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

[Eduardo Habkost <ehabkost@redhat.com>]

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.

-- 
Eduardo