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>
}
}
+ 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) {
.name = "file",
.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,
@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