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-rw-r--r--block/qcow.c1212
1 files changed, 1212 insertions, 0 deletions
diff --git a/block/qcow.c b/block/qcow.c
new file mode 100644
index 000000000..c39940f33
--- /dev/null
+++ b/block/qcow.c
@@ -0,0 +1,1212 @@
+/*
+ * Block driver for the QCOW 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.
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "block/block_int.h"
+#include "block/qdict.h"
+#include "sysemu/block-backend.h"
+#include "qemu/module.h"
+#include "qemu/option.h"
+#include "qemu/bswap.h"
+#include "qemu/cutils.h"
+#include <zlib.h>
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qstring.h"
+#include "qapi/qobject-input-visitor.h"
+#include "qapi/qapi-visit-block-core.h"
+#include "crypto/block.h"
+#include "migration/blocker.h"
+#include "crypto.h"
+
+/**************************************************************/
+/* QEMU COW block driver with compression and encryption support */
+
+#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
+#define QCOW_VERSION 1
+
+#define QCOW_CRYPT_NONE 0
+#define QCOW_CRYPT_AES 1
+
+#define QCOW_OFLAG_COMPRESSED (1LL << 63)
+
+typedef struct QCowHeader {
+ uint32_t magic;
+ uint32_t version;
+ uint64_t backing_file_offset;
+ uint32_t backing_file_size;
+ uint32_t mtime;
+ uint64_t size; /* in bytes */
+ uint8_t cluster_bits;
+ uint8_t l2_bits;
+ uint16_t padding;
+ uint32_t crypt_method;
+ uint64_t l1_table_offset;
+} QEMU_PACKED QCowHeader;
+
+#define L2_CACHE_SIZE 16
+
+typedef struct BDRVQcowState {
+ int cluster_bits;
+ int cluster_size;
+ int l2_bits;
+ int l2_size;
+ unsigned int l1_size;
+ uint64_t cluster_offset_mask;
+ uint64_t l1_table_offset;
+ uint64_t *l1_table;
+ uint64_t *l2_cache;
+ uint64_t l2_cache_offsets[L2_CACHE_SIZE];
+ uint32_t l2_cache_counts[L2_CACHE_SIZE];
+ uint8_t *cluster_cache;
+ uint8_t *cluster_data;
+ uint64_t cluster_cache_offset;
+ QCryptoBlock *crypto; /* Disk encryption format driver */
+ uint32_t crypt_method_header;
+ CoMutex lock;
+ Error *migration_blocker;
+} BDRVQcowState;
+
+static QemuOptsList qcow_create_opts;
+
+static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
+
+static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
+{
+ const QCowHeader *cow_header = (const void *)buf;
+
+ if (buf_size >= sizeof(QCowHeader) &&
+ be32_to_cpu(cow_header->magic) == QCOW_MAGIC &&
+ be32_to_cpu(cow_header->version) == QCOW_VERSION)
+ return 100;
+ else
+ return 0;
+}
+
+static int qcow_open(BlockDriverState *bs, QDict *options, int flags,
+ Error **errp)
+{
+ BDRVQcowState *s = bs->opaque;
+ unsigned int len, i, shift;
+ int ret;
+ QCowHeader header;
+ QCryptoBlockOpenOptions *crypto_opts = NULL;
+ unsigned int cflags = 0;
+ QDict *encryptopts = NULL;
+ const char *encryptfmt;
+
+ qdict_extract_subqdict(options, &encryptopts, "encrypt.");
+ encryptfmt = qdict_get_try_str(encryptopts, "format");
+
+ bs->file = bdrv_open_child(NULL, options, "file", bs, &child_of_bds,
+ BDRV_CHILD_IMAGE, false, errp);
+ if (!bs->file) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
+ if (ret < 0) {
+ goto fail;
+ }
+ header.magic = be32_to_cpu(header.magic);
+ header.version = be32_to_cpu(header.version);
+ header.backing_file_offset = be64_to_cpu(header.backing_file_offset);
+ header.backing_file_size = be32_to_cpu(header.backing_file_size);
+ header.mtime = be32_to_cpu(header.mtime);
+ header.size = be64_to_cpu(header.size);
+ header.crypt_method = be32_to_cpu(header.crypt_method);
+ header.l1_table_offset = be64_to_cpu(header.l1_table_offset);
+
+ if (header.magic != QCOW_MAGIC) {
+ error_setg(errp, "Image not in qcow format");
+ ret = -EINVAL;
+ goto fail;
+ }
+ if (header.version != QCOW_VERSION) {
+ error_setg(errp, "qcow (v%d) does not support qcow version %" PRIu32,
+ QCOW_VERSION, header.version);
+ if (header.version == 2 || header.version == 3) {
+ error_append_hint(errp, "Try the 'qcow2' driver instead.\n");
+ }
+
+ ret = -ENOTSUP;
+ goto fail;
+ }
+
+ if (header.size <= 1) {
+ error_setg(errp, "Image size is too small (must be at least 2 bytes)");
+ ret = -EINVAL;
+ goto fail;
+ }
+ if (header.cluster_bits < 9 || header.cluster_bits > 16) {
+ error_setg(errp, "Cluster size must be between 512 and 64k");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* l2_bits specifies number of entries; storing a uint64_t in each entry,
+ * so bytes = num_entries << 3. */
+ if (header.l2_bits < 9 - 3 || header.l2_bits > 16 - 3) {
+ error_setg(errp, "L2 table size must be between 512 and 64k");
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ s->crypt_method_header = header.crypt_method;
+ if (s->crypt_method_header) {
+ if (bdrv_uses_whitelist() &&
+ s->crypt_method_header == QCOW_CRYPT_AES) {
+ error_setg(errp,
+ "Use of AES-CBC encrypted qcow images is no longer "
+ "supported in system emulators");
+ error_append_hint(errp,
+ "You can use 'qemu-img convert' to convert your "
+ "image to an alternative supported format, such "
+ "as unencrypted qcow, or raw with the LUKS "
+ "format instead.\n");
+ ret = -ENOSYS;
+ goto fail;
+ }
+ if (s->crypt_method_header == QCOW_CRYPT_AES) {
+ if (encryptfmt && !g_str_equal(encryptfmt, "aes")) {
+ error_setg(errp,
+ "Header reported 'aes' encryption format but "
+ "options specify '%s'", encryptfmt);
+ ret = -EINVAL;
+ goto fail;
+ }
+ qdict_put_str(encryptopts, "format", "qcow");
+ crypto_opts = block_crypto_open_opts_init(encryptopts, errp);
+ if (!crypto_opts) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ if (flags & BDRV_O_NO_IO) {
+ cflags |= QCRYPTO_BLOCK_OPEN_NO_IO;
+ }
+ s->crypto = qcrypto_block_open(crypto_opts, "encrypt.",
+ NULL, NULL, cflags, 1, errp);
+ if (!s->crypto) {
+ ret = -EINVAL;
+ goto fail;
+ }
+ } else {
+ error_setg(errp, "invalid encryption method in qcow header");
+ ret = -EINVAL;
+ goto fail;
+ }
+ bs->encrypted = true;
+ } else {
+ if (encryptfmt) {
+ error_setg(errp, "No encryption in image header, but options "
+ "specified format '%s'", encryptfmt);
+ ret = -EINVAL;
+ goto fail;
+ }
+ }
+ s->cluster_bits = header.cluster_bits;
+ s->cluster_size = 1 << s->cluster_bits;
+ s->l2_bits = header.l2_bits;
+ s->l2_size = 1 << s->l2_bits;
+ bs->total_sectors = header.size / 512;
+ s->cluster_offset_mask = (1LL << (63 - s->cluster_bits)) - 1;
+
+ /* read the level 1 table */
+ shift = s->cluster_bits + s->l2_bits;
+ if (header.size > UINT64_MAX - (1LL << shift)) {
+ error_setg(errp, "Image too large");
+ ret = -EINVAL;
+ goto fail;
+ } else {
+ uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
+ if (l1_size > INT_MAX / sizeof(uint64_t)) {
+ error_setg(errp, "Image too large");
+ ret = -EINVAL;
+ goto fail;
+ }
+ s->l1_size = l1_size;
+ }
+
+ s->l1_table_offset = header.l1_table_offset;
+ s->l1_table = g_try_new(uint64_t, s->l1_size);
+ if (s->l1_table == NULL) {
+ error_setg(errp, "Could not allocate memory for L1 table");
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ ret = bdrv_pread(bs->file, s->l1_table_offset, s->l1_table,
+ s->l1_size * sizeof(uint64_t));
+ if (ret < 0) {
+ goto fail;
+ }
+
+ for(i = 0;i < s->l1_size; i++) {
+ s->l1_table[i] = be64_to_cpu(s->l1_table[i]);
+ }
+
+ /* alloc L2 cache (max. 64k * 16 * 8 = 8 MB) */
+ s->l2_cache =
+ qemu_try_blockalign(bs->file->bs,
+ s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
+ if (s->l2_cache == NULL) {
+ error_setg(errp, "Could not allocate L2 table cache");
+ ret = -ENOMEM;
+ goto fail;
+ }
+ s->cluster_cache = g_malloc(s->cluster_size);
+ s->cluster_data = g_malloc(s->cluster_size);
+ s->cluster_cache_offset = -1;
+
+ /* read the backing file name */
+ if (header.backing_file_offset != 0) {
+ len = header.backing_file_size;
+ if (len > 1023 || len >= sizeof(bs->backing_file)) {
+ error_setg(errp, "Backing file name too long");
+ ret = -EINVAL;
+ goto fail;
+ }
+ ret = bdrv_pread(bs->file, header.backing_file_offset,
+ bs->auto_backing_file, len);
+ if (ret < 0) {
+ goto fail;
+ }
+ bs->auto_backing_file[len] = '\0';
+ pstrcpy(bs->backing_file, sizeof(bs->backing_file),
+ bs->auto_backing_file);
+ }
+
+ /* Disable migration when qcow images are used */
+ error_setg(&s->migration_blocker, "The qcow format used by node '%s' "
+ "does not support live migration",
+ bdrv_get_device_or_node_name(bs));
+ ret = migrate_add_blocker(s->migration_blocker, errp);
+ if (ret < 0) {
+ error_free(s->migration_blocker);
+ goto fail;
+ }
+
+ qobject_unref(encryptopts);
+ qapi_free_QCryptoBlockOpenOptions(crypto_opts);
+ qemu_co_mutex_init(&s->lock);
+ return 0;
+
+ fail:
+ g_free(s->l1_table);
+ qemu_vfree(s->l2_cache);
+ g_free(s->cluster_cache);
+ g_free(s->cluster_data);
+ qcrypto_block_free(s->crypto);
+ qobject_unref(encryptopts);
+ qapi_free_QCryptoBlockOpenOptions(crypto_opts);
+ return ret;
+}
+
+
+/* We have nothing to do for QCOW reopen, stubs just return
+ * success */
+static int qcow_reopen_prepare(BDRVReopenState *state,
+ BlockReopenQueue *queue, Error **errp)
+{
+ return 0;
+}
+
+
+/* 'allocate' is:
+ *
+ * 0 to not allocate.
+ *
+ * 1 to allocate a normal cluster (for sector-aligned byte offsets 'n_start'
+ * to 'n_end' within the cluster)
+ *
+ * 2 to allocate a compressed cluster of size
+ * 'compressed_size'. 'compressed_size' must be > 0 and <
+ * cluster_size
+ *
+ * return 0 if not allocated, 1 if *result is assigned, and negative
+ * errno on failure.
+ */
+static int get_cluster_offset(BlockDriverState *bs,
+ uint64_t offset, int allocate,
+ int compressed_size,
+ int n_start, int n_end, uint64_t *result)
+{
+ BDRVQcowState *s = bs->opaque;
+ int min_index, i, j, l1_index, l2_index, ret;
+ int64_t l2_offset;
+ uint64_t *l2_table, cluster_offset, tmp;
+ uint32_t min_count;
+ int new_l2_table;
+
+ *result = 0;
+ l1_index = offset >> (s->l2_bits + s->cluster_bits);
+ l2_offset = s->l1_table[l1_index];
+ new_l2_table = 0;
+ if (!l2_offset) {
+ if (!allocate)
+ return 0;
+ /* allocate a new l2 entry */
+ l2_offset = bdrv_getlength(bs->file->bs);
+ if (l2_offset < 0) {
+ return l2_offset;
+ }
+ /* round to cluster size */
+ l2_offset = QEMU_ALIGN_UP(l2_offset, s->cluster_size);
+ /* update the L1 entry */
+ s->l1_table[l1_index] = l2_offset;
+ tmp = cpu_to_be64(l2_offset);
+ BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
+ ret = bdrv_pwrite_sync(bs->file,
+ s->l1_table_offset + l1_index * sizeof(tmp),
+ &tmp, sizeof(tmp));
+ if (ret < 0) {
+ return ret;
+ }
+ new_l2_table = 1;
+ }
+ for(i = 0; i < L2_CACHE_SIZE; i++) {
+ if (l2_offset == s->l2_cache_offsets[i]) {
+ /* increment the hit count */
+ if (++s->l2_cache_counts[i] == 0xffffffff) {
+ for(j = 0; j < L2_CACHE_SIZE; j++) {
+ s->l2_cache_counts[j] >>= 1;
+ }
+ }
+ l2_table = s->l2_cache + (i << s->l2_bits);
+ goto found;
+ }
+ }
+ /* not found: load a new entry in the least used one */
+ min_index = 0;
+ min_count = 0xffffffff;
+ for(i = 0; i < L2_CACHE_SIZE; i++) {
+ if (s->l2_cache_counts[i] < min_count) {
+ min_count = s->l2_cache_counts[i];
+ min_index = i;
+ }
+ }
+ l2_table = s->l2_cache + (min_index << s->l2_bits);
+ BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
+ if (new_l2_table) {
+ memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
+ ret = bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
+ s->l2_size * sizeof(uint64_t));
+ if (ret < 0) {
+ return ret;
+ }
+ } else {
+ ret = bdrv_pread(bs->file, l2_offset, l2_table,
+ s->l2_size * sizeof(uint64_t));
+ if (ret < 0) {
+ return ret;
+ }
+ }
+ s->l2_cache_offsets[min_index] = l2_offset;
+ s->l2_cache_counts[min_index] = 1;
+ found:
+ l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
+ cluster_offset = be64_to_cpu(l2_table[l2_index]);
+ if (!cluster_offset ||
+ ((cluster_offset & QCOW_OFLAG_COMPRESSED) && allocate == 1)) {
+ if (!allocate)
+ return 0;
+ BLKDBG_EVENT(bs->file, BLKDBG_CLUSTER_ALLOC);
+ assert(QEMU_IS_ALIGNED(n_start | n_end, BDRV_SECTOR_SIZE));
+ /* allocate a new cluster */
+ if ((cluster_offset & QCOW_OFLAG_COMPRESSED) &&
+ (n_end - n_start) < s->cluster_size) {
+ /* if the cluster is already compressed, we must
+ decompress it in the case it is not completely
+ overwritten */
+ if (decompress_cluster(bs, cluster_offset) < 0) {
+ return -EIO;
+ }
+ cluster_offset = bdrv_getlength(bs->file->bs);
+ if ((int64_t) cluster_offset < 0) {
+ return cluster_offset;
+ }
+ cluster_offset = QEMU_ALIGN_UP(cluster_offset, s->cluster_size);
+ /* write the cluster content */
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
+ ret = bdrv_pwrite(bs->file, cluster_offset, s->cluster_cache,
+ s->cluster_size);
+ if (ret < 0) {
+ return ret;
+ }
+ } else {
+ cluster_offset = bdrv_getlength(bs->file->bs);
+ if ((int64_t) cluster_offset < 0) {
+ return cluster_offset;
+ }
+ if (allocate == 1) {
+ /* round to cluster size */
+ cluster_offset = QEMU_ALIGN_UP(cluster_offset, s->cluster_size);
+ if (cluster_offset + s->cluster_size > INT64_MAX) {
+ return -E2BIG;
+ }
+ ret = bdrv_truncate(bs->file, cluster_offset + s->cluster_size,
+ false, PREALLOC_MODE_OFF, 0, NULL);
+ if (ret < 0) {
+ return ret;
+ }
+ /* if encrypted, we must initialize the cluster
+ content which won't be written */
+ if (bs->encrypted &&
+ (n_end - n_start) < s->cluster_size) {
+ uint64_t start_offset;
+ assert(s->crypto);
+ start_offset = offset & ~(s->cluster_size - 1);
+ for (i = 0; i < s->cluster_size; i += BDRV_SECTOR_SIZE) {
+ if (i < n_start || i >= n_end) {
+ memset(s->cluster_data, 0x00, BDRV_SECTOR_SIZE);
+ if (qcrypto_block_encrypt(s->crypto,
+ start_offset + i,
+ s->cluster_data,
+ BDRV_SECTOR_SIZE,
+ NULL) < 0) {
+ return -EIO;
+ }
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
+ ret = bdrv_pwrite(bs->file,
+ cluster_offset + i,
+ s->cluster_data,
+ BDRV_SECTOR_SIZE);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+ }
+ }
+ } else if (allocate == 2) {
+ cluster_offset |= QCOW_OFLAG_COMPRESSED |
+ (uint64_t)compressed_size << (63 - s->cluster_bits);
+ }
+ }
+ /* update L2 table */
+ tmp = cpu_to_be64(cluster_offset);
+ l2_table[l2_index] = tmp;
+ if (allocate == 2) {
+ BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED);
+ } else {
+ BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE);
+ }
+ ret = bdrv_pwrite_sync(bs->file, l2_offset + l2_index * sizeof(tmp),
+ &tmp, sizeof(tmp));
+ if (ret < 0) {
+ return ret;
+ }
+ }
+ *result = cluster_offset;
+ return 1;
+}
+
+static int coroutine_fn qcow_co_block_status(BlockDriverState *bs,
+ bool want_zero,
+ int64_t offset, int64_t bytes,
+ int64_t *pnum, int64_t *map,
+ BlockDriverState **file)
+{
+ BDRVQcowState *s = bs->opaque;
+ int index_in_cluster, ret;
+ int64_t n;
+ uint64_t cluster_offset;
+
+ qemu_co_mutex_lock(&s->lock);
+ ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset);
+ qemu_co_mutex_unlock(&s->lock);
+ if (ret < 0) {
+ return ret;
+ }
+ index_in_cluster = offset & (s->cluster_size - 1);
+ n = s->cluster_size - index_in_cluster;
+ if (n > bytes) {
+ n = bytes;
+ }
+ *pnum = n;
+ if (!cluster_offset) {
+ return 0;
+ }
+ if ((cluster_offset & QCOW_OFLAG_COMPRESSED) || s->crypto) {
+ return BDRV_BLOCK_DATA;
+ }
+ *map = cluster_offset | index_in_cluster;
+ *file = bs->file->bs;
+ return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID;
+}
+
+static int decompress_buffer(uint8_t *out_buf, int out_buf_size,
+ const uint8_t *buf, int buf_size)
+{
+ z_stream strm1, *strm = &strm1;
+ int ret, out_len;
+
+ memset(strm, 0, sizeof(*strm));
+
+ strm->next_in = (uint8_t *)buf;
+ strm->avail_in = buf_size;
+ strm->next_out = out_buf;
+ strm->avail_out = out_buf_size;
+
+ ret = inflateInit2(strm, -12);
+ if (ret != Z_OK)
+ return -1;
+ ret = inflate(strm, Z_FINISH);
+ out_len = strm->next_out - out_buf;
+ if ((ret != Z_STREAM_END && ret != Z_BUF_ERROR) ||
+ out_len != out_buf_size) {
+ inflateEnd(strm);
+ return -1;
+ }
+ inflateEnd(strm);
+ return 0;
+}
+
+static int decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset)
+{
+ BDRVQcowState *s = bs->opaque;
+ int ret, csize;
+ uint64_t coffset;
+
+ coffset = cluster_offset & s->cluster_offset_mask;
+ if (s->cluster_cache_offset != coffset) {
+ csize = cluster_offset >> (63 - s->cluster_bits);
+ csize &= (s->cluster_size - 1);
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
+ ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize);
+ if (ret != csize)
+ return -1;
+ if (decompress_buffer(s->cluster_cache, s->cluster_size,
+ s->cluster_data, csize) < 0) {
+ return -1;
+ }
+ s->cluster_cache_offset = coffset;
+ }
+ return 0;
+}
+
+static void qcow_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+ /* At least encrypted images require 512-byte alignment. Apply the
+ * limit universally, rather than just on encrypted images, as
+ * it's easier to let the block layer handle rounding than to
+ * audit this code further. */
+ bs->bl.request_alignment = BDRV_SECTOR_SIZE;
+}
+
+static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, int64_t offset,
+ int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags)
+{
+ BDRVQcowState *s = bs->opaque;
+ int offset_in_cluster;
+ int ret = 0, n;
+ uint64_t cluster_offset;
+ uint8_t *buf;
+ void *orig_buf;
+
+ assert(!flags);
+ if (qiov->niov > 1) {
+ buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
+ if (buf == NULL) {
+ return -ENOMEM;
+ }
+ } else {
+ orig_buf = NULL;
+ buf = (uint8_t *)qiov->iov->iov_base;
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+
+ while (bytes != 0) {
+ /* prepare next request */
+ ret = get_cluster_offset(bs, offset, 0, 0, 0, 0, &cluster_offset);
+ if (ret < 0) {
+ break;
+ }
+ offset_in_cluster = offset & (s->cluster_size - 1);
+ n = s->cluster_size - offset_in_cluster;
+ if (n > bytes) {
+ n = bytes;
+ }
+
+ if (!cluster_offset) {
+ if (bs->backing) {
+ /* read from the base image */
+ qemu_co_mutex_unlock(&s->lock);
+ /* qcow2 emits this on bs->file instead of bs->backing */
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
+ ret = bdrv_co_pread(bs->backing, offset, n, buf, 0);
+ qemu_co_mutex_lock(&s->lock);
+ if (ret < 0) {
+ break;
+ }
+ } else {
+ /* Note: in this case, no need to wait */
+ memset(buf, 0, n);
+ }
+ } else if (cluster_offset & QCOW_OFLAG_COMPRESSED) {
+ /* add AIO support for compressed blocks ? */
+ if (decompress_cluster(bs, cluster_offset) < 0) {
+ ret = -EIO;
+ break;
+ }
+ memcpy(buf, s->cluster_cache + offset_in_cluster, n);
+ } else {
+ if ((cluster_offset & 511) != 0) {
+ ret = -EIO;
+ break;
+ }
+ qemu_co_mutex_unlock(&s->lock);
+ BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
+ ret = bdrv_co_pread(bs->file, cluster_offset + offset_in_cluster,
+ n, buf, 0);
+ qemu_co_mutex_lock(&s->lock);
+ if (ret < 0) {
+ break;
+ }
+ if (bs->encrypted) {
+ assert(s->crypto);
+ if (qcrypto_block_decrypt(s->crypto,
+ offset, buf, n, NULL) < 0) {
+ ret = -EIO;
+ break;
+ }
+ }
+ }
+ ret = 0;
+
+ bytes -= n;
+ offset += n;
+ buf += n;
+ }
+
+ qemu_co_mutex_unlock(&s->lock);
+
+ if (qiov->niov > 1) {
+ qemu_iovec_from_buf(qiov, 0, orig_buf, qiov->size);
+ qemu_vfree(orig_buf);
+ }
+
+ return ret;
+}
+
+static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, int64_t offset,
+ int64_t bytes, QEMUIOVector *qiov,
+ BdrvRequestFlags flags)
+{
+ BDRVQcowState *s = bs->opaque;
+ int offset_in_cluster;
+ uint64_t cluster_offset;
+ int ret = 0, n;
+ uint8_t *buf;
+ void *orig_buf;
+
+ assert(!flags);
+ s->cluster_cache_offset = -1; /* disable compressed cache */
+
+ /* We must always copy the iov when encrypting, so we
+ * don't modify the original data buffer during encryption */
+ if (bs->encrypted || qiov->niov > 1) {
+ buf = orig_buf = qemu_try_blockalign(bs, qiov->size);
+ if (buf == NULL) {
+ return -ENOMEM;
+ }
+ qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
+ } else {
+ orig_buf = NULL;
+ buf = (uint8_t *)qiov->iov->iov_base;
+ }
+
+ qemu_co_mutex_lock(&s->lock);
+
+ while (bytes != 0) {
+ offset_in_cluster = offset & (s->cluster_size - 1);
+ n = s->cluster_size - offset_in_cluster;
+ if (n > bytes) {
+ n = bytes;
+ }
+ ret = get_cluster_offset(bs, offset, 1, 0, offset_in_cluster,
+ offset_in_cluster + n, &cluster_offset);
+ if (ret < 0) {
+ break;
+ }
+ if (!cluster_offset || (cluster_offset & 511) != 0) {
+ ret = -EIO;
+ break;
+ }
+ if (bs->encrypted) {
+ assert(s->crypto);
+ if (qcrypto_block_encrypt(s->crypto, offset, buf, n, NULL) < 0) {
+ ret = -EIO;
+ break;
+ }
+ }
+
+ qemu_co_mutex_unlock(&s->lock);
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
+ ret = bdrv_co_pwrite(bs->file, cluster_offset + offset_in_cluster,
+ n, buf, 0);
+ qemu_co_mutex_lock(&s->lock);
+ if (ret < 0) {
+ break;
+ }
+ ret = 0;
+
+ bytes -= n;
+ offset += n;
+ buf += n;
+ }
+ qemu_co_mutex_unlock(&s->lock);
+
+ qemu_vfree(orig_buf);
+
+ return ret;
+}
+
+static void qcow_close(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+
+ qcrypto_block_free(s->crypto);
+ s->crypto = NULL;
+ g_free(s->l1_table);
+ qemu_vfree(s->l2_cache);
+ g_free(s->cluster_cache);
+ g_free(s->cluster_data);
+
+ migrate_del_blocker(s->migration_blocker);
+ error_free(s->migration_blocker);
+}
+
+static int coroutine_fn qcow_co_create(BlockdevCreateOptions *opts,
+ Error **errp)
+{
+ BlockdevCreateOptionsQcow *qcow_opts;
+ int header_size, backing_filename_len, l1_size, shift, i;
+ QCowHeader header;
+ uint8_t *tmp;
+ int64_t total_size = 0;
+ int ret;
+ BlockDriverState *bs;
+ BlockBackend *qcow_blk;
+ QCryptoBlock *crypto = NULL;
+
+ assert(opts->driver == BLOCKDEV_DRIVER_QCOW);
+ qcow_opts = &opts->u.qcow;
+
+ /* Sanity checks */
+ total_size = qcow_opts->size;
+ if (total_size == 0) {
+ error_setg(errp, "Image size is too small, cannot be zero length");
+ return -EINVAL;
+ }
+
+ if (qcow_opts->has_encrypt &&
+ qcow_opts->encrypt->format != Q_CRYPTO_BLOCK_FORMAT_QCOW)
+ {
+ error_setg(errp, "Unsupported encryption format");
+ return -EINVAL;
+ }
+
+ /* Create BlockBackend to write to the image */
+ bs = bdrv_open_blockdev_ref(qcow_opts->file, errp);
+ if (bs == NULL) {
+ return -EIO;
+ }
+
+ qcow_blk = blk_new_with_bs(bs, BLK_PERM_WRITE | BLK_PERM_RESIZE,
+ BLK_PERM_ALL, errp);
+ if (!qcow_blk) {
+ ret = -EPERM;
+ goto exit;
+ }
+ blk_set_allow_write_beyond_eof(qcow_blk, true);
+
+ /* Create image format */
+ memset(&header, 0, sizeof(header));
+ header.magic = cpu_to_be32(QCOW_MAGIC);
+ header.version = cpu_to_be32(QCOW_VERSION);
+ header.size = cpu_to_be64(total_size);
+ header_size = sizeof(header);
+ backing_filename_len = 0;
+ if (qcow_opts->has_backing_file) {
+ if (strcmp(qcow_opts->backing_file, "fat:")) {
+ header.backing_file_offset = cpu_to_be64(header_size);
+ backing_filename_len = strlen(qcow_opts->backing_file);
+ header.backing_file_size = cpu_to_be32(backing_filename_len);
+ header_size += backing_filename_len;
+ } else {
+ /* special backing file for vvfat */
+ qcow_opts->has_backing_file = false;
+ }
+ header.cluster_bits = 9; /* 512 byte cluster to avoid copying
+ unmodified sectors */
+ header.l2_bits = 12; /* 32 KB L2 tables */
+ } else {
+ header.cluster_bits = 12; /* 4 KB clusters */
+ header.l2_bits = 9; /* 4 KB L2 tables */
+ }
+ header_size = (header_size + 7) & ~7;
+ shift = header.cluster_bits + header.l2_bits;
+ l1_size = (total_size + (1LL << shift) - 1) >> shift;
+
+ header.l1_table_offset = cpu_to_be64(header_size);
+
+ if (qcow_opts->has_encrypt) {
+ header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
+
+ crypto = qcrypto_block_create(qcow_opts->encrypt, "encrypt.",
+ NULL, NULL, NULL, errp);
+ if (!crypto) {
+ ret = -EINVAL;
+ goto exit;
+ }
+ } else {
+ header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
+ }
+
+ /* write all the data */
+ ret = blk_pwrite(qcow_blk, 0, &header, sizeof(header), 0);
+ if (ret != sizeof(header)) {
+ goto exit;
+ }
+
+ if (qcow_opts->has_backing_file) {
+ ret = blk_pwrite(qcow_blk, sizeof(header),
+ qcow_opts->backing_file, backing_filename_len, 0);
+ if (ret != backing_filename_len) {
+ goto exit;
+ }
+ }
+
+ tmp = g_malloc0(BDRV_SECTOR_SIZE);
+ for (i = 0; i < DIV_ROUND_UP(sizeof(uint64_t) * l1_size, BDRV_SECTOR_SIZE);
+ i++) {
+ ret = blk_pwrite(qcow_blk, header_size + BDRV_SECTOR_SIZE * i,
+ tmp, BDRV_SECTOR_SIZE, 0);
+ if (ret != BDRV_SECTOR_SIZE) {
+ g_free(tmp);
+ goto exit;
+ }
+ }
+
+ g_free(tmp);
+ ret = 0;
+exit:
+ blk_unref(qcow_blk);
+ bdrv_unref(bs);
+ qcrypto_block_free(crypto);
+ return ret;
+}
+
+static int coroutine_fn qcow_co_create_opts(BlockDriver *drv,
+ const char *filename,
+ QemuOpts *opts, Error **errp)
+{
+ BlockdevCreateOptions *create_options = NULL;
+ BlockDriverState *bs = NULL;
+ QDict *qdict = NULL;
+ Visitor *v;
+ const char *val;
+ int ret;
+ char *backing_fmt;
+
+ static const QDictRenames opt_renames[] = {
+ { BLOCK_OPT_BACKING_FILE, "backing-file" },
+ { BLOCK_OPT_ENCRYPT, BLOCK_OPT_ENCRYPT_FORMAT },
+ { NULL, NULL },
+ };
+
+ /*
+ * We can't actually store a backing format, but can check that
+ * the user's request made sense.
+ */
+ backing_fmt = qemu_opt_get_del(opts, BLOCK_OPT_BACKING_FMT);
+ if (backing_fmt && !bdrv_find_format(backing_fmt)) {
+ error_setg(errp, "unrecognized backing format '%s'", backing_fmt);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* Parse options and convert legacy syntax */
+ qdict = qemu_opts_to_qdict_filtered(opts, NULL, &qcow_create_opts, true);
+
+ val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT);
+ if (val && !strcmp(val, "on")) {
+ qdict_put_str(qdict, BLOCK_OPT_ENCRYPT, "qcow");
+ } else if (val && !strcmp(val, "off")) {
+ qdict_del(qdict, BLOCK_OPT_ENCRYPT);
+ }
+
+ val = qdict_get_try_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT);
+ if (val && !strcmp(val, "aes")) {
+ qdict_put_str(qdict, BLOCK_OPT_ENCRYPT_FORMAT, "qcow");
+ }
+
+ if (!qdict_rename_keys(qdict, opt_renames, errp)) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* Create and open the file (protocol layer) */
+ ret = bdrv_create_file(filename, opts, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ bs = bdrv_open(filename, NULL, NULL,
+ BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp);
+ if (bs == NULL) {
+ ret = -EIO;
+ goto fail;
+ }
+
+ /* Now get the QAPI type BlockdevCreateOptions */
+ qdict_put_str(qdict, "driver", "qcow");
+ qdict_put_str(qdict, "file", bs->node_name);
+
+ v = qobject_input_visitor_new_flat_confused(qdict, errp);
+ if (!v) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ visit_type_BlockdevCreateOptions(v, NULL, &create_options, errp);
+ visit_free(v);
+ if (!create_options) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ /* Silently round up size */
+ assert(create_options->driver == BLOCKDEV_DRIVER_QCOW);
+ create_options->u.qcow.size =
+ ROUND_UP(create_options->u.qcow.size, BDRV_SECTOR_SIZE);
+
+ /* Create the qcow image (format layer) */
+ ret = qcow_co_create(create_options, errp);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ ret = 0;
+fail:
+ g_free(backing_fmt);
+ qobject_unref(qdict);
+ bdrv_unref(bs);
+ qapi_free_BlockdevCreateOptions(create_options);
+ return ret;
+}
+
+static int qcow_make_empty(BlockDriverState *bs)
+{
+ BDRVQcowState *s = bs->opaque;
+ uint32_t l1_length = s->l1_size * sizeof(uint64_t);
+ int ret;
+
+ memset(s->l1_table, 0, l1_length);
+ if (bdrv_pwrite_sync(bs->file, s->l1_table_offset, s->l1_table,
+ l1_length) < 0)
+ return -1;
+ ret = bdrv_truncate(bs->file, s->l1_table_offset + l1_length, false,
+ PREALLOC_MODE_OFF, 0, NULL);
+ if (ret < 0)
+ return ret;
+
+ memset(s->l2_cache, 0, s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
+ memset(s->l2_cache_offsets, 0, L2_CACHE_SIZE * sizeof(uint64_t));
+ memset(s->l2_cache_counts, 0, L2_CACHE_SIZE * sizeof(uint32_t));
+
+ return 0;
+}
+
+/* XXX: put compressed sectors first, then all the cluster aligned
+ tables to avoid losing bytes in alignment */
+static coroutine_fn int
+qcow_co_pwritev_compressed(BlockDriverState *bs, int64_t offset, int64_t bytes,
+ QEMUIOVector *qiov)
+{
+ BDRVQcowState *s = bs->opaque;
+ z_stream strm;
+ int ret, out_len;
+ uint8_t *buf, *out_buf;
+ uint64_t cluster_offset;
+
+ buf = qemu_blockalign(bs, s->cluster_size);
+ if (bytes != s->cluster_size) {
+ if (bytes > s->cluster_size ||
+ offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS)
+ {
+ qemu_vfree(buf);
+ return -EINVAL;
+ }
+ /* Zero-pad last write if image size is not cluster aligned */
+ memset(buf + bytes, 0, s->cluster_size - bytes);
+ }
+ qemu_iovec_to_buf(qiov, 0, buf, qiov->size);
+
+ out_buf = g_malloc(s->cluster_size);
+
+ /* best compression, small window, no zlib header */
+ memset(&strm, 0, sizeof(strm));
+ ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION,
+ Z_DEFLATED, -12,
+ 9, Z_DEFAULT_STRATEGY);
+ if (ret != 0) {
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ strm.avail_in = s->cluster_size;
+ strm.next_in = (uint8_t *)buf;
+ strm.avail_out = s->cluster_size;
+ strm.next_out = out_buf;
+
+ ret = deflate(&strm, Z_FINISH);
+ if (ret != Z_STREAM_END && ret != Z_OK) {
+ deflateEnd(&strm);
+ ret = -EINVAL;
+ goto fail;
+ }
+ out_len = strm.next_out - out_buf;
+
+ deflateEnd(&strm);
+
+ if (ret != Z_STREAM_END || out_len >= s->cluster_size) {
+ /* could not compress: write normal cluster */
+ ret = qcow_co_pwritev(bs, offset, bytes, qiov, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+ goto success;
+ }
+ qemu_co_mutex_lock(&s->lock);
+ ret = get_cluster_offset(bs, offset, 2, out_len, 0, 0, &cluster_offset);
+ qemu_co_mutex_unlock(&s->lock);
+ if (ret < 0) {
+ goto fail;
+ }
+ if (cluster_offset == 0) {
+ ret = -EIO;
+ goto fail;
+ }
+ cluster_offset &= s->cluster_offset_mask;
+
+ BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
+ ret = bdrv_co_pwrite(bs->file, cluster_offset, out_len, out_buf, 0);
+ if (ret < 0) {
+ goto fail;
+ }
+success:
+ ret = 0;
+fail:
+ qemu_vfree(buf);
+ g_free(out_buf);
+ return ret;
+}
+
+static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+ BDRVQcowState *s = bs->opaque;
+ bdi->cluster_size = s->cluster_size;
+ return 0;
+}
+
+static QemuOptsList qcow_create_opts = {
+ .name = "qcow-create-opts",
+ .head = QTAILQ_HEAD_INITIALIZER(qcow_create_opts.head),
+ .desc = {
+ {
+ .name = BLOCK_OPT_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Virtual disk size"
+ },
+ {
+ .name = BLOCK_OPT_BACKING_FILE,
+ .type = QEMU_OPT_STRING,
+ .help = "File name of a base image"
+ },
+ {
+ .name = BLOCK_OPT_BACKING_FMT,
+ .type = QEMU_OPT_STRING,
+ .help = "Format of the backing image",
+ },
+ {
+ .name = BLOCK_OPT_ENCRYPT,
+ .type = QEMU_OPT_BOOL,
+ .help = "Encrypt the image with format 'aes'. (Deprecated "
+ "in favor of " BLOCK_OPT_ENCRYPT_FORMAT "=aes)",
+ },
+ {
+ .name = BLOCK_OPT_ENCRYPT_FORMAT,
+ .type = QEMU_OPT_STRING,
+ .help = "Encrypt the image, format choices: 'aes'",
+ },
+ BLOCK_CRYPTO_OPT_DEF_QCOW_KEY_SECRET("encrypt."),
+ { /* end of list */ }
+ }
+};
+
+static const char *const qcow_strong_runtime_opts[] = {
+ "encrypt." BLOCK_CRYPTO_OPT_QCOW_KEY_SECRET,
+
+ NULL
+};
+
+static BlockDriver bdrv_qcow = {
+ .format_name = "qcow",
+ .instance_size = sizeof(BDRVQcowState),
+ .bdrv_probe = qcow_probe,
+ .bdrv_open = qcow_open,
+ .bdrv_close = qcow_close,
+ .bdrv_child_perm = bdrv_default_perms,
+ .bdrv_reopen_prepare = qcow_reopen_prepare,
+ .bdrv_co_create = qcow_co_create,
+ .bdrv_co_create_opts = qcow_co_create_opts,
+ .bdrv_has_zero_init = bdrv_has_zero_init_1,
+ .is_format = true,
+ .supports_backing = true,
+ .bdrv_refresh_limits = qcow_refresh_limits,
+
+ .bdrv_co_preadv = qcow_co_preadv,
+ .bdrv_co_pwritev = qcow_co_pwritev,
+ .bdrv_co_block_status = qcow_co_block_status,
+
+ .bdrv_make_empty = qcow_make_empty,
+ .bdrv_co_pwritev_compressed = qcow_co_pwritev_compressed,
+ .bdrv_get_info = qcow_get_info,
+
+ .create_opts = &qcow_create_opts,
+ .strong_runtime_opts = qcow_strong_runtime_opts,
+};
+
+static void bdrv_qcow_init(void)
+{
+ bdrv_register(&bdrv_qcow);
+}
+
+block_init(bdrv_qcow_init);