Re: [Qemu-devel] [PATCH 2/2] vl: Print CPU help after we've registered the CPU accelerators

[Thomas Huth <thuth@redhat.com>]

On 08.03.2017 15:50, Eduardo Habkost wrote:
> On Wed, Mar 08, 2017 at 03:31:01PM +0100, Peter Maydell wrote:
>> On 3 March 2017 at 15:58, Eduardo Habkost <ehabkost@redhat.com> wrote:
>>> On Tue, Jan 31, 2017 at 02:11:59PM +0100, Thomas Huth wrote:
>>>> When running with KVM on POWER, we register some CPU types during
>>>> the initialization function of the ppc64 KVM code (which unfortunately
>>>> also can not be done via a type_init() like it is done on x86).
>>>
>>> Can you elaborate why it can't be done via type_init()? If the
>>> QOM type hierarchy depends on any runtime data unavailable at
>>> type_init(), we should fix that.
>>
>> On ARM we (currently) have the KVM-only 'host' CPU type be
>> added to the type hierarchy only at runtime in kvm_init(),
>> but we deal with the '-help' problem by having arm_cpu_list() do
>>
>> #ifdef CONFIG_KVM
>>     /* The 'host' CPU type is dynamically registered only if KVM is
>>      * enabled, so we have to special-case it here:
>>      */
>>     (*cpu_fprintf)(f, "  host (only available in KVM mode)\n");
>> #endif
>>
> 
> We already have similar code at ppc_cpu_list():
> 
> #ifdef CONFIG_KVM
>     cpu_fprintf(f, "\n");
>     cpu_fprintf(f, "PowerPC %-16s\n", "host");
> #endif
> 
> If I understood it correctly, the current problem is just
> inaccurate alias information being printed because the alias
> table is modified by the accelerator.

Yes.

> My current suggestion is to avoid printing anything that depends
> on the current machine/accelerator at the help output.

I'll have a look at that...

 Thomas