[PATCH 13/16] qemu-nbd: adds option for aio engines

[Stefan Hajnoczi <stefanha@redhat.com>]

From: Aarushi Mehta <mehta.aaru20@gmail.com>

Signed-off-by: Aarushi Mehta <mehta.aaru20@gmail.com>
Acked-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 qemu-nbd.c    | 12 ++++--------
 qemu-nbd.texi |  4 ++--
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/qemu-nbd.c b/qemu-nbd.c
index 9032b6de2a..afa969c785 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -135,7 +135,7 @@ static void usage(const char *name)
 "                            '[ID_OR_NAME]'\n"
 "  -n, --nocache             disable host cache\n"
 "      --cache=MODE          set cache mode (none, writeback, ...)\n"
-"      --aio=MODE            set AIO mode (native or threads)\n"
+"      --aio=MODE            set AIO mode (native, io_uring or threads)\n"
 "      --discard=MODE        set discard mode (ignore, unmap)\n"
 "      --detect-zeroes=MODE  set detect-zeroes mode (off, on, unmap)\n"
 "      --image-opts          treat FILE as a full set of image options\n"
@@ -719,13 +719,9 @@ int main(int argc, char **argv)
                 exit(EXIT_FAILURE);
             }
             seen_aio = true;
-            if (!strcmp(optarg, "native")) {
-                flags |= BDRV_O_NATIVE_AIO;
-            } else if (!strcmp(optarg, "threads")) {
-                /* this is the default */
-            } else {
-               error_report("invalid aio mode `%s'", optarg);
-               exit(EXIT_FAILURE);
+            if (bdrv_parse_aio(optarg, &flags) < 0) {
+                error_report("Invalid aio mode '%s'", optarg);
+                exit(EXIT_FAILURE);
             }
             break;
         case QEMU_NBD_OPT_DISCARD:
diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 7f55657722..3ee3e4bdee 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -77,8 +77,8 @@ as an read-only device, @var{snapshot_param} format is
 The cache mode to be used with the file.  See the documentation of
 the emulator's @code{-drive cache=...} option for allowed values.
 @item --aio=@var{aio}
-Set the asynchronous I/O mode between @samp{threads} (the default)
-and @samp{native} (Linux only).
+Set the asynchronous I/O mode between @samp{threads} (the default),
+@samp{native} (Linux only) and @samp{io_uring} (Linux 5.1+).
 @item --discard=@var{discard}
 Control whether @dfn{discard} (also known as @dfn{trim} or @dfn{unmap})
 requests are ignored or passed to the filesystem.  @var{discard} is one of
-- 
2.21.0