Add support for BDRV_O_UNMAP from the QEMU command-line.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
blockdev.c | 11 +++++++++++
qemu-options.hx | 2 ++
2 files changed, 13 insertions(+)
diff --git a/blockdev.c b/blockdev.c
index 63e6f1e..b4ae36a 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -378,6 +378,13 @@ 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) {
@@ -1489,6 +1496,10 @@ 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 046bdc0..d5a99c7 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -185,6 +185,8 @@ 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
--
1.8.1.2
