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

Tianjia Zhang
2020-04-23T10:59:02Z

On 2020/4/23 18:39, Cornelia Huck wrote:
> On Thu, 23 Apr 2020 11:01:43 +0800
> Tianjia Zhang <tianjia.zhang@linux.alibaba.com> wrote:
>
>> 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.
>
> I just fail to see the benefit; sure, kvm_run-> is convenient, but the
> current code is just fine, and any rework should be balanced against
> the cost (e.g. cluttering git annotate).
>

cluttering git annotate ? Does it mean Fix xxxx ("comment"). Is it
possible to solve this problem by splitting this patch?