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authorPaolo Bonzini <pbonzini@redhat.com>2013-02-08 14:06:12 +0100
committerKevin Wolf <kwolf@redhat.com>2013-02-22 21:29:42 +0100
commita9384aff5315e7568b6ebc171f4a482e01f06526 (patch)
tree6482bec7ed74afb86b53be6e563fe450dd4c252b
parent9e8f1835ea3ab3be83634f34c1bb8b69cd871766 (diff)
downloadqemu-arm-a9384aff5315e7568b6ebc171f4a482e01f06526.tar.gz
blockdev: add discard suboption to -drive
Add support for BDRV_O_UNMAP from the QEMU command-line. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--blockdev.c11
-rw-r--r--qemu-options.hx2
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