Commit 69e0b6df authored by Fam Zheng's avatar Fam Zheng Committed by Stefan Hajnoczi
Browse files

vmdk: Add option to create zeroed-grain image 



Add image create option "zeroed-grain" to enable zeroed-grain GTE
feature of vmdk sparse extents. When this option is on, header version
of newly created extent will be 2 and VMDK4_FLAG_ZERO_GRAIN flag bit
will be set.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 14ead646

block/vmdk.c

+17 −5
Original line number Diff line number Diff line
@@ -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 }

};