Re: [PATCH] KVM: Loongarch: Remove undefined a6 argument comment for kvm_hypercall

[maobibo]

On 2024/7/26 上午10:55, Huacai Chen wrote:
> On Fri, Jul 26, 2024 at 9:49 AM maobibo <maobibo@xxxxxxxxxxx> wrote:
> > On 2024/7/25 下午9:48, Dandan Zhang wrote:
> > > The kvm_hypercall set for LoongArch is limited to a1-a5.
> > > The mention of a6 in the comment is undefined that needs to be rectified.
> > >
> > > Signed-off-by: Wentao Guan <guanwentao@xxxxxxxxxxxxx>
> > > Signed-off-by: Dandan Zhang <zhangdandan@xxxxxxxxxxxxx>
> > > ---
> > >    arch/loongarch/include/asm/kvm_para.h | 4 ++--
> > >    1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/arch/loongarch/include/asm/kvm_para.h b/arch/loongarch/include/asm/kvm_para.h
> > > index 335fb86778e2..43ec61589e6c 100644
> > > --- a/arch/loongarch/include/asm/kvm_para.h
> > > +++ b/arch/loongarch/include/asm/kvm_para.h
> > > @@ -39,9 +39,9 @@ struct kvm_steal_time {
> > >     * Hypercall interface for KVM hypervisor
> > >     *
> > >     * a0: function identifier
> > > - * a1-a6: args
> > > + * a1-a5: args
> > >     * Return value will be placed in a0.
> > > - * Up to 6 arguments are passed in a1, a2, a3, a4, a5, a6.
> > > + * Up to 5 arguments are passed in a1, a2, a3, a4, a5.
> > >     */
> > >    static __always_inline long kvm_hypercall0(u64 fid)
> > >    {
> >
> > Dandan,
> >
> > Nice catch. In future hypercall abi may expand such as the number of
> > input register and output register, or async hypercall function if there
> > is really such requirement.
> >
> > Anyway the modification is deserved and it is enough to use now, thanks
> > for doing it.
> >
> > Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>
> Maybe it is better to implement kvm_hypercall6() than remove a6 now?
That is one option also. The main reason is that there is no such 
requirement in near future :(, I prefer to removing the annotation and 
keeping it clean.

Regards
Bibo Mao
> Huacai
> >