diff --git a/blockdev.c b/blockdev.c index d8e3e31975..b65891382b 100644 --- a/blockdev.c +++ b/blockdev.c @@ -469,6 +469,7 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts, int bdrv_flags = 0; int on_read_error, on_write_error; bool account_invalid, account_failed; + bool writethrough; BlockBackend *blk; BlockDriverState *bs; ThrottleConfig cfg; @@ -507,6 +508,8 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts, account_invalid = qemu_opt_get_bool(opts, "stats-account-invalid", true); account_failed = qemu_opt_get_bool(opts, "stats-account-failed", true); + writethrough = !qemu_opt_get_bool(opts, BDRV_OPT_CACHE_WB, true); + qdict_extract_subqdict(bs_opts, &interval_dict, "stats-intervals."); qdict_array_split(interval_dict, &interval_list); @@ -592,7 +595,7 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts, /* bdrv_open() defaults to the values in bdrv_flags (for compatibility * with other callers) rather than what we want as the real defaults. * Apply the defaults here instead. */ - qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_WB, "on"); + qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_WB, writethrough ? "off" : "on"); qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_DIRECT, "off"); qdict_set_default_str(bs_opts, BDRV_OPT_CACHE_NO_FLUSH, "off"); @@ -630,6 +633,7 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts, } } + blk_set_enable_write_cache(blk, !writethrough); blk_set_on_error(blk, on_read_error, on_write_error); if (!monitor_add_blk(blk, qemu_opts_id(opts), errp)) { @@ -4130,6 +4134,10 @@ QemuOptsList qemu_common_drive_opts = { .name = "aio", .type = QEMU_OPT_STRING, .help = "host AIO implementation (threads, native)", + },{ + .name = BDRV_OPT_CACHE_WB, + .type = QEMU_OPT_BOOL, + .help = "Enable writeback mode", },{ .name = "format", .type = QEMU_OPT_STRING,