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authorVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>2021-02-24 13:47:05 +0300
committerKevin Wolf <kwolf@redhat.com>2021-03-08 14:56:55 +0100
commitbaefd977002e72402f2cc42b11f2cb11b96aae9e (patch)
treec359e5e3915c850a4f63629ebd3c6d1491586944 /block
parente0b5207f54e45ccb7c733e736add47f7b06c5867 (diff)
parallels: support bitmap extension for read-only mode
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20210224104707.88430-5-vsementsov@virtuozzo.com> Reviewed-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/meson.build3
-rw-r--r--block/parallels-ext.c300
-rw-r--r--block/parallels.c18
-rw-r--r--block/parallels.h6
4 files changed, 325 insertions, 2 deletions
diff --git a/block/meson.build b/block/meson.build
index eeaefe5809..d21990ec95 100644
--- a/block/meson.build
+++ b/block/meson.build
@@ -57,7 +57,8 @@ block_ss.add(when: 'CONFIG_QED', if_true: files(
'qed-table.c',
'qed.c',
))
-block_ss.add(when: [libxml2, 'CONFIG_PARALLELS'], if_true: files('parallels.c'))
+block_ss.add(when: [libxml2, 'CONFIG_PARALLELS'],
+ if_true: files('parallels.c', 'parallels-ext.c'))
block_ss.add(when: 'CONFIG_WIN32', if_true: files('file-win32.c', 'win32-aio.c'))
block_ss.add(when: 'CONFIG_POSIX', if_true: [files('file-posix.c'), coref, iokit])
block_ss.add(when: libiscsi, if_true: files('iscsi-opts.c'))
diff --git a/block/parallels-ext.c b/block/parallels-ext.c
new file mode 100644
index 0000000000..e0dd0975c6
--- /dev/null
+++ b/block/parallels-ext.c
@@ -0,0 +1,300 @@
+/*
+ * Support of Parallels Format Extension. It's a part of Parallels format
+ * driver.
+ *
+ * Copyright (c) 2021 Virtuozzo International GmbH
+ *
+ * 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.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "block/block_int.h"
+#include "parallels.h"
+#include "crypto/hash.h"
+#include "qemu/uuid.h"
+
+#define PARALLELS_FORMAT_EXTENSION_MAGIC 0xAB234CEF23DCEA87ULL
+
+#define PARALLELS_END_OF_FEATURES_MAGIC 0x0ULL
+#define PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC 0x20385FAE252CB34AULL
+
+typedef struct ParallelsFormatExtensionHeader {
+ uint64_t magic; /* PARALLELS_FORMAT_EXTENSION_MAGIC */
+ uint8_t check_sum[16];
+} QEMU_PACKED ParallelsFormatExtensionHeader;
+
+typedef struct ParallelsFeatureHeader {
+ uint64_t magic;
+ uint64_t flags;
+ uint32_t data_size;
+ uint32_t _unused;
+} QEMU_PACKED ParallelsFeatureHeader;
+
+typedef struct ParallelsDirtyBitmapFeature {
+ uint64_t size;
+ uint8_t id[16];
+ uint32_t granularity;
+ uint32_t l1_size;
+ /* L1 table follows */
+} QEMU_PACKED ParallelsDirtyBitmapFeature;
+
+/* Given L1 table read bitmap data from the image and populate @bitmap */
+static int parallels_load_bitmap_data(BlockDriverState *bs,
+ const uint64_t *l1_table,
+ uint32_t l1_size,
+ BdrvDirtyBitmap *bitmap,
+ Error **errp)
+{
+ BDRVParallelsState *s = bs->opaque;
+ int ret = 0;
+ uint64_t offset, limit;
+ uint64_t bm_size = bdrv_dirty_bitmap_size(bitmap);
+ uint8_t *buf = NULL;
+ uint64_t i, tab_size =
+ DIV_ROUND_UP(bdrv_dirty_bitmap_serialization_size(bitmap, 0, bm_size),
+ s->cluster_size);
+
+ if (tab_size != l1_size) {
+ error_setg(errp, "Bitmap table size %" PRIu32 " does not correspond "
+ "to bitmap size and cluster size. Expected %" PRIu64,
+ l1_size, tab_size);
+ return -EINVAL;
+ }
+
+ buf = qemu_blockalign(bs, s->cluster_size);
+ limit = bdrv_dirty_bitmap_serialization_coverage(s->cluster_size, bitmap);
+ for (i = 0, offset = 0; i < tab_size; ++i, offset += limit) {
+ uint64_t count = MIN(bm_size - offset, limit);
+ uint64_t entry = l1_table[i];
+
+ if (entry == 0) {
+ /* No need to deserialize zeros because @bitmap is cleared. */
+ continue;
+ }
+
+ if (entry == 1) {
+ bdrv_dirty_bitmap_deserialize_ones(bitmap, offset, count, false);
+ } else {
+ ret = bdrv_pread(bs->file, entry << BDRV_SECTOR_BITS, buf,
+ s->cluster_size);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Failed to read bitmap data cluster");
+ goto finish;
+ }
+ bdrv_dirty_bitmap_deserialize_part(bitmap, buf, offset, count,
+ false);
+ }
+ }
+ ret = 0;
+
+ bdrv_dirty_bitmap_deserialize_finish(bitmap);
+
+finish:
+ qemu_vfree(buf);
+
+ return ret;
+}
+
+/*
+ * @data buffer (of @data_size size) is the Dirty bitmaps feature which
+ * consists of ParallelsDirtyBitmapFeature followed by L1 table.
+ */
+static BdrvDirtyBitmap *parallels_load_bitmap(BlockDriverState *bs,
+ uint8_t *data,
+ size_t data_size,
+ Error **errp)
+{
+ int ret;
+ ParallelsDirtyBitmapFeature bf;
+ g_autofree uint64_t *l1_table = NULL;
+ BdrvDirtyBitmap *bitmap;
+ QemuUUID uuid;
+ char uuidstr[UUID_FMT_LEN + 1];
+ int i;
+
+ if (data_size < sizeof(bf)) {
+ error_setg(errp, "Too small Bitmap Feature area in Parallels Format "
+ "Extension: %zu bytes, expected at least %zu bytes",
+ data_size, sizeof(bf));
+ return NULL;
+ }
+ memcpy(&bf, data, sizeof(bf));
+ bf.size = le64_to_cpu(bf.size);
+ bf.granularity = le32_to_cpu(bf.granularity) << BDRV_SECTOR_BITS;
+ bf.l1_size = le32_to_cpu(bf.l1_size);
+ data += sizeof(bf);
+ data_size -= sizeof(bf);
+
+ if (bf.size != bs->total_sectors) {
+ error_setg(errp, "Bitmap size (in sectors) %" PRId64 " differs from "
+ "disk size in sectors %" PRId64, bf.size, bs->total_sectors);
+ return NULL;
+ }
+
+ if (bf.l1_size * sizeof(uint64_t) > data_size) {
+ error_setg(errp, "Bitmaps feature corrupted: l1 table exceeds "
+ "extension data_size");
+ return NULL;
+ }
+
+ memcpy(&uuid, bf.id, sizeof(uuid));
+ qemu_uuid_unparse(&uuid, uuidstr);
+ bitmap = bdrv_create_dirty_bitmap(bs, bf.granularity, uuidstr, errp);
+ if (!bitmap) {
+ return NULL;
+ }
+
+ l1_table = g_new(uint64_t, bf.l1_size);
+ for (i = 0; i < bf.l1_size; i++, data += sizeof(uint64_t)) {
+ l1_table[i] = ldq_le_p(data);
+ }
+
+ ret = parallels_load_bitmap_data(bs, l1_table, bf.l1_size, bitmap, errp);
+ if (ret < 0) {
+ bdrv_release_dirty_bitmap(bitmap);
+ return NULL;
+ }
+
+ /* We support format extension only for RO parallels images. */
+ assert(!(bs->open_flags & BDRV_O_RDWR));
+ bdrv_dirty_bitmap_set_readonly(bitmap, true);
+
+ return bitmap;
+}
+
+static int parallels_parse_format_extension(BlockDriverState *bs,
+ uint8_t *ext_cluster, Error **errp)
+{
+ BDRVParallelsState *s = bs->opaque;
+ int ret;
+ int remaining = s->cluster_size;
+ uint8_t *pos = ext_cluster;
+ ParallelsFormatExtensionHeader eh;
+ g_autofree uint8_t *hash = NULL;
+ size_t hash_len = 0;
+ GSList *bitmaps = NULL, *el;
+
+ memcpy(&eh, pos, sizeof(eh));
+ eh.magic = le64_to_cpu(eh.magic);
+ pos += sizeof(eh);
+ remaining -= sizeof(eh);
+
+ if (eh.magic != PARALLELS_FORMAT_EXTENSION_MAGIC) {
+ error_setg(errp, "Wrong parallels Format Extension magic: 0x%" PRIx64
+ ", expected: 0x%llx", eh.magic,
+ PARALLELS_FORMAT_EXTENSION_MAGIC);
+ goto fail;
+ }
+
+ ret = qcrypto_hash_bytes(QCRYPTO_HASH_ALG_MD5, (char *)pos, remaining,
+ &hash, &hash_len, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ if (hash_len != sizeof(eh.check_sum) ||
+ memcmp(hash, eh.check_sum, sizeof(eh.check_sum)) != 0) {
+ error_setg(errp, "Wrong checksum in Format Extension header. Format "
+ "extension is corrupted.");
+ goto fail;
+ }
+
+ while (true) {
+ ParallelsFeatureHeader fh;
+ BdrvDirtyBitmap *bitmap;
+
+ if (remaining < sizeof(fh)) {
+ error_setg(errp, "Can not read feature header, as remaining bytes "
+ "(%d) in Format Extension is less than Feature header "
+ "size (%zu)", remaining, sizeof(fh));
+ goto fail;
+ }
+
+ memcpy(&fh, pos, sizeof(fh));
+ pos += sizeof(fh);
+ remaining -= sizeof(fh);
+
+ fh.magic = le64_to_cpu(fh.magic);
+ fh.flags = le64_to_cpu(fh.flags);
+ fh.data_size = le32_to_cpu(fh.data_size);
+
+ if (fh.flags) {
+ error_setg(errp, "Flags for extension feature are unsupported");
+ goto fail;
+ }
+
+ if (fh.data_size > remaining) {
+ error_setg(errp, "Feature data_size exceedes Format Extension "
+ "cluster");
+ goto fail;
+ }
+
+ switch (fh.magic) {
+ case PARALLELS_END_OF_FEATURES_MAGIC:
+ return 0;
+
+ case PARALLELS_DIRTY_BITMAP_FEATURE_MAGIC:
+ bitmap = parallels_load_bitmap(bs, pos, fh.data_size, errp);
+ if (!bitmap) {
+ goto fail;
+ }
+ bitmaps = g_slist_append(bitmaps, bitmap);
+ break;
+
+ default:
+ error_setg(errp, "Unknown feature: 0x%" PRIu64, fh.magic);
+ goto fail;
+ }
+
+ pos = ext_cluster + QEMU_ALIGN_UP(pos + fh.data_size - ext_cluster, 8);
+ }
+
+fail:
+ for (el = bitmaps; el; el = el->next) {
+ bdrv_release_dirty_bitmap(el->data);
+ }
+ g_slist_free(bitmaps);
+
+ return -EINVAL;
+}
+
+int parallels_read_format_extension(BlockDriverState *bs,
+ int64_t ext_off, Error **errp)
+{
+ BDRVParallelsState *s = bs->opaque;
+ int ret;
+ uint8_t *ext_cluster = qemu_blockalign(bs, s->cluster_size);
+
+ assert(ext_off > 0);
+
+ ret = bdrv_pread(bs->file, ext_off, ext_cluster, s->cluster_size);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Failed to read Format Extension cluster");
+ goto out;
+ }
+
+ ret = parallels_parse_format_extension(bs, ext_cluster, errp);
+
+out:
+ qemu_vfree(ext_cluster);
+
+ return ret;
+}
diff --git a/block/parallels.c b/block/parallels.c
index 9594d84978..6ebad2a2bb 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -29,6 +29,7 @@
*/
#include "qemu/osdep.h"
+#include "qemu/error-report.h"
#include "qapi/error.h"
#include "block/block_int.h"
#include "block/qdict.h"
@@ -843,6 +844,23 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags,
goto fail_options;
}
+ if (ph.ext_off) {
+ if (flags & BDRV_O_RDWR) {
+ /*
+ * It's unsafe to open image RW if there is an extension (as we
+ * don't support it). But parallels driver in QEMU historically
+ * ignores the extension, so print warning and don't care.
+ */
+ warn_report("Format Extension ignored in RW mode");
+ } else {
+ ret = parallels_read_format_extension(
+ bs, le64_to_cpu(ph.ext_off) << BDRV_SECTOR_BITS, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+ }
+ }
+
if ((flags & BDRV_O_RDWR) && !(flags & BDRV_O_INACTIVE)) {
s->header->inuse = cpu_to_le32(HEADER_INUSE_MAGIC);
ret = parallels_update_header(bs);
diff --git a/block/parallels.h b/block/parallels.h
index 9a9209e320..f22f43f988 100644
--- a/block/parallels.h
+++ b/block/parallels.h
@@ -48,7 +48,8 @@ typedef struct ParallelsHeader {
uint64_t nb_sectors;
uint32_t inuse;
uint32_t data_off;
- char padding[12];
+ uint32_t flags;
+ uint64_t ext_off;
} QEMU_PACKED ParallelsHeader;
typedef enum ParallelsPreallocMode {
@@ -85,4 +86,7 @@ typedef struct BDRVParallelsState {
Error *migration_blocker;
} BDRVParallelsState;
+int parallels_read_format_extension(BlockDriverState *bs,
+ int64_t ext_off, Error **errp);
+
#endif