Commit 1501ecc1 authored by Stefan Hajnoczi's avatar Stefan Hajnoczi Committed by Kevin Wolf
Browse files

raw-posix: warn about BDRV_O_NATIVE_AIO if libaio is unavailable 



raw-posix.c silently ignores BDRV_O_NATIVE_AIO if libaio is unavailable.
It is confusing when aio=native performance is identical to aio=threads
because the binary was accidentally built without libaio.

Print a deprecation warning if -drive aio=native is used with a binary
that does not support libaio.  There are probably users using aio=native
who would be inconvenienced if QEMU suddenly refused to start their
guests.  In the future this will become an error.

Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 15489c76

block/raw-posix.c

+10 −1
Original line number Diff line number Diff line
@@ -519,7 +519,16 @@ static int raw_open_common(BlockDriverState *bs, QDict *options, 
                     "future QEMU versions.\n",

                     bs->filename);

    }

#endif

#else

    if (bdrv_flags & BDRV_O_NATIVE_AIO) {

        error_printf("WARNING: aio=native was specified for '%s', but "

                     "is not supported in this build. Falling back to "

                     "aio=threads.\n"

                     "         This will become an error condition in "

                     "future QEMU versions.\n",

                     bs->filename);

    }

#endif /* !defined(CONFIG_LINUX_AIO) */



    s->has_discard = true;

    s->has_write_zeroes = true;