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

Tianjia Zhang
2020-04-23T03:01:52Z

On 2020/4/23 0:04, Cornelia Huck wrote:
> On Wed, 22 Apr 2020 17:58:04 +0200
> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
>
>> On 22.04.20 15:45, Cornelia Huck wrote:
>>> On Wed, 22 Apr 2020 20:58:04 +0800
>>> Tianjia Zhang <tianjia.zhang@linux.alibaba.com> 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/ ?
>>>
>>>> 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@linux.alibaba.com>
>>>> ---
>>>> 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?
>>
>> Agreed. It feels kind of random. Maybe just do the first line (move kvm_run from the
>> function parameter list into the variable declaration)? Not sure if this is better.
>>
>
> There's more in this patch that I cut... but I think just moving
> kvm_run from the parameter list would be much less disruptive.
>

I think there are two kinds of code(`vcpu->run->` and `kvm_run->`), but
there will be more disruptive, not less.

Thanks,
Tianjia