diff options
| -rw-r--r-- | blockdev.c | 11 | ||||
| -rw-r--r-- | qemu-options.hx | 2 |
2 files changed, 13 insertions, 0 deletions
diff --git a/blockdev.c b/blockdev.c index b307ed9ba9..0e67d06330 100644 --- a/blockdev.c +++ b/blockdev.c @@ -391,6 +391,13 @@ DriveInfo *drive_init(QemuOpts *opts, BlockInterfaceType block_default_type) } } + if ((buf = qemu_opt_get(opts, "discard")) != NULL) { + if (bdrv_parse_discard_flags(buf, &bdrv_flags) != 0) { + error_report("invalid discard option"); + return NULL; + } + } + bdrv_flags |= BDRV_O_CACHE_WB; if ((buf = qemu_opt_get(opts, "cache")) != NULL) { if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) { @@ -1501,6 +1508,10 @@ QemuOptsList qemu_drive_opts = { .type = QEMU_OPT_STRING, .help = "disk image", },{ + .name = "discard", + .type = QEMU_OPT_STRING, + .help = "discard operation (ignore/off, unmap/on)", + },{ .name = "cache", .type = QEMU_OPT_STRING, .help = "host cache usage (none, writeback, writethrough, " diff --git a/qemu-options.hx b/qemu-options.hx index 2832d82148..51ff726490 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -440,6 +440,8 @@ These options have the same definition as they have in @option{-hdachs}. @var{cache} is "none", "writeback", "unsafe", "directsync" or "writethrough" and controls how the host cache is used to access block data. @item aio=@var{aio} @var{aio} is "threads", or "native" and selects between pthread based disk I/O and native Linux AIO. +@item discard=@var{discard} +@var{discard} is one of "ignore" (or "off") or "unmap" (or "on") and controls whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap}) requests are ignored or passed to the filesystem. Some machine types may not support discard requests. @item format=@var{format} Specify which disk @var{format} will be used rather than detecting the format. Can be used to specifiy format=raw to avoid interpreting |