Re: [Qemu-trivial] [Qemu-devel] [RFC PATCH 4/4] qemu-options: Do not show -enable-kvm and -enable-hax in the docs anymore

[Markus Armbruster <armbru@redhat.com>]

Eduardo Habkost <ehabkost@redhat.com> writes:

> On Tue, Jun 26, 2018 at 09:50:04AM +0200, Cornelia Huck wrote:
>> On Tue, 26 Jun 2018 06:40:56 +0200
>> Thomas Huth <thuth@redhat.com> wrote:
>> 
>> > On 25.06.2018 20:26, Paolo Bonzini wrote:
>> > > On 25/06/2018 19:30, Eduardo Habkost wrote:  
>> > >>>> Attentive distros could even replace the wrapper script by a link.  
>> > >>> If they are okay with replacing the "KVM only" semantics with "KVM or
>> > >>> TCG", which I think is generally worse.  
>> > >>
>> > >> If we can't get agreement on what's the right default for each
>> > >> QEMU binary, I think that's yet another reason to document that
>> > >> upstream QEMU won't guarantee ABI compatibility if -accel is
>> > >> omitted.  
>> > > 
>> > > Before that we should ask what the benefit is in changing the default
>> > > for qemu-system-*.  Nobody is using it in practice to start QEMU with
>> > > KVM enabled...  
>> > 
>> > That's certainly not true. I've seen a couple of times already that
>> > people ask on IRC why their guests are running so slow, and if you ask
>> > them about their command line, it's obvious that they simply were not
>> > aware of "-accel" / "-enable-kvm" yet.
>> > 
>> > <semi-sarcastic>
>> > Maybe we simply should add a "--verbose" command line option that people
>> > can use to diagnose their problems:
>> > 
>> > $ qemu-system-x86_64 --verbose
>> > QEMU emulator version 2.12.50
>> > Using 'tcg' accelerator. Use '-accel kvm' to speed things up.
>> > Machine type is 'pc-i440fx-3.0'. Use 'q35' for a more modern machine.
>> > ....
>> > </semi-sarcastic>
>> 
>> Not sure how serious you meant that, but I actually quite like the
>> idea :)
>
> Also, this mode could be enabled by default if stderr is a tty.

It could be enabled by default, period.

Our inability to change defaults that have become sub-optimal for most
users is depressing.