openkylin
/
qemu
mirror of https://gitee.com/openkylin/qemu.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Paolo Bonzini 2013-02-08 14:06:12 +01:00 committed by Kevin Wolf
parent 9e8f1835ea
commit a9384aff53
2 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
blockdev.c
View File

@ -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) {
@ -1500,6 +1507,10 @@ QemuOptsList qemu_drive_opts = {
.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,

2
qemu-options.hx
View File

@ -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