[Qemu-devel] [PATCH COLO-Block v5 09/15] Introduce a new -drive option to control whether to connect to remote target

[Wen Congyang <wency@cn.fujitsu.com>]

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
---
 blockdev.c            | 8 ++++++++
 include/block/block.h | 1 +
 qemu-options.hx       | 4 ++++
 3 files changed, 13 insertions(+)

diff --git a/blockdev.c b/blockdev.c
index 95a0c6a..0c457ee 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -429,6 +429,10 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
         qdict_put(bs_opts, "driver", qstring_from_str(buf));
     }
 
+    if (qemu_opt_get_bool(opts, "no-connect", false)) {
+        bdrv_flags |= BDRV_O_NO_CONNECT;
+    }
+
     /* disk I/O throttling */
     memset(&cfg, 0, sizeof(cfg));
     cfg.buckets[THROTTLE_BPS_TOTAL].avg =
@@ -3195,6 +3199,10 @@ QemuOptsList qemu_common_drive_opts = {
             .name = "detect-zeroes",
             .type = QEMU_OPT_STRING,
             .help = "try to optimize zero writes (off, on, unmap)",
+        },{
+            .name = "no-connect",
+            .type = QEMU_OPT_BOOL,
+            .help = "enable whether to connect remote target"
         },
         { /* end of list */ }
     },
diff --git a/include/block/block.h b/include/block/block.h
index e479a34..ed5b8e5 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -87,6 +87,7 @@ typedef struct HDGeometry {
 #define BDRV_O_PROTOCOL    0x8000  /* if no block driver is explicitly given:
                                       select an appropriate protocol driver,
                                       ignoring the format layer */
+#define BDRV_O_NO_CONNECT  0x10000 /* do not connect to remote target */
 
 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB | BDRV_O_NO_FLUSH)
 
diff --git a/qemu-options.hx b/qemu-options.hx
index ec356f6..c41e3e3 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -464,6 +464,7 @@ DEF("drive", HAS_ARG, QEMU_OPTION_drive,
     "       [[,bps_max=bm]|[[,bps_rd_max=rm][,bps_wr_max=wm]]]\n"
     "       [[,iops_max=im]|[[,iops_rd_max=irm][,iops_wr_max=iwm]]]\n"
     "       [[,iops_size=is]]\n"
+    "       [,no-connect=on|off]\n"
     "                use 'file' as a drive image\n", QEMU_ARCH_ALL)
 STEXI
 @item -drive @var{option}[,@var{option}[,@var{option}[,...]]]
@@ -525,6 +526,9 @@ file sectors into the image file.
 conversion of plain zero writes by the OS to driver specific optimized
 zero write commands. You may even choose "unmap" if @var{discard} is set
 to "unmap" to allow a zero write to be converted to an UNMAP operation.
+@item no-connect=@var{no-connect}
+@var{no-connect} is "on" or "off", and enables whether to connect to remote
+target when open the drive. The default value is "off".
 @end table
 
 By default, the @option{cache=writeback} mode is used. It will report data
-- 
2.1.0