Re: [PULL 48/65] target/riscv/cpu.c: split kvm prop handling to its own helper

[Daniel Henrique Barboza]

On 9/8/23 10:21, Philippe Mathieu-Daudé wrote:
> On 8/9/23 08:04, Alistair Francis wrote:
> > From: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> >
> > Future patches will split the existing Property arrays even further, and
> > the existing code in riscv_cpu_add_user_properties() will start to scale
> > bad with it because it's dealing with KVM constraints mixed in with TCG
> > constraints. We're going to pay a high price to share a couple of common
> > lines of code between the two.
> >
> > Create a new riscv_cpu_add_kvm_properties() that will be forked from
> > riscv_cpu_add_user_properties() if we're running KVM. The helper
> > includes all properties that a KVM CPU will add. The rest of
> > riscv_cpu_add_user_properties() body will then be relieved from having
> > to deal with KVM constraints.
> >
> > Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> > Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
> > Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
> > Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> > Message-ID: <20230901194627.1214811-4-dbarboza@ventanamicro.com>
> > Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> > ---
> >   target/riscv/cpu.c | 65 ++++++++++++++++++++++++++++++----------------
> >   1 file changed, 42 insertions(+), 23 deletions(-)
> >
> > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> > index db640e7460..8e6d316500 100644
> > --- a/target/riscv/cpu.c
> > +++ b/target/riscv/cpu.c
> > @@ -1943,6 +1943,46 @@ static void cpu_set_cfg_unavailable(Object *obj, Visitor 
> > *v,
> >   }
> >   #endif
> > +#ifndef CONFIG_USER_ONLY
>
> #ifdef CONFIG_KVM ?

Yeah, CONFIG_KVM would be more fitting here. We're moving all this code to kvm.c
in "[PATCH v2 00/19] riscv: split TCG/KVM accelerators from cpu.c", and we won't
need neither in the end, so for now it's simpler to temporarily leave it like
this.


Thanks,

Daniel

> > +static void riscv_cpu_add_kvm_unavail_prop(Object *obj, const char *prop_name)
> > +{
> > +    /* Check if KVM created the property already */
> > +    if (object_property_find(obj, prop_name)) {
> > +        return;
> > +    }
> > +
> > +    /*
> > +     * Set the default to disabled for every extension
> > +     * unknown to KVM and error out if the user attempts
> > +     * to enable any of them.
> > +     */
> > +    object_property_add(obj, prop_name, "bool",
> > +                        NULL, cpu_set_cfg_unavailable,
> > +                        NULL, (void *)prop_name);
> > +}
> > +
> > +static void riscv_cpu_add_kvm_properties(Object *obj)
> > +{
> > +    Property *prop;
> > +    DeviceState *dev = DEVICE(obj);
> > +
> > +    kvm_riscv_init_user_properties(obj);
> > +    riscv_cpu_add_misa_properties(obj);
> > +
> > +    for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
> > +        riscv_cpu_add_kvm_unavail_prop(obj, prop->name);
> > +    }
> > +
> > +    for (int i = 0; i < ARRAY_SIZE(riscv_cpu_options); i++) {
> > +        /* Check if KVM created the property already */
> > +        if (object_property_find(obj, riscv_cpu_options[i].name)) {
> > +            continue;
> > +        }
> > +        qdev_property_add_static(dev, &riscv_cpu_options[i]);
> > +    }
> > +}
> > +#endif
> > +
> >   /*
> >    * Add CPU properties with user-facing flags.
> >    *
> > @@ -1958,39 +1998,18 @@ static void riscv_cpu_add_user_properties(Object *obj)
> >       riscv_add_satp_mode_properties(obj);
> >       if (kvm_enabled()) {
> > -        kvm_riscv_init_user_properties(obj);
> > +        riscv_cpu_add_kvm_properties(obj);
> > +        return;
> >       }
> >   #endif
> >       riscv_cpu_add_misa_properties(obj);
> >       for (prop = riscv_cpu_extensions; prop && prop->name; prop++) {
> > -#ifndef CONFIG_USER_ONLY
> > -        if (kvm_enabled()) {
> > -            /* Check if KVM created the property already */
> > -            if (object_property_find(obj, prop->name)) {
> > -                continue;
> > -            }
> > -
> > -            /*
> > -             * Set the default to disabled for every extension
> > -             * unknown to KVM and error out if the user attempts
> > -             * to enable any of them.
> > -             */
> > -            object_property_add(obj, prop->name, "bool",
> > -                                NULL, cpu_set_cfg_unavailable,
> > -                                NULL, (void *)prop->name);
> > -            continue;
> > -        }
> > -#endif
> >           qdev_property_add_static(dev, prop);
> >       }
> >       for (int i = 0; i < ARRAY_SIZE(riscv_cpu_options); i++) {
> > -        /* Check if KVM created the property already */
> > -        if (object_property_find(obj, riscv_cpu_options[i].name)) {
> > -            continue;
> > -        }
> >           qdev_property_add_static(dev, &riscv_cpu_options[i]);
> >       }
> >   }