Re: [PATCH] LoongArch: KVM: Move some variable declaration to file paravirt.h

[Bibo Mao <maobibo@loongson.cn>]

On 2026/5/8 下午9:04, Huacai Chen wrote:
> On Fri, May 8, 2026 at 11:19 AM Bibo Mao <maobibo@loongson.cn> wrote:
>>
>>
>>
>> On 2026/5/8 上午11:11, Huacai Chen wrote:
>>> On Fri, May 8, 2026 at 11:08 AM Bibo Mao <maobibo@loongson.cn> wrote:
>>>>
>>>>
>>>>
>>>> On 2026/5/8 上午10:56, Huacai Chen wrote:
>>>>> Hi, Bibo,
>>>>>
>>>>> On Fri, May 8, 2026 at 9:30 AM Bibo Mao <maobibo@loongson.cn> wrote:
>>>>>>
>>>>>> Some variables relative with paravirt feature are declared in header file
>>>>>> asm/qspinlock.h, however this file can be included only when option
>>>>>> CONFIG_SMP is on. There is compiling warning if CONFIG_SMP is off since
>>>>>> it is not declared.
>>>>>>
>>>>>> Move these variable declaration to header file asm/paravirt.h to avoid
>>>>>> compiling warning.
>>>>> Have you reproduced the warning? I cannot reproduce it in my
>>>>> environment with the config file from lkp report, so I also cannot
>>>>> confirm whether it is fixed.
>>>> yes, I can reproduce this and it is fixed. The warning is reported from
>>>> sparse tool, rather than LLVM.
>>>>>
>>>>> Another question:
>>>>> Is paravirt.h a better place than kvm_para.h?
>>>> en, here kvm_para.h seems better, will send V2 version in next time.
>>> Frankly, I don't know the difference between the two files. kvm_para.h
>>> is kvm specific and paravirt.h is generic? Or kvm_para.h is the
>>> hypervisor side and paravirt.h is the guest side?
>> kvm_para.h is shared by hypervisor and guest kernel, paravirt.h is only
>> used by guest kernel. And option CONFIG_PARAVIRT is useful with guest
>> kernel, CONFIG_PARAVIRT has no much meaning with hypervisor.
> If so, paravirt.h seems better to declare these variables.
yes, paravirt.h seems better than kvm_para.h :)

Regards
Bibo Mao
> 
> Huacai
> 
>>
>> Regards
>> Bibo Mao
>>>
>>> Huacai
>>>
>>>>
>>>> Regards
>>>> Bibo Mao
>>>>
>>>>>
>>>>> Huacai
>>>>>
>>>>>>
>>>>>> Fixes: c43dce6f13fb ("LoongArch: KVM: Make vcpu_is_preempted() as a macro rather than function")
>>>>>> Reported-by: kernel test robot <lkp@intel.com>
>>>>>> Closes: https://lore.kernel.org/oe-kbuild-all/202605061313.O8Hswm2b-lkp@intel.com/
>>>>>> Signed-off-by: Bibo Mao <maobibo@loongson.cn>
>>>>>> ---
>>>>>>     arch/loongarch/include/asm/paravirt.h  | 4 ++++
>>>>>>     arch/loongarch/include/asm/qspinlock.h | 5 +----
>>>>>>     2 files changed, 5 insertions(+), 4 deletions(-)
>>>>>>
>>>>>> diff --git a/arch/loongarch/include/asm/paravirt.h b/arch/loongarch/include/asm/paravirt.h
>>>>>> index 0111f0ad5f73..dbc64908017f 100644
>>>>>> --- a/arch/loongarch/include/asm/paravirt.h
>>>>>> +++ b/arch/loongarch/include/asm/paravirt.h
>>>>>> @@ -3,6 +3,10 @@
>>>>>>     #define _ASM_LOONGARCH_PARAVIRT_H
>>>>>>
>>>>>>     #ifdef CONFIG_PARAVIRT
>>>>>> +#include <linux/jump_label.h>
>>>>>> +DECLARE_STATIC_KEY_FALSE(virt_preempt_key);
>>>>>> +DECLARE_STATIC_KEY_FALSE(virt_spin_lock_key);
>>>>>> +DECLARE_PER_CPU(struct kvm_steal_time, steal_time);
>>>>>>
>>>>>>     int __init pv_ipi_init(void);
>>>>>>     int __init pv_time_init(void);
>>>>>> diff --git a/arch/loongarch/include/asm/qspinlock.h b/arch/loongarch/include/asm/qspinlock.h
>>>>>> index 0ee15b3b3937..fbfc6be82f26 100644
>>>>>> --- a/arch/loongarch/include/asm/qspinlock.h
>>>>>> +++ b/arch/loongarch/include/asm/qspinlock.h
>>>>>> @@ -3,12 +3,9 @@
>>>>>>     #define _ASM_LOONGARCH_QSPINLOCK_H
>>>>>>
>>>>>>     #include <asm/kvm_para.h>
>>>>>> -#include <linux/jump_label.h>
>>>>>> +#include <asm/paravirt.h>
>>>>>>
>>>>>>     #ifdef CONFIG_PARAVIRT
>>>>>> -DECLARE_STATIC_KEY_FALSE(virt_preempt_key);
>>>>>> -DECLARE_STATIC_KEY_FALSE(virt_spin_lock_key);
>>>>>> -DECLARE_PER_CPU(struct kvm_steal_time, steal_time);
>>>>>>
>>>>>>     #define virt_spin_lock virt_spin_lock
>>>>>>
>>>>>>
>>>>>> base-commit: 74fe02ce122a6103f207d29fafc8b3a53de6abaf
>>>>>> --
>>>>>> 2.39.3
>>>>>>
>>>>
>>