Re: [PATCH v2 1/7] KVM: s390: clean up redundant 'kvm_run' parameters

[Tianjia Zhang]

On 2020/4/22 21:45, Cornelia Huck wrote:
> On Wed, 22 Apr 2020 20:58:04 +0800
> Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx> wrote:
>
> > In the current kvm version, 'kvm_run' has been included in the 'kvm_vcpu'
> > structure. Earlier than historical reasons, many kvm-related function
>
> s/Earlier than/For/ ?

Yes, it should be replaced like this.

> > parameters retain the 'kvm_run' and 'kvm_vcpu' parameters at the same time.
> > This patch does a unified cleanup of these remaining redundant parameters.
> >
> > Signed-off-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx>
> > ---
> >   arch/s390/kvm/kvm-s390.c | 37 ++++++++++++++++++++++---------------
> >   1 file changed, 22 insertions(+), 15 deletions(-)
> >
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index e335a7e5ead7..d7bb2e7a07ff 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -4176,8 +4176,9 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
> >   	return rc;
> >   }
> >   
> > -static void sync_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
> > +static void sync_regs_fmt2(struct kvm_vcpu *vcpu)
> >   {
> > +	struct kvm_run *kvm_run = vcpu->run;
> >   	struct runtime_instr_cb *riccb;
> >   	struct gs_cb *gscb;
> >   
> > @@ -4235,7 +4236,7 @@ static void sync_regs_fmt2(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
> >   		}
> >   		if (vcpu->arch.gs_enabled) {
> >   			current->thread.gs_cb = (struct gs_cb *)
> > -						&vcpu->run->s.regs.gscb;
> > +						&kvm_run->s.regs.gscb;
>
> Not sure if these changes (vcpu->run-> => kvm_run->) are really worth
> it. (It seems they amount to at least as much as the changes advertised
> in the patch description.)
>
> Other opinions?

Why not replace `vcpu->run->` to `kvm_run->` ? If not, there will be 
both styles of code, which is confusing. I will be confused and think 
that this is something different.

Thanks,
Tianjia

> >   			restore_gs_cb(current->thread.gs_cb);
> >   		}
> >   		preempt_enable();