On Fri, Jan 19, 2018 at 11:14:39AM +0100, Igor Mammedov wrote: > On Thu, 18 Jan 2018 17:18:09 -0200 > Eduardo Habkost <ehabk...@redhat.com> wrote: > > > On Thu, Jan 18, 2018 at 11:10:35AM +0100, Igor Mammedov wrote: > > > On Wed, 17 Jan 2018 23:48:46 -0200 > > > Eduardo Habkost <ehabk...@redhat.com> wrote: > > > > > > > On Wed, Jan 17, 2018 at 04:43:32PM +0100, Igor Mammedov wrote: > > > > > The last user of it was machine type 'none', which used field > > > > > to create CPU id user requested it on CLI with -cpu option. > [...] > > > It looks like default_cpu_type is being overloaded for two > > different roles: 1) specifying the default CPU type; 2) finding > > the arch-specific class to be used to parse -cpu. > > > > In the case of null-machine, these two roles conflict with each > > other. I believe we can find other solutions instead of this > > hack that involves lying on MachineClass::default_cpu_type (and > > then having to work around the lie on machine_none_init()). > > > > I see multiple options: adding a new MachineClass field for that > > (e.g. resolving_cpu_type, which defaults to default_cpu_type if > > NULL); moving the CPU parsing code to arch_init.c (so it could > > use CPU_RESOLVING_TYPE or something similar); adding a optional > > MachineClass::parse_cpu_model hook. We could even try to get rid > > of CPUClass::parse_features completely > Adding hooks just for the sake on null-machine seems to be overkill, > I'd go for arch_init.c but it won't work for linux-user, how about > exec.c as following: > > diff --git a/include/qom/cpu.h b/include/qom/cpu.h > index 93bd546..0185589 100644 > --- a/include/qom/cpu.h > +++ b/include/qom/cpu.h > @@ -661,8 +661,7 @@ ObjectClass *cpu_class_by_name(const char *typename, > const char *cpu_model); > [...] > > diff --git a/exec.c b/exec.c > index d28fc0c..4543f06 100644 > --- a/exec.c > +++ b/exec.c > @@ -817,6 +817,29 @@ void cpu_exec_realizefn(CPUState *cpu, Error **errp) > #endif > } > > +const char *parse_cpu_model(const char *cpu_model) > +{ > + ObjectClass *oc; > + CPUClass *cc; > + gchar **model_pieces; > + const char *cpu_type; > + > + model_pieces = g_strsplit(cpu_model, ",", 2); > + > + oc = cpu_class_by_name(CPU_RESOLVING_TYPE, model_pieces[0]); > + if (oc == NULL) { > + error_report("unable to find CPU model '%s'", model_pieces[0]); > + g_strfreev(model_pieces); > + exit(EXIT_FAILURE); > + } > + > + cpu_type = object_class_get_name(oc); > + cc = CPU_CLASS(oc); > + cc->parse_features(cpu_type, model_pieces[1], &error_fatal); > + g_strfreev(model_pieces); > + return cpu_type; > +}
Sounds good to me. Only two comments: This looks like duplication of cpu_parse_cpu_model(). Should this function body be replaced with: cpu_parse_cpu_model(CPU_RESOLVING_TYPE, cpu_model) ? I would move this to arch_init.c, because that's where existing target-dependent initialization code lives. > [...] -- Eduardo