Am 08.08.2016 um 17:04 hat Vladimir Sementsov-Ogievskiy geschrieben: > Create block/qcow2-bitmap.c > Add data structures and constraints accordingly to docs/specs/qcow2.txt > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> > --- > block/Makefile.objs | 2 +- > block/qcow2-bitmap.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ > block/qcow2.h | 29 +++++++++++++++++++++++++++++ > 3 files changed, 77 insertions(+), 1 deletion(-) > create mode 100644 block/qcow2-bitmap.c > > diff --git a/block/Makefile.objs b/block/Makefile.objs > index 2593a2f..545d618 100644 > --- a/block/Makefile.objs > +++ b/block/Makefile.objs > @@ -1,5 +1,5 @@ > block-obj-y += raw_bsd.o qcow.o vdi.o vmdk.o cloop.o bochs.o vpc.o vvfat.o > -block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o > qcow2-cache.o > +block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o > qcow2-cache.o qcow2-bitmap.o > block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o > block-obj-y += qed-check.o > block-obj-$(CONFIG_VHDX) += vhdx.o vhdx-endian.o vhdx-log.o > diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c > new file mode 100644 > index 0000000..cd18b07 > --- /dev/null > +++ b/block/qcow2-bitmap.c > @@ -0,0 +1,47 @@ > +/* > + * Bitmaps for the QCOW version 2 format > + * > + * Copyright (c) 2014-2016 Vladimir Sementsov-Ogievskiy > + * > + * This file is derived from qcow2-snapshot.c, original copyright: > + * 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. > + */ > + > +/* NOTICE: BME here means Bitmaps Extension and used as a namespace for > + * _internal_ constants. Please do not use this _internal_ abbreviation for > + * other needs and/or outside of this file. */ > + > +/* Bitmap directory entry constraints */ > +#define BME_MAX_TABLE_SIZE 0x8000000 > +#define BME_MAX_PHYS_SIZE 0x20000000 /* 512 mb */ > +#define BME_MAX_GRANULARITY_BITS 31 > +#define BME_MIN_GRANULARITY_BITS 9
The spec accepts 0. Should we change the spec or at least add a note that qemu requires a minimum of 512 bytes? > +#define BME_MAX_NAME_SIZE 1023 > + > +/* Bitmap directory entry flags */ > +#define BME_RESERVED_FLAGS 0xffffffff > + > +/* bits [1, 8] U [56, 63] are reserved */ > +#define BME_TABLE_ENTRY_RESERVED_MASK 0xff000000000001fe > + > +typedef enum BitmapType { > + BT_DIRTY_TRACKING_BITMAP = 1 > +} BitmapType; > diff --git a/block/qcow2.h b/block/qcow2.h > index b36a7bf..b12cecc 100644 > --- a/block/qcow2.h > +++ b/block/qcow2.h > @@ -52,6 +52,10 @@ > * space for snapshot names and IDs */ > #define QCOW_MAX_SNAPSHOTS_SIZE (1024 * QCOW_MAX_SNAPSHOTS) > > +/* Bitmap header extension constraints */ > +#define QCOW_MAX_DIRTY_BITMAPS 65535 > +#define QCOW_MAX_DIRTY_BITMAP_DIRECTORY_SIZE (1024 * QCOW_MAX_DIRTY_BITMAPS) > + > /* 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) > */ > @@ -142,6 +146,22 @@ typedef struct QEMU_PACKED QCowSnapshotHeader { > /* name follows */ > } QCowSnapshotHeader; > > +/* QCow2BitmapHeader is actually a bitmap directory entry */ > +typedef struct QEMU_PACKED QCow2BitmapHeader { Why not call it Qcow2BitmapDirEntry then? > + /* header is 8 byte aligned */ > + uint64_t bitmap_table_offset; > + > + uint32_t bitmap_table_size; > + uint32_t flags; > + > + uint8_t type; > + uint8_t granularity_bits; > + uint16_t name_size; > + uint32_t extra_data_size; > + /* extra data follows */ > + /* name follows */ > +} QCow2BitmapHeader; > + > typedef struct QEMU_PACKED QCowSnapshotExtraData { > uint64_t vm_state_size_large; > uint64_t disk_size; > @@ -222,6 +242,15 @@ typedef uint64_t Qcow2GetRefcountFunc(const void > *refcount_array, > typedef void Qcow2SetRefcountFunc(void *refcount_array, > uint64_t index, uint64_t value); > > +/* Be careful, Qcow2BitmapHeaderExt is not an extension of > QCow2BitmapHeader, it > + * is Qcow2 header extension */ Misunderstanding already avoided with Qcow2BitmapDirEntry. :-) > +typedef struct Qcow2BitmapHeaderExt { > + uint32_t nb_bitmaps; > + uint32_t reserved32; > + uint64_t bitmap_directory_size; > + uint64_t bitmap_directory_offset; > +} QEMU_PACKED Qcow2BitmapHeaderExt; Looks good otherwise. Kevin