On Wed, Nov 21, 2012 at 7:17 PM, mdroth <mdr...@linux.vnet.ibm.com> wrote: > On Tue, Nov 20, 2012 at 01:31:46PM +0100, Stefan Hajnoczi wrote: >> @@ -2233,6 +2238,17 @@ EOF >> fi >> >> ########################################## >> +# adjust virtio-blk-data-plane based on linux-aio >> + >> +if test "$virtio_blk_data_plane" = "yes" -a \ >> + "$linux_aio" != "yes" ; then >> + echo "Error: virtio-blk-data-plane requires Linux AIO, please try >> --enable-linux-aio" >> + exit 1 >> +elif test -z "$virtio_blk_data_plane" ; then >> + virtio_blk_data_plane=$linux_aio >> +fi > > $linux_aio gets set automatically if the user has libaio installed and > doesn't specify --disable-linux-aio, so this ends up enabling dataplane by > default in a lot of situations. Since it's experimental I think it should only > be enabled if we pass --enable-virtio-blk-data-plane explicitly.
I expect downstreams to enable this feature. Requiring package maintainers to add --enable-virtio-blk-data-one explicitly is probably going to cause more work than any benefits of disabling it by default. The feature has no effect unless -device virtio-blk-pci,x-data-plane-on is used. Code size is <12 KB on x86_64 and contains nothing especially risky from a security perspective. That said, if there is a strong feeling this should be disabled by default, I can switch it to default off. Stefan