From patchwork Fri Feb 8 13:06:12 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [2/5] blockdev: add discard suboption to -drive From: Paolo Bonzini X-Patchwork-Id: 219146 Message-Id: <1360328775-13144-3-git-send-email-pbonzini@redhat.com> To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com Date: Fri, 8 Feb 2013 14:06:12 +0100 Add support for BDRV_O_UNMAP from the QEMU command-line. Signed-off-by: Paolo Bonzini --- 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