL2Meta *m) +{ + return m->offset + m->cow_end.offset + m->cow_end.nb_bytes; +} + +static inline uint64_t refcount_diff(uint64_t r1, uint64_t r2) +{ + return r1 > r2 ? r1 - r2 : r2 - r1; +} + +static inline +uint32_t offset_to_reftable_index(BDRVQcow2State *s, uint64_t offset) +{ + return offset >> (s->refcount_block_bits + s->cluster_bits); +} + +/* qcow2.c functions */ +int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size, + int refcount_order, bool generous_increase, + uint64_t *refblock_count); + +int qcow2_mark_dirty(BlockDriverState *bs); +int qcow2_mark_corrupt(BlockDriverState *bs); +int qcow2_mark_consistent(BlockDriverState *bs); +int qcow2_update_header(BlockDriverState *bs); + +void qcow2_signal_corruption(BlockDriverState *bs, bool fatal, int64_t offset, + int64_t size, const char *message_format, ...) + GCC_FMT_ATTR(5, 6); + +int qcow2_validate_table(BlockDriverState *bs, uint64_t offset, + uint64_t entries, size_t entry_len, + int64_t max_size_bytes, const char *table_name, + Error **errp); + +/* qcow2-refcount.c functions */ +int qcow2_refcount_init(BlockDriverState *bs); +void qcow2_refcount_close(BlockDriverState *bs); + +int qcow2_get_refcount(BlockDriverState *bs, int64_t cluster_index, + uint64_t *refcount); + +int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index, + uint64_t addend, bool decrease, + enum qcow2_discard_type type); + +int64_t qcow2_refcount_area(BlockDriverState *bs, uint64_t offset, + uint64_t additional_clusters, bool exact_size, + int new_refblock_index, + uint64_t new_refblock_offset); + +int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size); +int64_t qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, + int64_t nb_clusters); +int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); +void qcow2_free_clusters(BlockDriverState *bs, + int64_t offset, int64_t size, + 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 coroutine_fn qcow2_flush_caches(BlockDriverState *bs); +int coroutine_fn qcow2_write_caches(BlockDriverState *bs); +int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, + BdrvCheckMode fix); + +void qcow2_process_discards(BlockDriverState *bs, int ret); + +int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset, + int64_t size); +int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset, + int64_t size, bool data_file); +int qcow2_inc_refcounts_imrt(BlockDriverState *bs, BdrvCheckResult *res, + void **refcount_table, + int64_t *refcount_table_size, + int64_t offset, int64_t size); + +int qcow2_change_refcount_order(BlockDriverState *bs, int refcount_order, + BlockDriverAmendStatusCB *status_cb, + void *cb_opaque, Error **errp); +int qcow2_shrink_reftable(BlockDriverState *bs); +int64_t qcow2_get_last_cluster(BlockDriverState *bs, int64_t size); +int qcow2_detect_metadata_preallocation(BlockDriverState *bs); + +/* qcow2-cluster.c functions */ +int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size, + bool exact_size); +int qcow2_shrink_l1_table(BlockDriverState *bs, uint64_t max_size); +int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index); +int qcow2_encrypt_sectors(BDRVQcow2State *s, int64_t sector_num, + uint8_t *buf, int nb_sectors, bool enc, Error **errp); + +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_subcluster_zeroize(BlockDriverState *bs, uint64_t offset, + uint64_t bytes, int flags); + +int qcow2_expand_zero_clusters(BlockDriverState *bs, + BlockDriverAmendStatusCB *status_cb, + void *cb_opaque); + +/* qcow2-snapshot.c functions */ +int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); +int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); +int qcow2_snapshot_delete(BlockDriverState *bs, + const char *snapshot_id, + const char *name, + Error **errp); +int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); +int qcow2_snapshot_load_tmp(BlockDriverState *bs, + const char *snapshot_id, + const char *name, + Error **errp); + +void qcow2_free_snapshots(BlockDriverState *bs); +int qcow2_read_snapshots(BlockDriverState *bs, Error **errp); +int qcow2_write_snapshots(BlockDriverState *bs); + +int coroutine_fn qcow2_check_read_snapshot_table(BlockDriverState *bs, + BdrvCheckResult *result, + BdrvCheckMode fix); +int coroutine_fn qcow2_check_fix_snapshot_table(BlockDriverState *bs, + BdrvCheckResult *result, + BdrvCheckMode fix); + +/* qcow2-cache.c functions */ +Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, + unsigned table_size); +int qcow2_cache_destroy(Qcow2Cache *c); + +void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); +int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); +int qcow2_cache_write(BlockDriverState *bs, Qcow2Cache *c); +int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, + Qcow2Cache *dependency); +void qcow2_cache_depends_on_flush(Qcow2Cache *c); + +void qcow2_cache_clean_unused(Qcow2Cache *c); +int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c); + +int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, + void **table); +int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, + void **table); +void qcow2_cache_put(Qcow2Cache *c, void **table); +void *qcow2_cache_is_table_offset(Qcow2Cache *c, uint64_t offset); +void qcow2_cache_discard(Qcow2Cache *c, void *table); + +/* qcow2-bitmap.c functions */ +int qcow2_check_bitmaps_refcounts(BlockDriverState *bs, BdrvCheckResult *res, + void **refcount_table, + int64_t *refcount_table_size); +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); +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, + const char *name, + uint32_t granularity, + Error **errp); +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, + const void *src, size_t src_size); +ssize_t coroutine_fn +qcow2_co_decompress(BlockDriverState *bs, void *dest, size_t dest_size, + const void *src, size_t src_size); +int coroutine_fn +qcow2_co_encrypt(BlockDriverState *bs, uint64_t host_offset, + uint64_t guest_offset, void *buf, size_t len); +int coroutine_fn +qcow2_co_decrypt(BlockDriverState *bs, uint64_t host_offset, + uint64_t guest_offset, void *buf, size_t len); + +#endif |