Merge remote branch 'kwolf/for-anthony' into staging

12 files changed, 414 insertions, 118 deletions

diff --git a/block.c b/block.c
index 67f099878a..39724c17d3 100644
--- a/block.c
+++ b/block.c
@@ -56,7 +56,6 @@ static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
                         uint8_t *buf, int nb_sectors);
 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
                          const uint8_t *buf, int nb_sectors);
-static BlockDriver *find_protocol(const char *filename);
 
 static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
     QTAILQ_HEAD_INITIALIZER(bdrv_states);
@@ -210,7 +209,7 @@ int bdrv_create_file(const char* filename, QEMUOptionParameter *options)
 {
     BlockDriver *drv;
 
-    drv = find_protocol(filename);
+    drv = bdrv_find_protocol(filename);
     if (drv == NULL) {
         drv = bdrv_find_format("file");
     }
@@ -283,7 +282,7 @@ static BlockDriver *find_hdev_driver(const char *filename)
     return drv;
 }
 
-static BlockDriver *find_protocol(const char *filename)
+BlockDriver *bdrv_find_protocol(const char *filename)
 {
     BlockDriver *drv1;
     char protocol[128];
@@ -333,8 +332,10 @@ static BlockDriver *find_image_format(const char *filename)
         return NULL;
 
     /* Return the raw BlockDriver * to scsi-generic devices */
-    if (bs->sg)
+    if (bs->sg) {
+        bdrv_delete(bs);
         return bdrv_find_format("raw");
+    }
 
     ret = bdrv_pread(bs, 0, buf, sizeof(buf));
     bdrv_delete(bs);
@@ -478,7 +479,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
     BlockDriver *drv;
     int ret;
 
-    drv = find_protocol(filename);
+    drv = bdrv_find_protocol(filename);
     if (!drv) {
         return -ENOENT;
     }
@@ -1950,7 +1951,7 @@ static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
             // Add the second request
             qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
 
-            reqs[outidx].nb_sectors += reqs[i].nb_sectors;
+            reqs[outidx].nb_sectors = qiov->size >> 9;
             reqs[outidx].qiov = qiov;
 
             mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
diff --git a/block.h b/block.h
index 24efeb68b1..756670d22f 100644
--- a/block.h
+++ b/block.h
@@ -38,7 +38,7 @@ typedef struct QEMUSnapshotInfo {
 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB)
 
 #define BDRV_SECTOR_BITS   9
-#define BDRV_SECTOR_SIZE   (1 << BDRV_SECTOR_BITS)
+#define BDRV_SECTOR_SIZE   (1ULL << BDRV_SECTOR_BITS)
 #define BDRV_SECTOR_MASK   ~(BDRV_SECTOR_SIZE - 1)
 
 typedef enum {
@@ -54,6 +54,7 @@ void bdrv_info_stats(Monitor *mon, QObject **ret_data);
 
 void bdrv_init(void);
 void bdrv_init_with_whitelist(void);
+BlockDriver *bdrv_find_protocol(const char *filename);
 BlockDriver *bdrv_find_format(const char *format_name);
 BlockDriver *bdrv_find_whitelisted_format(const char *format_name);
 int bdrv_create(BlockDriver *drv, const char* filename,
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index c11680d12a..03a9f25799 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -157,31 +157,36 @@ static uint64_t *seek_l2_table(BDRVQcowState *s, uint64_t l2_offset)
  * the image file failed.
  */
 
-static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
+static int l2_load(BlockDriverState *bs, uint64_t l2_offset,
+    uint64_t **l2_table)
 {
     BDRVQcowState *s = bs->opaque;
     int min_index;
-    uint64_t *l2_table;
+    int ret;
 
     /* seek if the table for the given offset is in the cache */
 
-    l2_table = seek_l2_table(s, l2_offset);
-    if (l2_table != NULL)
-        return l2_table;
+    *l2_table = seek_l2_table(s, l2_offset);
+    if (*l2_table != NULL) {
+        return 0;
+    }
 
     /* not found: load a new entry in the least used one */
 
     min_index = l2_cache_new_entry(bs);
-    l2_table = s->l2_cache + (min_index << s->l2_bits);
+    *l2_table = s->l2_cache + (min_index << s->l2_bits);
 
     BLKDBG_EVENT(bs->file, BLKDBG_L2_LOAD);
-    if (bdrv_pread(bs->file, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) !=
-        s->l2_size * sizeof(uint64_t))
-        return NULL;
+    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;
 
-    return l2_table;
+    return 0;
 }
 
 /*
@@ -239,14 +244,6 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
         return l2_offset;
     }
 
-    /* update the L1 entry */
-
-    s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED;
-    ret = write_l1_entry(bs, l1_index);
-    if (ret < 0) {
-        return ret;
-    }
-
     /* allocate a new entry in the l2 cache */
 
     min_index = l2_cache_new_entry(bs);
@@ -261,7 +258,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
         ret = bdrv_pread(bs->file, old_l2_offset, l2_table,
             s->l2_size * sizeof(uint64_t));
         if (ret < 0) {
-            return ret;
+            goto fail;
         }
     }
     /* write the l2 table to the file */
@@ -269,7 +266,14 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
     ret = bdrv_pwrite(bs->file, l2_offset, l2_table,
         s->l2_size * sizeof(uint64_t));
     if (ret < 0) {
-        return ret;
+        goto fail;
+    }
+
+    /* update the L1 entry */
+    s->l1_table[l1_index] = l2_offset | QCOW_OFLAG_COPIED;
+    ret = write_l1_entry(bs, l1_index);
+    if (ret < 0) {
+        goto fail;
     }
 
     /* update the l2 cache entry */
@@ -279,6 +283,10 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
 
     *table = l2_table;
     return 0;
+
+fail:
+    qcow2_l2_cache_reset(bs);
+    return ret;
 }
 
 static int count_contiguous_clusters(uint64_t nb_clusters, int cluster_size,
@@ -342,7 +350,13 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num,
 
     while (nb_sectors > 0) {
         n = nb_sectors;
-        cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, &n);
+
+        ret = qcow2_get_cluster_offset(bs, sector_num << 9, &n,
+            &cluster_offset);
+        if (ret < 0) {
+            return ret;
+        }
+
         index_in_cluster = sector_num & (s->cluster_sectors - 1);
         if (!cluster_offset) {
             if (bs->backing_hd) {
@@ -409,28 +423,29 @@ static int copy_sectors(BlockDriverState *bs, uint64_t start_sect,
 /*
  * get_cluster_offset
  *
- * For a given offset of the disk image, return cluster offset in
- * qcow2 file.
+ * For a given offset of the disk image, find the cluster offset in
+ * qcow2 file. The offset is stored in *cluster_offset.
  *
  * on entry, *num is the number of contiguous clusters we'd like to
  * access following offset.
  *
  * on exit, *num is the number of contiguous clusters we can read.
  *
- * Return 1, if the offset is found
- * Return 0, otherwise.
+ * Return 0, if the offset is found
+ * Return -errno, otherwise.
  *
  */
 
-uint64_t qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
-    int *num)
+int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
+    int *num, uint64_t *cluster_offset)
 {
     BDRVQcowState *s = bs->opaque;
     unsigned int l1_index, l2_index;
-    uint64_t l2_offset, *l2_table, cluster_offset;
+    uint64_t l2_offset, *l2_table;
     int l1_bits, c;
     unsigned int index_in_cluster, nb_clusters;
     uint64_t nb_available, nb_needed;
+    int ret;
 
     index_in_cluster = (offset >> 9) & (s->cluster_sectors - 1);
     nb_needed = *num + index_in_cluster;
@@ -451,7 +466,7 @@ uint64_t qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
         nb_needed = nb_available;
     }
 
-    cluster_offset = 0;
+    *cluster_offset = 0;
 
     /* seek the the l2 offset in the l1 table */
 
@@ -469,17 +484,18 @@ uint64_t qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
     /* load the l2 table in memory */
 
     l2_offset &= ~QCOW_OFLAG_COPIED;
-    l2_table = l2_load(bs, l2_offset);
-    if (l2_table == NULL)
-        return 0;
+    ret = l2_load(bs, l2_offset, &l2_table);
+    if (ret < 0) {
+        return ret;
+    }
 
     /* find the cluster offset for the given disk offset */
 
     l2_index = (offset >> s->cluster_bits) & (s->l2_size - 1);
-    cluster_offset = be64_to_cpu(l2_table[l2_index]);
+    *cluster_offset = be64_to_cpu(l2_table[l2_index]);
     nb_clusters = size_to_clusters(s, nb_needed << 9);
 
-    if (!cluster_offset) {
+    if (!*cluster_offset) {
         /* how many empty clusters ? */
         c = count_contiguous_free_clusters(nb_clusters, &l2_table[l2_index]);
     } else {
@@ -495,7 +511,8 @@ out:
 
     *num = nb_available - index_in_cluster;
 
-    return cluster_offset & ~QCOW_OFLAG_COPIED;
+    *cluster_offset &=~QCOW_OFLAG_COPIED;
+    return 0;
 }
 
 /*
@@ -536,9 +553,9 @@ static int get_cluster_table(BlockDriverState *bs, uint64_t offset,
     if (l2_offset & QCOW_OFLAG_COPIED) {
         /* load the l2 table in memory */
         l2_offset &= ~QCOW_OFLAG_COPIED;
-        l2_table = l2_load(bs, l2_offset);
-        if (l2_table == NULL) {
-            return -EIO;
+        ret = l2_load(bs, l2_offset, &l2_table);
+        if (ret < 0) {
+            return ret;
         }
     } else {
         if (l2_offset)
@@ -696,6 +713,7 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
 
     ret = write_l2_entries(bs, l2_table, l2_offset, l2_index, m->nb_clusters);
     if (ret < 0) {
+        qcow2_l2_cache_reset(bs);
         goto err;
     }
 
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 744107cd1d..22b0b45ff7 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -221,8 +221,6 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
 
     /* Allocate the refcount block itself and mark it as used */
     uint64_t new_block = alloc_clusters_noref(bs, s->cluster_size);
-    memset(s->refcount_block_cache, 0, s->cluster_size);
-    s->refcount_block_cache_offset = new_block;
 
 #ifdef DEBUG_ALLOC2
     fprintf(stderr, "qcow2: Allocate refcount block %d for %" PRIx64
@@ -231,6 +229,10 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
 #endif
 
     if (in_same_refcount_block(s, new_block, cluster_index << s->cluster_bits)) {
+        /* Zero the new refcount block before updating it */
+        memset(s->refcount_block_cache, 0, s->cluster_size);
+        s->refcount_block_cache_offset = new_block;
+
         /* The block describes itself, need to update the cache */
         int block_index = (new_block >> s->cluster_bits) &
             ((1 << (s->cluster_bits - REFCOUNT_SHIFT)) - 1);
@@ -242,6 +244,11 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
         if (ret < 0) {
             goto fail_block;
         }
+
+        /* Initialize the new refcount block only after updating its refcount,
+         * update_refcount uses the refcount cache itself */
+        memset(s->refcount_block_cache, 0, s->cluster_size);
+        s->refcount_block_cache_offset = new_block;
     }
 
     /* Now the new refcount block needs to be written to disk */
@@ -404,22 +411,28 @@ static int write_refcount_block_entries(BlockDriverState *bs,
 {
     BDRVQcowState *s = bs->opaque;
     size_t size;
+    int ret;
 
     if (cache_refcount_updates) {
         return 0;
     }
 
+    if (first_index < 0) {
+        return 0;
+    }
+
     first_index &= ~(REFCOUNTS_PER_SECTOR - 1);
     last_index = (last_index + REFCOUNTS_PER_SECTOR)
         & ~(REFCOUNTS_PER_SECTOR - 1);
 
     size = (last_index - first_index) << REFCOUNT_SHIFT;
+
     BLKDBG_EVENT(bs->file, BLKDBG_REFBLOCK_UPDATE_PART);
-    if (bdrv_pwrite(bs->file,
+    ret = bdrv_pwrite(bs->file,
         refcount_block_offset + (first_index << REFCOUNT_SHIFT),
-        &s->refcount_block_cache[first_index], size) != size)
-    {
-        return -EIO;
+        &s->refcount_block_cache[first_index], size);
+    if (ret < 0) {
+        return ret;
     }
 
     return 0;
@@ -460,10 +473,10 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
         table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
         if ((old_table_index >= 0) && (table_index != old_table_index)) {
 
-            if (write_refcount_block_entries(bs, refcount_block_offset,
-                first_index, last_index) < 0)
-            {
-                return -EIO;
+            ret = write_refcount_block_entries(bs, refcount_block_offset,
+                first_index, last_index);
+            if (ret < 0) {
+                return ret;
             }
 
             first_index = -1;
@@ -505,10 +518,11 @@ fail:
 
     /* Write last changed block to disk */
     if (refcount_block_offset != 0) {
-        if (write_refcount_block_entries(bs, refcount_block_offset,
-            first_index, last_index) < 0)
-        {
-            return ret < 0 ? ret : -EIO;
+        int wret;
+        wret = write_refcount_block_entries(bs, refcount_block_offset,
+            first_index, last_index);
+        if (wret < 0) {
+            return ret < 0 ? ret : wret;
         }
     }
 
diff --git a/block/qcow2.c b/block/qcow2.c
index 5b72758915..33fa9a9012 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -297,9 +297,15 @@ static int qcow_is_allocated(BlockDriverState *bs, int64_t sector_num,
                              int nb_sectors, int *pnum)
 {
     uint64_t cluster_offset;
+    int ret;
 
     *pnum = nb_sectors;
-    cluster_offset = qcow2_get_cluster_offset(bs, sector_num << 9, pnum);
+    /* FIXME We can get errors here, but the bdrv_is_allocated interface can't
+     * pass them on today */
+    ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
+    if (ret < 0) {
+        *pnum = 0;
+    }
 
     return (cluster_offset != 0);
 }
@@ -409,8 +415,12 @@ static void qcow_aio_read_cb(void *opaque, int ret)
 
     /* prepare next AIO request */
     acb->cur_nr_sectors = acb->remaining_sectors;
-    acb->cluster_offset = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
-                                                   &acb->cur_nr_sectors);
+    ret = qcow2_get_cluster_offset(bs, acb->sector_num << 9,
+        &acb->cur_nr_sectors, &acb->cluster_offset);
+    if (ret < 0) {
+        goto done;
+    }
+
     index_in_cluster = acb->sector_num & (s->cluster_sectors - 1);
 
     if (!acb->cluster_offset) {
diff --git a/block/qcow2.h b/block/qcow2.h
index 01053b79d9..c59b827da8 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -196,8 +196,8 @@ void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
                      int nb_sectors, int enc,
                      const AES_KEY *key);
 
-uint64_t qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
-    int *num);
+int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
+    int *num, uint64_t *cluster_offset);
 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
     int n_start, int n_end, int *num, QCowL2Meta *m);
 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index b43c5315a8..a67ffe3113 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -35,7 +35,7 @@ struct qemu_paiocb {
     int aio_fildes;
     union {
         struct iovec *aio_iov;
-	void *aio_ioctl_buf;
+        void *aio_ioctl_buf;
     };
     int aio_niov;
     size_t aio_nbytes;
@@ -119,21 +119,21 @@ static void thread_create(pthread_t *thread, pthread_attr_t *attr,
 
 static ssize_t handle_aiocb_ioctl(struct qemu_paiocb *aiocb)
 {
-	int ret;
-
-	ret = ioctl(aiocb->aio_fildes, aiocb->aio_ioctl_cmd, aiocb->aio_ioctl_buf);
-	if (ret == -1)
-		return -errno;
-
-	/*
-	 * This looks weird, but the aio code only consideres a request
-	 * successfull if it has written the number full number of bytes.
-	 *
-	 * Now we overload aio_nbytes as aio_ioctl_cmd for the ioctl command,
-	 * so in fact we return the ioctl command here to make posix_aio_read()
-	 * happy..
-	 */
-	return aiocb->aio_nbytes;
+    int ret;
+
+    ret = ioctl(aiocb->aio_fildes, aiocb->aio_ioctl_cmd, aiocb->aio_ioctl_buf);
+    if (ret == -1)
+        return -errno;
+
+    /*
+     * This looks weird, but the aio code only consideres a request
+     * successfull if it has written the number full number of bytes.
+     *
+     * Now we overload aio_nbytes as aio_ioctl_cmd for the ioctl command,
+     * so in fact we return the ioctl command here to make posix_aio_read()
+     * happy..
+     */
+    return aiocb->aio_nbytes;
 }
 
 static ssize_t handle_aiocb_flush(struct qemu_paiocb *aiocb)
@@ -249,10 +249,10 @@ static ssize_t handle_aiocb_rw(struct qemu_paiocb *aiocb)
          * Try preadv/pwritev first and fall back to linearizing the
          * buffer if it's not supported.
          */
-	if (preadv_present) {
+        if (preadv_present) {
             nbytes = handle_aiocb_rw_vector(aiocb);
             if (nbytes == aiocb->aio_nbytes)
-	        return nbytes;
+                return nbytes;
             if (nbytes < 0 && nbytes != -ENOSYS)
                 return nbytes;
             preadv_present = 0;
@@ -335,19 +335,19 @@ static void *aio_thread(void *unused)
         switch (aiocb->aio_type & QEMU_AIO_TYPE_MASK) {
         case QEMU_AIO_READ:
         case QEMU_AIO_WRITE:
-		ret = handle_aiocb_rw(aiocb);
-		break;
+            ret = handle_aiocb_rw(aiocb);
+            break;
         case QEMU_AIO_FLUSH:
-                ret = handle_aiocb_flush(aiocb);
-                break;
+            ret = handle_aiocb_flush(aiocb);
+            break;
         case QEMU_AIO_IOCTL:
-		ret = handle_aiocb_ioctl(aiocb);
-		break;
-	default:
-		fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
-		ret = -EINVAL;
-		break;
-	}
+            ret = handle_aiocb_ioctl(aiocb);
+            break;
+        default:
+            fprintf(stderr, "invalid aio request (0x%x)\n", aiocb->aio_type);
+            ret = -EINVAL;
+            break;
+        }
 
         mutex_lock(&lock);
         aiocb->ret = ret;
diff --git a/qemu-img.c b/qemu-img.c
index cb007b757d..ea091f00ca 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -252,8 +252,8 @@ static int img_create(int argc, char **argv)
     const char *base_fmt = NULL;
     const char *filename;
     const char *base_filename = NULL;
-    BlockDriver *drv;
-    QEMUOptionParameter *param = NULL;
+    BlockDriver *drv, *proto_drv;
+    QEMUOptionParameter *param = NULL, *create_options = NULL;
     char *options = NULL;
 
     flags = 0;
@@ -286,33 +286,42 @@ static int img_create(int argc, char **argv)
         }
     }
 
+    /* Get the filename */
+    if (optind >= argc)
+        help();
+    filename = argv[optind++];
+
     /* Find driver and parse its options */
     drv = bdrv_find_format(fmt);
     if (!drv)
         error("Unknown file format '%s'", fmt);
 
+    proto_drv = bdrv_find_protocol(filename);
+    if (!proto_drv)
+        error("Unknown protocol '%s'", filename);
+
+    create_options = append_option_parameters(create_options,
+                                              drv->create_options);
+    create_options = append_option_parameters(create_options,
+                                              proto_drv->create_options);
+
     if (options && !strcmp(options, "?")) {
-        print_option_help(drv->create_options);
+        print_option_help(create_options);
         return 0;
     }
 
     /* Create parameter list with default values */
-    param = parse_option_parameters("", drv->create_options, param);
+    param = parse_option_parameters("", create_options, param);
     set_option_parameter_int(param, BLOCK_OPT_SIZE, -1);
 
     /* Parse -o options */
     if (options) {
-        param = parse_option_parameters(options, drv->create_options, param);
+        param = parse_option_parameters(options, create_options, param);
         if (param == NULL) {
             error("Invalid options for file format '%s'.", fmt);
         }
     }
 
-    /* Get the filename */
-    if (optind >= argc)
-        help();
-    filename = argv[optind++];
-
     /* Add size to parameters */
     if (optind < argc) {
         set_option_parameter(param, BLOCK_OPT_SIZE, argv[optind++]);
@@ -362,6 +371,7 @@ static int img_create(int argc, char **argv)
     puts("");
 
     ret = bdrv_create(drv, filename, param);
+    free_option_parameters(create_options);
     free_option_parameters(param);
 
     if (ret < 0) {
@@ -543,14 +553,14 @@ static int img_convert(int argc, char **argv)
 {
     int c, ret, n, n1, bs_n, bs_i, flags, cluster_size, cluster_sectors;
     const char *fmt, *out_fmt, *out_baseimg, *out_filename;
-    BlockDriver *drv;
+    BlockDriver *drv, *proto_drv;
     BlockDriverState **bs, *out_bs;
     int64_t total_sectors, nb_sectors, sector_num, bs_offset;
     uint64_t bs_sectors;
     uint8_t * buf;
     const uint8_t *buf1;
     BlockDriverInfo bdi;
-    QEMUOptionParameter *param = NULL;
+    QEMUOptionParameter *param = NULL, *create_options = NULL;
     char *options = NULL;
 
     fmt = NULL;
@@ -615,19 +625,27 @@ static int img_convert(int argc, char **argv)
     if (!drv)
         error("Unknown file format '%s'", out_fmt);
 
+    proto_drv = bdrv_find_protocol(out_filename);
+    if (!proto_drv)
+        error("Unknown protocol '%s'", out_filename);
+
+    create_options = append_option_parameters(create_options,
+                                              drv->create_options);
+    create_options = append_option_parameters(create_options,
+                                              proto_drv->create_options);
     if (options && !strcmp(options, "?")) {
-        print_option_help(drv->create_options);
+        print_option_help(create_options);
         free(bs);
         return 0;
     }
 
     if (options) {
-        param = parse_option_parameters(options, drv->create_options, param);
+        param = parse_option_parameters(options, create_options, param);
         if (param == NULL) {
             error("Invalid options for file format '%s'.", out_fmt);
         }
     } else {
-        param = parse_option_parameters("", drv->create_options, param);
+        param = parse_option_parameters("", create_options, param);
     }
 
     set_option_parameter_int(param, BLOCK_OPT_SIZE, total_sectors * 512);
@@ -649,6 +667,7 @@ static int img_convert(int argc, char **argv)
 
     /* Create the new image */
     ret = bdrv_create(drv, out_filename, param);
+    free_option_parameters(create_options);
     free_option_parameters(param);
 
     if (ret < 0) {
diff --git a/qemu-io.c b/qemu-io.c
index f39109e231..72a45247da 100644
--- a/qemu-io.c
+++ b/qemu-io.c
@@ -267,6 +267,47 @@ static int do_aio_writev(QEMUIOVector *qiov, int64_t offset, int *total)
 	return async_ret < 0 ? async_ret : 1;
 }
 
+struct multiwrite_async_ret {
+	int num_done;
+	int error;
+};
+
+static void multiwrite_cb(void *opaque, int ret)
+{
+	struct multiwrite_async_ret *async_ret = opaque;
+
+	async_ret->num_done++;
+	if (ret < 0) {
+		async_ret->error = ret;
+	}
+}
+
+static int do_aio_multiwrite(BlockRequest* reqs, int num_reqs, int *total)
+{
+	int i, ret;
+	struct multiwrite_async_ret async_ret = {
+		.num_done = 0,
+		.error = 0,
+	};
+
+	*total = 0;
+	for (i = 0; i < num_reqs; i++) {
+		reqs[i].cb = multiwrite_cb;
+		reqs[i].opaque = &async_ret;
+		*total += reqs[i].qiov->size;
+	}
+
+	ret = bdrv_aio_multiwrite(bs, reqs, num_reqs);
+	if (ret < 0) {
+		return ret;
+	}
+
+	while (async_ret.num_done < num_reqs) {
+		qemu_aio_wait();
+	}
+
+	return async_ret.error < 0 ? async_ret.error : 1;
+}
 
 static void
 read_help(void)
@@ -811,6 +852,156 @@ out:
 	return 0;
 }
 
+static void
+multiwrite_help(void)
+{
+	printf(
+"\n"
+" writes a range of bytes from the given offset source from multiple buffers,\n"
+" in a batch of requests that may be merged by qemu\n"
+"\n"
+" Example:\n"
+" 'multiwrite 512 1k 1k ; 4k 1k' \n"
+"  writes 2 kB at 512 bytes and 1 kB at 4 kB into the open file\n"
+"\n"
+" Writes into a segment of the currently open file, using a buffer\n"
+" filled with a set pattern (0xcdcdcdcd). The pattern byte is increased\n"
+" by one for each request contained in the multiwrite command.\n"
+" -P, -- use different pattern to fill file\n"
+" -C, -- report statistics in a machine parsable format\n"
+" -q, -- quiet mode, do not show I/O statistics\n"
+"\n");
+}
+
+static int multiwrite_f(int argc, char **argv);
+
+static const cmdinfo_t multiwrite_cmd = {
+	.name		= "multiwrite",
+	.cfunc		= multiwrite_f,
+	.argmin		= 2,
+	.argmax		= -1,
+	.args		= "[-Cq] [-P pattern ] off len [len..] [; off len [len..]..]",
+	.oneline	= "issues multiple write requests at once",
+	.help		= multiwrite_help,
+};
+
+static int
+multiwrite_f(int argc, char **argv)
+{
+	struct timeval t1, t2;
+	int Cflag = 0, qflag = 0;
+	int c, cnt;
+	char **buf;
+	int64_t offset, first_offset = 0;
+	/* Some compilers get confused and warn if this is not initialized.  */
+	int total = 0;
+	int nr_iov;
+	int nr_reqs;
+	int pattern = 0xcd;
+	QEMUIOVector *qiovs;
+	int i;
+	BlockRequest *reqs;
+
+	while ((c = getopt(argc, argv, "CqP:")) != EOF) {
+		switch (c) {
+		case 'C':
+			Cflag = 1;
+			break;
+		case 'q':
+			qflag = 1;
+			break;
+		case 'P':
+			pattern = parse_pattern(optarg);
+			if (pattern < 0)
+				return 0;
+			break;
+		default:
+			return command_usage(&writev_cmd);
+		}
+	}
+
+	if (optind > argc - 2)
+		return command_usage(&writev_cmd);
+
+	nr_reqs = 1;
+	for (i = optind; i < argc; i++) {
+		if (!strcmp(argv[i], ";")) {
+			nr_reqs++;
+		}
+	}
+
+	reqs = qemu_malloc(nr_reqs * sizeof(*reqs));
+	buf = qemu_malloc(nr_reqs * sizeof(*buf));
+	qiovs = qemu_malloc(nr_reqs * sizeof(*qiovs));
+
+	for (i = 0; i < nr_reqs; i++) {
+		int j;
+
+		/* Read the offset of the request */
+		offset = cvtnum(argv[optind]);
+		if (offset < 0) {
+			printf("non-numeric offset argument -- %s\n", argv[optind]);
+			return 0;
+		}
+		optind++;
+
+		if (offset & 0x1ff) {
+			printf("offset %lld is not sector aligned\n",
+				(long long)offset);
+			return 0;
+		}
+
+        if (i == 0) {
+            first_offset = offset;
+        }
+
+		/* Read lengths for qiov entries */
+		for (j = optind; j < argc; j++) {
+			if (!strcmp(argv[j], ";")) {
+				break;
+			}
+		}
+
+		nr_iov = j - optind;
+
+		/* Build request */
+		reqs[i].qiov = &qiovs[i];
+		buf[i] = create_iovec(reqs[i].qiov, &argv[optind], nr_iov, pattern);
+		reqs[i].sector = offset >> 9;
+		reqs[i].nb_sectors = reqs[i].qiov->size >> 9;
+
+		optind = j + 1;
+
+		offset += reqs[i].qiov->size;
+		pattern++;
+	}
+
+	gettimeofday(&t1, NULL);
+	cnt = do_aio_multiwrite(reqs, nr_reqs, &total);
+	gettimeofday(&t2, NULL);
+
+	if (cnt < 0) {
+		printf("aio_multiwrite failed: %s\n", strerror(-cnt));
+		goto out;
+	}
+
+	if (qflag)
+		goto out;
+
+	/* Finally, report back -- -C gives a parsable format */
+	t2 = tsub(t2, t1);
+	print_report("wrote", &t2, first_offset, total, total, cnt, Cflag);
+out:
+	for (i = 0; i < nr_reqs; i++) {
+		qemu_io_free(buf[i]);
+		qemu_iovec_destroy(&qiovs[i]);
+	}
+	qemu_free(buf);
+	qemu_free(reqs);
+	qemu_free(qiovs);
+	return 0;
+}
+
 struct aio_ctx {
 	QEMUIOVector qiov;
 	int64_t offset;
@@ -1483,6 +1674,7 @@ int main(int argc, char **argv)
 	add_command(&readv_cmd);
 	add_command(&write_cmd);
 	add_command(&writev_cmd);
+	add_command(&multiwrite_cmd);
 	add_command(&aio_read_cmd);
 	add_command(&aio_write_cmd);
 	add_command(&aio_flush_cmd);
diff --git a/qemu-option.c b/qemu-option.c
index 076dddfc02..acd74f9124 100644
--- a/qemu-option.c
+++ b/qemu-option.c
@@ -346,6 +346,51 @@ void free_option_parameters(QEMUOptionParameter *list)
 }
 
 /*
+ * Count valid options in list
+ */
+static size_t count_option_parameters(QEMUOptionParameter *list)
+{
+    size_t num_options = 0;
+
+    while (list && list->name) {
+        num_options++;
+        list++;
+    }
+
+    return num_options;
+}
+
+/*
+ * Append an option list (list) to an option list (dest).
+ *
+ * If dest is NULL, a new copy of list is created.
+ *
+ * Returns a pointer to the first element of dest (or the newly allocated copy)
+ */
+QEMUOptionParameter *append_option_parameters(QEMUOptionParameter *dest,
+    QEMUOptionParameter *list)
+{
+    size_t num_options, num_dest_options;
+
+    num_options = count_option_parameters(dest);
+    num_dest_options = num_options;
+
+    num_options += count_option_parameters(list);
+
+    dest = qemu_realloc(dest, (num_options + 1) * sizeof(QEMUOptionParameter));
+
+    while (list && list->name) {
+        if (get_option_parameter(dest, list->name) == NULL) {
+            dest[num_dest_options++] = *list;
+            dest[num_dest_options].name = NULL;
+        }
+        list++;
+    }
+
+    return dest;
+}
+
+/*
  * Parses a parameter string (param) into an option list (dest).
  *
  * list is the templace is. If dest is NULL, a new copy of list is created for
@@ -365,7 +410,6 @@ void free_option_parameters(QEMUOptionParameter *list)
 QEMUOptionParameter *parse_option_parameters(const char *param,
     QEMUOptionParameter *list, QEMUOptionParameter *dest)
 {
-    QEMUOptionParameter *cur;
     QEMUOptionParameter *allocated = NULL;
     char name[256];
     char value[256];
@@ -379,12 +423,7 @@ QEMUOptionParameter *parse_option_parameters(const char *param,
 
     if (dest == NULL) {
         // Count valid options
-        num_options = 0;
-        cur = list;
-        while (cur->name) {
-            num_options++;
-            cur++;
-        }
+        num_options = count_option_parameters(list);
 
         // Create a copy of the option list to fill in values
         dest = qemu_mallocz((num_options + 1) * sizeof(QEMUOptionParameter));
diff --git a/qemu-option.h b/qemu-option.h
index 58136f3032..4823219a18 100644
--- a/qemu-option.h
+++ b/qemu-option.h
@@ -70,6 +70,8 @@ int set_option_parameter(QEMUOptionParameter *list, const char *name,
     const char *value);
 int set_option_parameter_int(QEMUOptionParameter *list, const char *name,
     uint64_t value);
+QEMUOptionParameter *append_option_parameters(QEMUOptionParameter *dest,
+    QEMUOptionParameter *list);
 QEMUOptionParameter *parse_option_parameters(const char *param,
     QEMUOptionParameter *list, QEMUOptionParameter *dest);
 void free_option_parameters(QEMUOptionParameter *list);
diff --git a/vl.c b/vl.c
index 417554fc64..7121cd0264 100644
--- a/vl.c
+++ b/vl.c
@@ -953,7 +953,7 @@ DriveInfo *drive_init(QemuOpts *opts, void *opaque,
 
     on_write_error = BLOCK_ERR_STOP_ENOSPC;
     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
-        if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO) {
+        if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type != IF_NONE) {
             fprintf(stderr, "werror is no supported by this format\n");
             return NULL;
         }
@@ -966,7 +966,7 @@ DriveInfo *drive_init(QemuOpts *opts, void *opaque,
 
     on_read_error = BLOCK_ERR_REPORT;
     if ((buf = qemu_opt_get(opts, "rerror")) != NULL) {
-        if (type != IF_IDE && type != IF_VIRTIO) {
+        if (type != IF_IDE && type != IF_VIRTIO && type != IF_NONE) {
             fprintf(stderr, "rerror is no supported by this format\n");
             return NULL;
         }
@@ -1114,7 +1114,7 @@ DriveInfo *drive_init(QemuOpts *opts, void *opaque,
         /* CDROM is fine for any interface, don't check.  */
         ro = 1;
     } else if (ro == 1) {
-        if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY) {
+        if (type != IF_SCSI && type != IF_VIRTIO && type != IF_FLOPPY && type != IF_NONE) {
             fprintf(stderr, "qemu: readonly flag not supported for drive with this interface\n");
             return NULL;
         }