diff options
author | 2016-06-03 03:33:22 +0000 | |
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committer | 2016-06-03 03:33:23 +0000 | |
commit | da27230f80795d0028333713f036d44c53cb0e68 (patch) | |
tree | b3d379eaf000adf72b36cb01cdf4d79c3e3f064c /qemu/block/null.c | |
parent | 0e68cb048bb8aadb14675f5d4286d8ab2fc35449 (diff) | |
parent | 437fd90c0250dee670290f9b714253671a990160 (diff) |
Merge "These changes are the raw update to qemu-2.6."
Diffstat (limited to 'qemu/block/null.c')
-rw-r--r-- | qemu/block/null.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/qemu/block/null.c b/qemu/block/null.c index 7d083233f..396500bab 100644 --- a/qemu/block/null.c +++ b/qemu/block/null.c @@ -10,13 +10,17 @@ * See the COPYING file in the top-level directory. */ +#include "qemu/osdep.h" +#include "qapi/error.h" #include "block/block_int.h" #define NULL_OPT_LATENCY "latency-ns" +#define NULL_OPT_ZEROES "read-zeroes" typedef struct { int64_t length; int64_t latency_ns; + bool read_zeroes; } BDRVNullState; static QemuOptsList runtime_opts = { @@ -39,6 +43,11 @@ static QemuOptsList runtime_opts = { .help = "nanoseconds (approximated) to wait " "before completing request", }, + { + .name = NULL_OPT_ZEROES, + .type = QEMU_OPT_BOOL, + .help = "return zeroes when read", + }, { /* end of list */ } }, }; @@ -60,6 +69,7 @@ static int null_file_open(BlockDriverState *bs, QDict *options, int flags, error_setg(errp, "latency-ns is invalid"); ret = -EINVAL; } + s->read_zeroes = qemu_opt_get_bool(opts, NULL_OPT_ZEROES, false); qemu_opts_del(opts); return ret; } @@ -89,6 +99,12 @@ static coroutine_fn int null_co_readv(BlockDriverState *bs, int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) { + BDRVNullState *s = bs->opaque; + + if (s->read_zeroes) { + qemu_iovec_memset(qiov, 0, 0, nb_sectors * BDRV_SECTOR_SIZE); + } + return null_co_common(bs); } @@ -158,6 +174,12 @@ static BlockAIOCB *null_aio_readv(BlockDriverState *bs, BlockCompletionFunc *cb, void *opaque) { + BDRVNullState *s = bs->opaque; + + if (s->read_zeroes) { + qemu_iovec_memset(qiov, 0, 0, nb_sectors * BDRV_SECTOR_SIZE); + } + return null_aio_common(bs, cb, opaque); } @@ -183,6 +205,24 @@ static int null_reopen_prepare(BDRVReopenState *reopen_state, return 0; } +static int64_t coroutine_fn null_co_get_block_status(BlockDriverState *bs, + int64_t sector_num, + int nb_sectors, int *pnum, + BlockDriverState **file) +{ + BDRVNullState *s = bs->opaque; + off_t start = sector_num * BDRV_SECTOR_SIZE; + + *pnum = nb_sectors; + *file = bs; + + if (s->read_zeroes) { + return BDRV_BLOCK_OFFSET_VALID | start | BDRV_BLOCK_ZERO; + } else { + return BDRV_BLOCK_OFFSET_VALID | start; + } +} + static BlockDriver bdrv_null_co = { .format_name = "null-co", .protocol_name = "null-co", @@ -196,6 +236,8 @@ static BlockDriver bdrv_null_co = { .bdrv_co_writev = null_co_writev, .bdrv_co_flush_to_disk = null_co_flush, .bdrv_reopen_prepare = null_reopen_prepare, + + .bdrv_co_get_block_status = null_co_get_block_status, }; static BlockDriver bdrv_null_aio = { @@ -211,6 +253,8 @@ static BlockDriver bdrv_null_aio = { .bdrv_aio_writev = null_aio_writev, .bdrv_aio_flush = null_aio_flush, .bdrv_reopen_prepare = null_reopen_prepare, + + .bdrv_co_get_block_status = null_co_get_block_status, }; static void bdrv_null_init(void) |