On 13.06.2018 17:19, Daniel P. Berrangé wrote: > On Wed, Jun 13, 2018 at 05:11:51PM +0200, Thomas Huth wrote: >> On 13.06.2018 15:44, Daniel P. Berrangé wrote: >>> On Wed, Jun 13, 2018 at 02:38:40PM +0100, Stefan Hajnoczi wrote: >>>> On Wed, Jun 13, 2018 at 07:05:21AM +0200, Thomas Huth wrote: >>>>> We've got three ways of enabling an accelerator: -machine accel=xyz, >>>>> -accel xyz and -enable-xyz. For new QEMU users, this must be very >>>>> confusing ("Which one do I have to use? Is there a difference between >>>>> the options?"). While -enable-kvm was useful in the past, there is no >>>>> real good reason for using it anymore today ("-accel kvm" is even less >>>>> to type than "-enable-kvm"), so let's decrease the confusing amount of >>>>> options in our documenation a little bit by removing the -enable-xyz >>>>> here. Note that the option itself is neither removed nor marked as >>>>> deprecated - since -enable-kvm is likely used in a lot of scripts and >>>>> since its code is easy to maintain, we should keep it around to avoid >>>>> to break old setups. >>>>> >>>>> Signed-off-by: Thomas Huth <th...@redhat.com> >>>>> --- >>>>> PS: I guess Paolo won't like this patch ... let's try it anyway ;-) >>>> >>>> It's widely used and we're removing the documentation for it?! That is >>>> likely to cause issues for new users who refer to the man page to >>>> understand the QEMU command-lines they see online, in scripts, etc. >>> >>> Agreed, this is a very bad idea. Any option that is accepted by QEMU, >>> but not documented is a bug that must be fixed. IOW removing docs >>> is creating bugs. >> >> Not documenting unliked options that are still kept for compatibility >> was at least a common practice in the past (see -no-kvm for example, or >> many of those deprecated options like -net channel that have been >> removed in the past year). > > If we're planning to deprecate & then delete an option, then I > don't mind if docs are dropped, but IIUC, in this case we're > not doing that - the option will essentially exist forever. > >>> If we want to help users understand why we have -enable-kvm, just >>> make the docs say that it is syntactic for '-machine accel=kvm'. >>> Users can decide for themselves whether they want to switch to >>> the more verbose way or not >> >> Uh, well, in this case "-enable-kvm" is already the more verbose way: >> "-accel kvm" is shorter :-) > > If I'm a user looking for how to enable KVM, then -enable-kvm is the > one I'll pick because of the obvious name.
Hmm, maybe we should also add -configure-network-backend, --configure-character-device-backend and -setup-block-backend as synonyms for -netdev, -chardev and -blockdev, just because they have a more obvious name? ;-) Thomas