Re: [PATCH 2/6] LoongArch: KVM: Add separate vCPU and VM id update function

On 2026/8/2 下午10:12, Huacai Chen wrote:
> Hi, Bibo,
> 
> On Mon, Jul 27, 2026 at 3:29 PM Bibo Mao <[email protected]> wrote:
>>
>> There are two-level MMU on LoongArch KVM system, the first level (stage1)
>> MMU is mapping for GVA --> GPA, the second level (stage2) is mapping
>> for GPA --> HPA. Similar with ASID, there is different ID management
>> to support multiple VMs and vCPUs. The stage1 MMU is called vCPUID, and
>> the second MMU is called VMID, the corresponding ID management function
>> is kvm_check_vcpuid() and kvm_check_vmid().
>>
>> Signed-off-by: Bibo Mao <[email protected]>
>> ---
>>   arch/loongarch/kvm/main.c | 21 ++++++++++++++++++---
>>   1 file changed, 18 insertions(+), 3 deletions(-)
>>
>> diff --git a/arch/loongarch/kvm/main.c b/arch/loongarch/kvm/main.c
>> index 6e3e8efa1dc2..c1e1d8424fa7 100644
>> --- a/arch/loongarch/kvm/main.c
>> +++ b/arch/loongarch/kvm/main.c
>> @@ -223,10 +223,9 @@ static void kvm_update_vpid(struct kvm_vcpu *vcpu, int cpu)
>>
>>          context->vpid_cache = vpid;
>>          vcpu->arch.vpid = vpid;
>> -       vcpu->arch.vmid = vcpu->arch.vpid & vpid_mask;
>>   }
>>
>> -void kvm_check_vpid(struct kvm_vcpu *vcpu)
>> +static void kvm_check_vcpuid(struct kvm_vcpu *vcpu)
>>   {
>>          int cpu;
>>          bool migrated;
>> @@ -254,7 +253,6 @@ void kvm_check_vpid(struct kvm_vcpu *vcpu)
>>                  kvm_update_vpid(vcpu, cpu);
>>                  trace_kvm_vpid_change(vcpu, vcpu->arch.vpid);
>>                  vcpu->cpu = cpu;
>> -               kvm_clear_request(KVM_REQ_TLB_FLUSH_GPA, vcpu);
>>
>>                  /*
>>                   * LLBCTL is a separated guest CSR register from host, a general
>> @@ -280,6 +278,23 @@ void kvm_check_vpid(struct kvm_vcpu *vcpu)
>>          }
>>   }
>>
>> +static void kvm_check_vmid(struct kvm_vcpu *vcpu)
>> +{
>> +       unsigned long vmid;
>> +
>> +       vmid = vcpu->arch.vpid & vpid_mask;
>> +       if (vcpu->arch.vmid != vmid) {
>> +               vcpu->arch.vmid = vmid;
>> +               kvm_clear_request(KVM_REQ_TLB_FLUSH_GPA, vcpu);
>> +       }
>> +}
>> +
>> +void kvm_check_vpid(struct kvm_vcpu *vcpu)
>> +{
>> +       kvm_check_vcpuid(vcpu);
>> +       kvm_check_vmid(vcpu);
>> +}
> I think the previous naming is a little better:
> 
> +void kvm_check_vpid(struct kvm_vcpu *vcpu)
> +{
> + __kvm_check_vpid(vcpu);
> + __kvm_check_vmid(vcpu);
> +}
function name kvm_check_vcpuid() is actually strange, will do in this way.

Regards
Bibo Mao
> 
> 
> Huacai
> 
> 
>> +
>>   void kvm_init_vmcs(struct kvm *kvm)
>>   {
>>          kvm->arch.vmcs = vmcs;
>> --
>> 2.39.3
>>