The VM state offset is a concept internal to the image format. Replace the old bdrv_{get,put}_buffer method that require an index into the image file that is constructed from the VM state offset and an offset into the vmstate with the bdrv_{load,save}_vmstate that just take an offset into the VM state. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
1023 lines
30 KiB
C
1023 lines
30 KiB
C
/*
|
|
* 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.
|
|
*/
|
|
#include "qemu-common.h"
|
|
#include "block_int.h"
|
|
#include "module.h"
|
|
#include <zlib.h>
|
|
#include "aes.h"
|
|
#include "block/qcow2.h"
|
|
|
|
/*
|
|
Differences with QCOW:
|
|
|
|
- Support for multiple incremental snapshots.
|
|
- Memory management by reference counts.
|
|
- Clusters which have a reference count of one have the bit
|
|
QCOW_OFLAG_COPIED to optimize write performance.
|
|
- Size of compressed clusters is stored in sectors to reduce bit usage
|
|
in the cluster offsets.
|
|
- Support for storing additional data (such as the VM state) in the
|
|
snapshots.
|
|
- If a backing store is used, the cluster size is not constrained
|
|
(could be backported to QCOW).
|
|
- L2 tables have always a size of one cluster.
|
|
*/
|
|
|
|
|
|
typedef struct {
|
|
uint32_t magic;
|
|
uint32_t len;
|
|
} QCowExtension;
|
|
#define QCOW_EXT_MAGIC_END 0
|
|
#define QCOW_EXT_MAGIC_BACKING_FORMAT 0xE2792ACA
|
|
|
|
|
|
|
|
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;
|
|
}
|
|
|
|
|
|
/*
|
|
* read qcow2 extension and fill bs
|
|
* start reading from start_offset
|
|
* finish reading upon magic of value 0 or when end_offset reached
|
|
* unknown magic is skipped (future extension this version knows nothing about)
|
|
* return 0 upon success, non-0 otherwise
|
|
*/
|
|
static int qcow_read_extensions(BlockDriverState *bs, uint64_t start_offset,
|
|
uint64_t end_offset)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowExtension ext;
|
|
uint64_t offset;
|
|
|
|
#ifdef DEBUG_EXT
|
|
printf("qcow_read_extensions: start=%ld end=%ld\n", start_offset, end_offset);
|
|
#endif
|
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offset = start_offset;
|
|
while (offset < end_offset) {
|
|
|
|
#ifdef DEBUG_EXT
|
|
/* Sanity check */
|
|
if (offset > s->cluster_size)
|
|
printf("qcow_handle_extension: suspicious offset %lu\n", offset);
|
|
|
|
printf("attemting to read extended header in offset %lu\n", offset);
|
|
#endif
|
|
|
|
if (bdrv_pread(s->hd, offset, &ext, sizeof(ext)) != sizeof(ext)) {
|
|
fprintf(stderr, "qcow_handle_extension: ERROR: pread fail from offset %llu\n",
|
|
(unsigned long long)offset);
|
|
return 1;
|
|
}
|
|
be32_to_cpus(&ext.magic);
|
|
be32_to_cpus(&ext.len);
|
|
offset += sizeof(ext);
|
|
#ifdef DEBUG_EXT
|
|
printf("ext.magic = 0x%x\n", ext.magic);
|
|
#endif
|
|
switch (ext.magic) {
|
|
case QCOW_EXT_MAGIC_END:
|
|
return 0;
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|
|
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case QCOW_EXT_MAGIC_BACKING_FORMAT:
|
|
if (ext.len >= sizeof(bs->backing_format)) {
|
|
fprintf(stderr, "ERROR: ext_backing_format: len=%u too large"
|
|
" (>=%zu)\n",
|
|
ext.len, sizeof(bs->backing_format));
|
|
return 2;
|
|
}
|
|
if (bdrv_pread(s->hd, offset , bs->backing_format,
|
|
ext.len) != ext.len)
|
|
return 3;
|
|
bs->backing_format[ext.len] = '\0';
|
|
#ifdef DEBUG_EXT
|
|
printf("Qcow2: Got format extension %s\n", bs->backing_format);
|
|
#endif
|
|
offset += ((ext.len + 7) & ~7);
|
|
break;
|
|
|
|
default:
|
|
/* unknown magic -- just skip it */
|
|
offset += ((ext.len + 7) & ~7);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int len, i, shift, ret;
|
|
QCowHeader header;
|
|
uint64_t ext_end;
|
|
|
|
ret = bdrv_file_open(&s->hd, filename, flags);
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|
if (ret < 0)
|
|
return ret;
|
|
if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header))
|
|
goto fail;
|
|
be32_to_cpus(&header.magic);
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|
be32_to_cpus(&header.version);
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|
be64_to_cpus(&header.backing_file_offset);
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|
be32_to_cpus(&header.backing_file_size);
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|
be64_to_cpus(&header.size);
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|
be32_to_cpus(&header.cluster_bits);
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|
be32_to_cpus(&header.crypt_method);
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be64_to_cpus(&header.l1_table_offset);
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|
be32_to_cpus(&header.l1_size);
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be64_to_cpus(&header.refcount_table_offset);
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|
be32_to_cpus(&header.refcount_table_clusters);
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|
be64_to_cpus(&header.snapshots_offset);
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|
be32_to_cpus(&header.nb_snapshots);
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|
|
|
if (header.magic != QCOW_MAGIC || header.version != QCOW_VERSION)
|
|
goto fail;
|
|
if (header.size <= 1 ||
|
|
header.cluster_bits < MIN_CLUSTER_BITS ||
|
|
header.cluster_bits > MAX_CLUSTER_BITS)
|
|
goto fail;
|
|
if (header.crypt_method > QCOW_CRYPT_AES)
|
|
goto fail;
|
|
s->crypt_method_header = header.crypt_method;
|
|
if (s->crypt_method_header)
|
|
bs->encrypted = 1;
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|
s->cluster_bits = header.cluster_bits;
|
|
s->cluster_size = 1 << s->cluster_bits;
|
|
s->cluster_sectors = 1 << (s->cluster_bits - 9);
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|
s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */
|
|
s->l2_size = 1 << s->l2_bits;
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|
bs->total_sectors = header.size / 512;
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|
s->csize_shift = (62 - (s->cluster_bits - 8));
|
|
s->csize_mask = (1 << (s->cluster_bits - 8)) - 1;
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|
s->cluster_offset_mask = (1LL << s->csize_shift) - 1;
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|
s->refcount_table_offset = header.refcount_table_offset;
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|
s->refcount_table_size =
|
|
header.refcount_table_clusters << (s->cluster_bits - 3);
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|
|
|
s->snapshots_offset = header.snapshots_offset;
|
|
s->nb_snapshots = header.nb_snapshots;
|
|
|
|
/* read the level 1 table */
|
|
s->l1_size = header.l1_size;
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|
shift = s->cluster_bits + s->l2_bits;
|
|
s->l1_vm_state_index = (header.size + (1LL << shift) - 1) >> shift;
|
|
/* the L1 table must contain at least enough entries to put
|
|
header.size bytes */
|
|
if (s->l1_size < s->l1_vm_state_index)
|
|
goto fail;
|
|
s->l1_table_offset = header.l1_table_offset;
|
|
s->l1_table = qemu_mallocz(
|
|
align_offset(s->l1_size * sizeof(uint64_t), 512));
|
|
if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) !=
|
|
s->l1_size * sizeof(uint64_t))
|
|
goto fail;
|
|
for(i = 0;i < s->l1_size; i++) {
|
|
be64_to_cpus(&s->l1_table[i]);
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}
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|
/* alloc L2 cache */
|
|
s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint64_t));
|
|
s->cluster_cache = qemu_malloc(s->cluster_size);
|
|
/* one more sector for decompressed data alignment */
|
|
s->cluster_data = qemu_malloc(QCOW_MAX_CRYPT_CLUSTERS * s->cluster_size
|
|
+ 512);
|
|
s->cluster_cache_offset = -1;
|
|
|
|
if (qcow2_refcount_init(bs) < 0)
|
|
goto fail;
|
|
|
|
/* read qcow2 extensions */
|
|
if (header.backing_file_offset)
|
|
ext_end = header.backing_file_offset;
|
|
else
|
|
ext_end = s->cluster_size;
|
|
if (qcow_read_extensions(bs, sizeof(header), ext_end))
|
|
goto fail;
|
|
|
|
/* read the backing file name */
|
|
if (header.backing_file_offset != 0) {
|
|
len = header.backing_file_size;
|
|
if (len > 1023)
|
|
len = 1023;
|
|
if (bdrv_pread(s->hd, header.backing_file_offset, bs->backing_file, len) != len)
|
|
goto fail;
|
|
bs->backing_file[len] = '\0';
|
|
}
|
|
if (qcow2_read_snapshots(bs) < 0)
|
|
goto fail;
|
|
|
|
#ifdef DEBUG_ALLOC
|
|
qcow2_check_refcounts(bs);
|
|
#endif
|
|
return 0;
|
|
|
|
fail:
|
|
qcow2_free_snapshots(bs);
|
|
qcow2_refcount_close(bs);
|
|
qemu_free(s->l1_table);
|
|
qemu_free(s->l2_cache);
|
|
qemu_free(s->cluster_cache);
|
|
qemu_free(s->cluster_data);
|
|
bdrv_delete(s->hd);
|
|
return -1;
|
|
}
|
|
|
|
static int qcow_set_key(BlockDriverState *bs, const char *key)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
uint8_t keybuf[16];
|
|
int len, i;
|
|
|
|
memset(keybuf, 0, 16);
|
|
len = strlen(key);
|
|
if (len > 16)
|
|
len = 16;
|
|
/* XXX: we could compress the chars to 7 bits to increase
|
|
entropy */
|
|
for(i = 0;i < len;i++) {
|
|
keybuf[i] = key[i];
|
|
}
|
|
s->crypt_method = s->crypt_method_header;
|
|
|
|
if (AES_set_encrypt_key(keybuf, 128, &s->aes_encrypt_key) != 0)
|
|
return -1;
|
|
if (AES_set_decrypt_key(keybuf, 128, &s->aes_decrypt_key) != 0)
|
|
return -1;
|
|
#if 0
|
|
/* test */
|
|
{
|
|
uint8_t in[16];
|
|
uint8_t out[16];
|
|
uint8_t tmp[16];
|
|
for(i=0;i<16;i++)
|
|
in[i] = i;
|
|
AES_encrypt(in, tmp, &s->aes_encrypt_key);
|
|
AES_decrypt(tmp, out, &s->aes_decrypt_key);
|
|
for(i = 0; i < 16; i++)
|
|
printf(" %02x", tmp[i]);
|
|
printf("\n");
|
|
for(i = 0; i < 16; i++)
|
|
printf(" %02x", out[i]);
|
|
printf("\n");
|
|
}
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
|
|
int nb_sectors, int *pnum)
|
|
{
|
|
uint64_t cluster_offset;
|
|
|
|
*pnum = nb_sectors;
|
|
cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, pnum);
|
|
|
|
return (cluster_offset != 0);
|
|
}
|
|
|
|
/* handle reading after the end of the backing file */
|
|
int qcow2_backing_read1(BlockDriverState *bs,
|
|
int64_t sector_num, uint8_t *buf, int nb_sectors)
|
|
{
|
|
int n1;
|
|
if ((sector_num + nb_sectors) <= bs->total_sectors)
|
|
return nb_sectors;
|
|
if (sector_num >= bs->total_sectors)
|
|
n1 = 0;
|
|
else
|
|
n1 = bs->total_sectors - sector_num;
|
|
memset(buf + n1 * 512, 0, 512 * (nb_sectors - n1));
|
|
return n1;
|
|
}
|
|
|
|
typedef struct QCowAIOCB {
|
|
BlockDriverAIOCB common;
|
|
int64_t sector_num;
|
|
QEMUIOVector *qiov;
|
|
uint8_t *buf;
|
|
void *orig_buf;
|
|
int nb_sectors;
|
|
int n;
|
|
uint64_t cluster_offset;
|
|
uint8_t *cluster_data;
|
|
BlockDriverAIOCB *hd_aiocb;
|
|
struct iovec hd_iov;
|
|
QEMUIOVector hd_qiov;
|
|
QEMUBH *bh;
|
|
QCowL2Meta l2meta;
|
|
} QCowAIOCB;
|
|
|
|
static void qcow_aio_cancel(BlockDriverAIOCB *blockacb)
|
|
{
|
|
QCowAIOCB *acb = (QCowAIOCB *)blockacb;
|
|
if (acb->hd_aiocb)
|
|
bdrv_aio_cancel(acb->hd_aiocb);
|
|
qemu_aio_release(acb);
|
|
}
|
|
|
|
static AIOPool qcow_aio_pool = {
|
|
.aiocb_size = sizeof(QCowAIOCB),
|
|
.cancel = qcow_aio_cancel,
|
|
};
|
|
|
|
static void qcow_aio_read_cb(void *opaque, int ret);
|
|
static void qcow_aio_read_bh(void *opaque)
|
|
{
|
|
QCowAIOCB *acb = opaque;
|
|
qemu_bh_delete(acb->bh);
|
|
acb->bh = NULL;
|
|
qcow_aio_read_cb(opaque, 0);
|
|
}
|
|
|
|
static int qcow_schedule_bh(QEMUBHFunc *cb, QCowAIOCB *acb)
|
|
{
|
|
if (acb->bh)
|
|
return -EIO;
|
|
|
|
acb->bh = qemu_bh_new(cb, acb);
|
|
if (!acb->bh)
|
|
return -EIO;
|
|
|
|
qemu_bh_schedule(acb->bh);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void qcow_aio_read_cb(void *opaque, int ret)
|
|
{
|
|
QCowAIOCB *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster, n1;
|
|
|
|
acb->hd_aiocb = NULL;
|
|
if (ret < 0)
|
|
goto done;
|
|
|
|
/* post process the read buffer */
|
|
if (!acb->cluster_offset) {
|
|
/* nothing to do */
|
|
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
/* nothing to do */
|
|
} else {
|
|
if (s->crypt_method) {
|
|
qcow2_encrypt_sectors(s, acb->sector_num, acb->buf, acb->buf,
|
|
acb->n, 0,
|
|
&s->aes_decrypt_key);
|
|
}
|
|
}
|
|
|
|
acb->nb_sectors -= acb->n;
|
|
acb->sector_num += acb->n;
|
|
acb->buf += acb->n * 512;
|
|
|
|
if (acb->nb_sectors == 0) {
|
|
/* request completed */
|
|
ret = 0;
|
|
goto done;
|
|
}
|
|
|
|
/* prepare next AIO request */
|
|
acb->n = acb->nb_sectors;
|
|
acb->cluster_offset =
|
|
qcow2_get_cluster_offset(bs, acb->sector_num << 9, &acb->n);
|
|
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
|
|
|
if (!acb->cluster_offset) {
|
|
if (bs->backing_hd) {
|
|
/* read from the base image */
|
|
n1 = qcow2_backing_read1(bs->backing_hd, acb->sector_num,
|
|
acb->buf, acb->n);
|
|
if (n1 > 0) {
|
|
acb->hd_iov.iov_base = (void *)acb->buf;
|
|
acb->hd_iov.iov_len = acb->n * 512;
|
|
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
|
acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
|
|
&acb->hd_qiov, acb->n,
|
|
qcow_aio_read_cb, acb);
|
|
if (acb->hd_aiocb == NULL)
|
|
goto done;
|
|
} else {
|
|
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
|
|
if (ret < 0)
|
|
goto done;
|
|
}
|
|
} else {
|
|
/* Note: in this case, no need to wait */
|
|
memset(acb->buf, 0, 512 * acb->n);
|
|
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
|
|
if (ret < 0)
|
|
goto done;
|
|
}
|
|
} else if (acb->cluster_offset & QCOW_OFLAG_COMPRESSED) {
|
|
/* add AIO support for compressed blocks ? */
|
|
if (qcow2_decompress_cluster(s, acb->cluster_offset) < 0)
|
|
goto done;
|
|
memcpy(acb->buf,
|
|
s->cluster_cache + index_in_cluster * 512, 512 * acb->n);
|
|
ret = qcow_schedule_bh(qcow_aio_read_bh, acb);
|
|
if (ret < 0)
|
|
goto done;
|
|
} else {
|
|
if ((acb->cluster_offset & 511) != 0) {
|
|
ret = -EIO;
|
|
goto done;
|
|
}
|
|
|
|
acb->hd_iov.iov_base = (void *)acb->buf;
|
|
acb->hd_iov.iov_len = acb->n * 512;
|
|
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
|
acb->hd_aiocb = bdrv_aio_readv(s->hd,
|
|
(acb->cluster_offset >> 9) + index_in_cluster,
|
|
&acb->hd_qiov, acb->n, qcow_aio_read_cb, acb);
|
|
if (acb->hd_aiocb == NULL)
|
|
goto done;
|
|
}
|
|
|
|
return;
|
|
done:
|
|
if (acb->qiov->niov > 1) {
|
|
qemu_iovec_from_buffer(acb->qiov, acb->orig_buf, acb->qiov->size);
|
|
qemu_vfree(acb->orig_buf);
|
|
}
|
|
acb->common.cb(acb->common.opaque, ret);
|
|
qemu_aio_release(acb);
|
|
}
|
|
|
|
static QCowAIOCB *qcow_aio_setup(BlockDriverState *bs,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb, void *opaque, int is_write)
|
|
{
|
|
QCowAIOCB *acb;
|
|
|
|
acb = qemu_aio_get(&qcow_aio_pool, bs, cb, opaque);
|
|
if (!acb)
|
|
return NULL;
|
|
acb->hd_aiocb = NULL;
|
|
acb->sector_num = sector_num;
|
|
acb->qiov = qiov;
|
|
if (qiov->niov > 1) {
|
|
acb->buf = acb->orig_buf = qemu_blockalign(bs, qiov->size);
|
|
if (is_write)
|
|
qemu_iovec_to_buffer(qiov, acb->buf);
|
|
} else {
|
|
acb->buf = (uint8_t *)qiov->iov->iov_base;
|
|
}
|
|
acb->nb_sectors = nb_sectors;
|
|
acb->n = 0;
|
|
acb->cluster_offset = 0;
|
|
acb->l2meta.nb_clusters = 0;
|
|
return acb;
|
|
}
|
|
|
|
static BlockDriverAIOCB *qcow_aio_readv(BlockDriverState *bs,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb, void *opaque)
|
|
{
|
|
QCowAIOCB *acb;
|
|
|
|
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
|
|
if (!acb)
|
|
return NULL;
|
|
|
|
qcow_aio_read_cb(acb, 0);
|
|
return &acb->common;
|
|
}
|
|
|
|
static void qcow_aio_write_cb(void *opaque, int ret)
|
|
{
|
|
QCowAIOCB *acb = opaque;
|
|
BlockDriverState *bs = acb->common.bs;
|
|
BDRVQcowState *s = bs->opaque;
|
|
int index_in_cluster;
|
|
const uint8_t *src_buf;
|
|
int n_end;
|
|
|
|
acb->hd_aiocb = NULL;
|
|
|
|
if (ret < 0)
|
|
goto done;
|
|
|
|
if (qcow2_alloc_cluster_link_l2(bs, acb->cluster_offset, &acb->l2meta) < 0) {
|
|
qcow2_free_any_clusters(bs, acb->cluster_offset, acb->l2meta.nb_clusters);
|
|
goto done;
|
|
}
|
|
|
|
acb->nb_sectors -= acb->n;
|
|
acb->sector_num += acb->n;
|
|
acb->buf += acb->n * 512;
|
|
|
|
if (acb->nb_sectors == 0) {
|
|
/* request completed */
|
|
ret = 0;
|
|
goto done;
|
|
}
|
|
|
|
index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
|
|
n_end = index_in_cluster + acb->nb_sectors;
|
|
if (s->crypt_method &&
|
|
n_end > QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors)
|
|
n_end = QCOW_MAX_CRYPT_CLUSTERS * s->cluster_sectors;
|
|
|
|
acb->cluster_offset = qcow2_alloc_cluster_offset(bs, acb->sector_num << 9,
|
|
index_in_cluster,
|
|
n_end, &acb->n, &acb->l2meta);
|
|
if (!acb->cluster_offset || (acb->cluster_offset & 511) != 0) {
|
|
ret = -EIO;
|
|
goto done;
|
|
}
|
|
if (s->crypt_method) {
|
|
if (!acb->cluster_data) {
|
|
acb->cluster_data = qemu_mallocz(QCOW_MAX_CRYPT_CLUSTERS *
|
|
s->cluster_size);
|
|
}
|
|
qcow2_encrypt_sectors(s, acb->sector_num, acb->cluster_data, acb->buf,
|
|
acb->n, 1, &s->aes_encrypt_key);
|
|
src_buf = acb->cluster_data;
|
|
} else {
|
|
src_buf = acb->buf;
|
|
}
|
|
acb->hd_iov.iov_base = (void *)src_buf;
|
|
acb->hd_iov.iov_len = acb->n * 512;
|
|
qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
|
|
acb->hd_aiocb = bdrv_aio_writev(s->hd,
|
|
(acb->cluster_offset >> 9) + index_in_cluster,
|
|
&acb->hd_qiov, acb->n,
|
|
qcow_aio_write_cb, acb);
|
|
if (acb->hd_aiocb == NULL)
|
|
goto done;
|
|
|
|
return;
|
|
|
|
done:
|
|
if (acb->qiov->niov > 1)
|
|
qemu_vfree(acb->orig_buf);
|
|
acb->common.cb(acb->common.opaque, ret);
|
|
qemu_aio_release(acb);
|
|
}
|
|
|
|
static BlockDriverAIOCB *qcow_aio_writev(BlockDriverState *bs,
|
|
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
|
|
BlockDriverCompletionFunc *cb, void *opaque)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
QCowAIOCB *acb;
|
|
|
|
s->cluster_cache_offset = -1; /* disable compressed cache */
|
|
|
|
acb = qcow_aio_setup(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
|
|
if (!acb)
|
|
return NULL;
|
|
|
|
qcow_aio_write_cb(acb, 0);
|
|
return &acb->common;
|
|
}
|
|
|
|
static void qcow_close(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
qemu_free(s->l1_table);
|
|
qemu_free(s->l2_cache);
|
|
qemu_free(s->cluster_cache);
|
|
qemu_free(s->cluster_data);
|
|
qcow2_refcount_close(bs);
|
|
bdrv_delete(s->hd);
|
|
}
|
|
|
|
static int get_bits_from_size(size_t size)
|
|
{
|
|
int res = 0;
|
|
|
|
if (size == 0) {
|
|
return -1;
|
|
}
|
|
|
|
while (size != 1) {
|
|
/* Not a power of two */
|
|
if (size & 1) {
|
|
return -1;
|
|
}
|
|
|
|
size >>= 1;
|
|
res++;
|
|
}
|
|
|
|
return res;
|
|
}
|
|
|
|
static int qcow_create2(const char *filename, int64_t total_size,
|
|
const char *backing_file, const char *backing_format,
|
|
int flags, size_t cluster_size)
|
|
{
|
|
|
|
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
|
|
int ref_clusters, backing_format_len = 0;
|
|
QCowHeader header;
|
|
uint64_t tmp, offset;
|
|
QCowCreateState s1, *s = &s1;
|
|
QCowExtension ext_bf = {0, 0};
|
|
|
|
|
|
memset(s, 0, sizeof(*s));
|
|
|
|
fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
|
|
if (fd < 0)
|
|
return -1;
|
|
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 * 512);
|
|
header_size = sizeof(header);
|
|
backing_filename_len = 0;
|
|
if (backing_file) {
|
|
if (backing_format) {
|
|
ext_bf.magic = QCOW_EXT_MAGIC_BACKING_FORMAT;
|
|
backing_format_len = strlen(backing_format);
|
|
ext_bf.len = (backing_format_len + 7) & ~7;
|
|
header_size += ((sizeof(ext_bf) + ext_bf.len + 7) & ~7);
|
|
}
|
|
header.backing_file_offset = cpu_to_be64(header_size);
|
|
backing_filename_len = strlen(backing_file);
|
|
header.backing_file_size = cpu_to_be32(backing_filename_len);
|
|
header_size += backing_filename_len;
|
|
}
|
|
|
|
/* Cluster size */
|
|
s->cluster_bits = get_bits_from_size(cluster_size);
|
|
if (s->cluster_bits < MIN_CLUSTER_BITS ||
|
|
s->cluster_bits > MAX_CLUSTER_BITS)
|
|
{
|
|
fprintf(stderr, "Cluster size must be a power of two between "
|
|
"%d and %dk\n",
|
|
1 << MIN_CLUSTER_BITS,
|
|
1 << (MAX_CLUSTER_BITS - 10));
|
|
return -EINVAL;
|
|
}
|
|
s->cluster_size = 1 << s->cluster_bits;
|
|
|
|
header.cluster_bits = cpu_to_be32(s->cluster_bits);
|
|
header_size = (header_size + 7) & ~7;
|
|
if (flags & BLOCK_FLAG_ENCRYPT) {
|
|
header.crypt_method = cpu_to_be32(QCOW_CRYPT_AES);
|
|
} else {
|
|
header.crypt_method = cpu_to_be32(QCOW_CRYPT_NONE);
|
|
}
|
|
l2_bits = s->cluster_bits - 3;
|
|
shift = s->cluster_bits + l2_bits;
|
|
l1_size = (((total_size * 512) + (1LL << shift) - 1) >> shift);
|
|
offset = align_offset(header_size, s->cluster_size);
|
|
s->l1_table_offset = offset;
|
|
header.l1_table_offset = cpu_to_be64(s->l1_table_offset);
|
|
header.l1_size = cpu_to_be32(l1_size);
|
|
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
|
|
|
|
s->refcount_table = qemu_mallocz(s->cluster_size);
|
|
|
|
s->refcount_table_offset = offset;
|
|
header.refcount_table_offset = cpu_to_be64(offset);
|
|
header.refcount_table_clusters = cpu_to_be32(1);
|
|
offset += s->cluster_size;
|
|
s->refcount_block_offset = offset;
|
|
|
|
/* count how many refcount blocks needed */
|
|
tmp = offset >> s->cluster_bits;
|
|
ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1;
|
|
for (i=0; i < ref_clusters; i++) {
|
|
s->refcount_table[i] = cpu_to_be64(offset);
|
|
offset += s->cluster_size;
|
|
}
|
|
|
|
s->refcount_block = qemu_mallocz(ref_clusters * s->cluster_size);
|
|
|
|
/* update refcounts */
|
|
qcow2_create_refcount_update(s, 0, header_size);
|
|
qcow2_create_refcount_update(s, s->l1_table_offset,
|
|
l1_size * sizeof(uint64_t));
|
|
qcow2_create_refcount_update(s, s->refcount_table_offset, s->cluster_size);
|
|
qcow2_create_refcount_update(s, s->refcount_block_offset,
|
|
ref_clusters * s->cluster_size);
|
|
|
|
/* write all the data */
|
|
write(fd, &header, sizeof(header));
|
|
if (backing_file) {
|
|
if (backing_format_len) {
|
|
char zero[16];
|
|
int d = ext_bf.len - backing_format_len;
|
|
|
|
memset(zero, 0, sizeof(zero));
|
|
cpu_to_be32s(&ext_bf.magic);
|
|
cpu_to_be32s(&ext_bf.len);
|
|
write(fd, &ext_bf, sizeof(ext_bf));
|
|
write(fd, backing_format, backing_format_len);
|
|
if (d>0) {
|
|
write(fd, zero, d);
|
|
}
|
|
}
|
|
write(fd, backing_file, backing_filename_len);
|
|
}
|
|
lseek(fd, s->l1_table_offset, SEEK_SET);
|
|
tmp = 0;
|
|
for(i = 0;i < l1_size; i++) {
|
|
write(fd, &tmp, sizeof(tmp));
|
|
}
|
|
lseek(fd, s->refcount_table_offset, SEEK_SET);
|
|
write(fd, s->refcount_table, s->cluster_size);
|
|
|
|
lseek(fd, s->refcount_block_offset, SEEK_SET);
|
|
write(fd, s->refcount_block, ref_clusters * s->cluster_size);
|
|
|
|
qemu_free(s->refcount_table);
|
|
qemu_free(s->refcount_block);
|
|
close(fd);
|
|
return 0;
|
|
}
|
|
|
|
static int qcow_create(const char *filename, QEMUOptionParameter *options)
|
|
{
|
|
const char *backing_file = NULL;
|
|
const char *backing_fmt = NULL;
|
|
uint64_t sectors = 0;
|
|
int flags = 0;
|
|
size_t cluster_size = 65536;
|
|
|
|
/* Read out options */
|
|
while (options && options->name) {
|
|
if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
|
|
sectors = options->value.n / 512;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FILE)) {
|
|
backing_file = options->value.s;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_BACKING_FMT)) {
|
|
backing_fmt = options->value.s;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_ENCRYPT)) {
|
|
flags |= options->value.n ? BLOCK_FLAG_ENCRYPT : 0;
|
|
} else if (!strcmp(options->name, BLOCK_OPT_CLUSTER_SIZE)) {
|
|
if (options->value.n) {
|
|
cluster_size = options->value.n;
|
|
}
|
|
}
|
|
options++;
|
|
}
|
|
|
|
return qcow_create2(filename, sectors, backing_file, backing_fmt, flags,
|
|
cluster_size);
|
|
}
|
|
|
|
static int qcow_make_empty(BlockDriverState *bs)
|
|
{
|
|
#if 0
|
|
/* XXX: not correct */
|
|
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(s->hd, s->l1_table_offset, s->l1_table, l1_length) < 0)
|
|
return -1;
|
|
ret = bdrv_truncate(s->hd, s->l1_table_offset + l1_length);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
l2_cache_reset(bs);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/* XXX: put compressed sectors first, then all the cluster aligned
|
|
tables to avoid losing bytes in alignment */
|
|
static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
|
|
const uint8_t *buf, int nb_sectors)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
z_stream strm;
|
|
int ret, out_len;
|
|
uint8_t *out_buf;
|
|
uint64_t cluster_offset;
|
|
|
|
if (nb_sectors == 0) {
|
|
/* align end of file to a sector boundary to ease reading with
|
|
sector based I/Os */
|
|
cluster_offset = bdrv_getlength(s->hd);
|
|
cluster_offset = (cluster_offset + 511) & ~511;
|
|
bdrv_truncate(s->hd, cluster_offset);
|
|
return 0;
|
|
}
|
|
|
|
if (nb_sectors != s->cluster_sectors)
|
|
return -EINVAL;
|
|
|
|
out_buf = qemu_malloc(s->cluster_size + (s->cluster_size / 1000) + 128);
|
|
|
|
/* 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) {
|
|
qemu_free(out_buf);
|
|
return -1;
|
|
}
|
|
|
|
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) {
|
|
qemu_free(out_buf);
|
|
deflateEnd(&strm);
|
|
return -1;
|
|
}
|
|
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 */
|
|
bdrv_write(bs, sector_num, buf, s->cluster_sectors);
|
|
} else {
|
|
cluster_offset = qcow2_alloc_compressed_cluster_offset(bs,
|
|
sector_num << 9, out_len);
|
|
if (!cluster_offset)
|
|
return -1;
|
|
cluster_offset &= s->cluster_offset_mask;
|
|
if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
|
|
qemu_free(out_buf);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
qemu_free(out_buf);
|
|
return 0;
|
|
}
|
|
|
|
static void qcow_flush(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
bdrv_flush(s->hd);
|
|
}
|
|
|
|
static int64_t qcow_vm_state_offset(BDRVQcowState *s)
|
|
{
|
|
return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
|
|
}
|
|
|
|
static int qcow_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
bdi->cluster_size = s->cluster_size;
|
|
bdi->vm_state_offset = qcow_vm_state_offset(s);
|
|
return 0;
|
|
}
|
|
|
|
|
|
static int qcow_check(BlockDriverState *bs)
|
|
{
|
|
return qcow2_check_refcounts(bs);
|
|
}
|
|
|
|
#if 0
|
|
static void dump_refcounts(BlockDriverState *bs)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int64_t nb_clusters, k, k1, size;
|
|
int refcount;
|
|
|
|
size = bdrv_getlength(s->hd);
|
|
nb_clusters = size_to_clusters(s, size);
|
|
for(k = 0; k < nb_clusters;) {
|
|
k1 = k;
|
|
refcount = get_refcount(bs, k);
|
|
k++;
|
|
while (k < nb_clusters && get_refcount(bs, k) == refcount)
|
|
k++;
|
|
printf("%lld: refcount=%d nb=%lld\n", k, refcount, k - k1);
|
|
}
|
|
}
|
|
#endif
|
|
|
|
static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
|
|
int64_t pos, int size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int growable = bs->growable;
|
|
|
|
bs->growable = 1;
|
|
bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size);
|
|
bs->growable = growable;
|
|
|
|
return size;
|
|
}
|
|
|
|
static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf,
|
|
int64_t pos, int size)
|
|
{
|
|
BDRVQcowState *s = bs->opaque;
|
|
int growable = bs->growable;
|
|
int ret;
|
|
|
|
bs->growable = 1;
|
|
ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size);
|
|
bs->growable = growable;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static QEMUOptionParameter qcow_create_options[] = {
|
|
{
|
|
.name = BLOCK_OPT_SIZE,
|
|
.type = OPT_SIZE,
|
|
.help = "Virtual disk size"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_BACKING_FILE,
|
|
.type = OPT_STRING,
|
|
.help = "File name of a base image"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_BACKING_FMT,
|
|
.type = OPT_STRING,
|
|
.help = "Image format of the base image"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_ENCRYPT,
|
|
.type = OPT_FLAG,
|
|
.help = "Encrypt the image"
|
|
},
|
|
{
|
|
.name = BLOCK_OPT_CLUSTER_SIZE,
|
|
.type = OPT_SIZE,
|
|
.help = "qcow2 cluster size"
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
static BlockDriver bdrv_qcow2 = {
|
|
.format_name = "qcow2",
|
|
.instance_size = sizeof(BDRVQcowState),
|
|
.bdrv_probe = qcow_probe,
|
|
.bdrv_open = qcow_open,
|
|
.bdrv_close = qcow_close,
|
|
.bdrv_create = qcow_create,
|
|
.bdrv_flush = qcow_flush,
|
|
.bdrv_is_allocated = qcow_is_allocated,
|
|
.bdrv_set_key = qcow_set_key,
|
|
.bdrv_make_empty = qcow_make_empty,
|
|
|
|
.bdrv_aio_readv = qcow_aio_readv,
|
|
.bdrv_aio_writev = qcow_aio_writev,
|
|
.bdrv_write_compressed = qcow_write_compressed,
|
|
|
|
.bdrv_snapshot_create = qcow2_snapshot_create,
|
|
.bdrv_snapshot_goto = qcow2_snapshot_goto,
|
|
.bdrv_snapshot_delete = qcow2_snapshot_delete,
|
|
.bdrv_snapshot_list = qcow2_snapshot_list,
|
|
.bdrv_get_info = qcow_get_info,
|
|
|
|
.bdrv_save_vmstate = qcow_save_vmstate,
|
|
.bdrv_load_vmstate = qcow_load_vmstate,
|
|
|
|
.create_options = qcow_create_options,
|
|
.bdrv_check = qcow_check,
|
|
};
|
|
|
|
static void bdrv_qcow2_init(void)
|
|
{
|
|
bdrv_register(&bdrv_qcow2);
|
|
}
|
|
|
|
block_init(bdrv_qcow2_init);
|