Re: [Qemu-devel] [PATCH qom-cpu 1/4] target-i386: Inline -cpu host check into cpu_x86_register()

[Eduardo Habkost]

On Tue, Dec 11, 2012 at 12:21:10AM +0100, Andreas Färber wrote:
> Am 10.12.2012 19:55, schrieb Igor Mammedov:
> > On Mon, 10 Dec 2012 10:46:13 -0200
> > Eduardo Habkost <address@hidden> wrote:
> > 
> >> On Sun, Dec 09, 2012 at 08:45:50PM +0100, Andreas Färber wrote:
> >>> Simplifies the upcoming cleanup of cpu_x86_find_by_name().
> >>
> >> ...by making cpu_x86_register() more complicated, and having CPU model
> >> name lookup spread into different parts of the code.
> >>
> >> The CPU model lookup is a bit complex because of the "host" exception,
> >> but at least the complexity was hidden inside cpu_x86_find_by_name()
> >> (making it very easy to replace that logic by a CPU subclass lookup,
> >> later).
> 
> (Somehow I didn't get this message ... yet)
> 
> > +1
> 
> Could you guys re-review this in light of the subclasses patch? The
> issue I was facing is that I did not see a reliable way to register the
> host class depending on kvm_enabled(). Therefore ..._find_by_name()
> becomes the class lookup whereas the host check remains a special check
> in cpu_x86_init() [a faulty one I now see, ignoring "host-x86_64-cpu"].
> cpu_x86_register() is problematic in that it gets the X86CPU served on a
> silver plate, so it's too late to choose subclasses in that function.

I have a patch[1] to change that in my APIC-ID-topology work in progress
branch[2]. I can submit this (and maybe a few other code movements) as
PATCH tomorrow.

I have a branch for CPU subclasses using an approach similar to the one
you used, but that includes "host" as well[3]. But I was waiting until
the properties series is resubmitted, so I could use it as base and make
the subclass code simpler. I will take a deeper look at your RFC
tomorrow, and probably send additional comments.


[1] 
https://github.com/ehabkost/qemu-hacks/commit/850c5531c84839919d650b2dac6e98fa4c2529c4
[2] https://github.com/ehabkost/qemu-hacks/commits/work/apicid
[3] https://github.com/ehabkost/qemu-hacks/commits/work/cpu-model-classes

-- 
Eduardo