Re: [Qemu-devel] [PATCH] target-i386: Improve x86_cpu_list output

[Igor Mammedov]

On Wed, 27 Feb 2013 08:52:50 +0100
Jan Kiszka <address@hidden> wrote:

> On 2013-02-27 08:37, Igor Mammedov wrote:
> > On Wed, 27 Feb 2013 00:26:38 -0300
> > Eduardo Habkost <address@hidden> wrote:
> > 
> >> On Tue, Feb 26, 2013 at 10:57:56PM +0100, Igor Mammedov wrote:
> >>> On Sat, 23 Feb 2013 16:45:00 +0100
> >>> Jan Kiszka <address@hidden> wrote:
> >>>
> >>>> From: Jan Kiszka <address@hidden>
> >>>>
> >>>> Several issues fixed:
> >>>>  - We were missing a bunch of feature lists. Fix this by simply dumping
> >>>>    the meta list feature_word_info.
> >>>>  - kvm_enabled() cannot be true at this point because accelerators are
> >>>>    initialized much later during init. Simply dump unconditionally.
> >>> Why not to move list_cpu after accelerators are initialized?
> >>
> >> Because help output is simply documentation and shouldn't depend on any
> >> other config option parsing or accelerator initialization at all?
> > Don't see reason why it shouldn't.
> > It's not a man page but a program and can do pretty much everything.
> 
> Actually, requiring "-enable-kvm -cpu ?" to list the host type would be
> counterproductive - hardly any user will find this out, at best by
> chance. However ...
> 
> > 
> >>
> >>>
> >>>>  - Add explanation for "host" CPU type.
> >>>>
> >>>> Signed-off-by: Jan Kiszka <address@hidden>
> >>>> ---
> >>>>  target-i386/cpu.c |   20 +++++++++-----------
> >>>>  1 files changed, 9 insertions(+), 11 deletions(-)
> >>>>
> >>>> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> >>>> index dfcf86e..6e742f0 100644
> >>>> --- a/target-i386/cpu.c
> >>>> +++ b/target-i386/cpu.c
> >>>> @@ -1453,18 +1453,16 @@ void x86_cpu_list(FILE *f, fprintf_function
> >>>> cpu_fprintf) snprintf(buf, sizeof(buf), "%s", def->name);
> >>>>          (*cpu_fprintf)(f, "x86 %16s  %-48s\n", buf, def->model_id);
> >>>>      }
> >>>> -    if (kvm_enabled()) {
> >>>> -        (*cpu_fprintf)(f, "x86 %16s\n", "[host]");
> >>>> -    }
> >>>> +    (*cpu_fprintf)(f, "x86 %16s  %-48s\n", "host",
> >>>> +                   "KVM processor with all supported host features");
> >>>> +
> >>> that would make 'host' visible to users even if QEMU compiled without
> >>> KVM support. No big harm, but autotest could get confused when it gets
> >>> 'host' CPU but QEMU doesn't run because it's not really supported.
> >>
> >> Then we have to fix the autotest test code to not try it without KVM.
> >> :-)
> >>
> >> Help output is not a probing mechanism (although we often misuse it as
> >> if it were), and I expect help output to be static and not depend on any
> >> subsystem initialization.
> > Then fix help output and add to "host" line something like " is available
> > with -enable-kvm on command line and if your build was compiled
> > --enable-kvm configure option", otherwise 'host' is misleading.
> > Now even without 'host' in output of -cpu 'help', question why 'host' is
> > not found periodically pops up on IRC. This change will just increase
> > frequency of it.
> 
> ...I will add "(only available in KVM mode)" here and wrap these lines
> in #ifdef CONFIG_KVM. That should be more acceptable, no?
yes, it will be better.

> Jan
> 
>