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

[Bibo Mao <maobibo@loongson.cn>]

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.

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
>>>>
>>