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Diffstat (limited to 'block/vmdk.c')
-rw-r--r--block/vmdk.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/block/vmdk.c b/block/vmdk.c
index 7e07c0f6e6..cc19e207d1 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -48,6 +48,8 @@
#define VMDK_UNALLOC (-2)
#define VMDK_ZEROED (-3)
+#define BLOCK_OPT_ZEROED_GRAIN "zeroed_grain"
+
typedef struct {
uint32_t version;
uint32_t flags;
@@ -1262,7 +1264,7 @@ static coroutine_fn int vmdk_co_write(BlockDriverState *bs, int64_t sector_num,
static int vmdk_create_extent(const char *filename, int64_t filesize,
- bool flat, bool compress)
+ bool flat, bool compress, bool zeroed_grain)
{
int ret, i;
int fd = 0;
@@ -1284,9 +1286,10 @@ static int vmdk_create_extent(const char *filename, int64_t filesize,
}
magic = cpu_to_be32(VMDK4_MAGIC);
memset(&header, 0, sizeof(header));
- header.version = 1;
- header.flags =
- 3 | (compress ? VMDK4_FLAG_COMPRESS | VMDK4_FLAG_MARKER : 0);
+ header.version = zeroed_grain ? 2 : 1;
+ header.flags = 3
+ | (compress ? VMDK4_FLAG_COMPRESS | VMDK4_FLAG_MARKER : 0)
+ | (zeroed_grain ? VMDK4_FLAG_ZERO_GRAIN : 0);
header.compressAlgorithm = compress ? VMDK4_COMPRESSION_DEFLATE : 0;
header.capacity = filesize / 512;
header.granularity = 128;
@@ -1467,6 +1470,7 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options)
char parent_desc_line[BUF_SIZE] = "";
uint32_t parent_cid = 0xffffffff;
uint32_t number_heads = 16;
+ bool zeroed_grain = false;
const char desc_template[] =
"# Disk DescriptorFile\n"
"version=1\n"
@@ -1502,6 +1506,8 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options)
flags |= options->value.n ? BLOCK_FLAG_COMPAT6 : 0;
} else if (!strcmp(options->name, BLOCK_OPT_SUBFMT)) {
fmt = options->value.s;
+ } else if (!strcmp(options->name, BLOCK_OPT_ZEROED_GRAIN)) {
+ zeroed_grain |= options->value.n;
}
options++;
}
@@ -1588,7 +1594,8 @@ static int vmdk_create(const char *filename, QEMUOptionParameter *options)
snprintf(ext_filename, sizeof(ext_filename), "%s%s",
path, desc_filename);
- if (vmdk_create_extent(ext_filename, size, flat, compress)) {
+ if (vmdk_create_extent(ext_filename, size,
+ flat, compress, zeroed_grain)) {
return -EINVAL;
}
filesize -= size;
@@ -1714,6 +1721,11 @@ static QEMUOptionParameter vmdk_create_options[] = {
"VMDK flat extent format, can be one of "
"{monolithicSparse (default) | monolithicFlat | twoGbMaxExtentSparse | twoGbMaxExtentFlat | streamOptimized} "
},
+ {
+ .name = BLOCK_OPT_ZEROED_GRAIN,
+ .type = OPT_FLAG,
+ .help = "Enable efficient zero writes using the zeroed-grain GTE feature"
+ },
{ NULL }
};