Re: [PATCH v2 1/5] KVM: LAPIC: Introduce interrupt delivery fastpath

[Paolo Bonzini]

On 23/04/20 11:35, Wanpeng Li wrote:
>> Ok, got it now.  The problem is that deliver_posted_interrupt goes through
>>
>>         if (!kvm_vcpu_trigger_posted_interrupt(vcpu, false))
>>                 kvm_vcpu_kick(vcpu);
>>
>> Would it help to make the above
>>
>>         if (vcpu != kvm_get_running_vcpu() &&
>>             !kvm_vcpu_trigger_posted_interrupt(vcpu, false))
>>                 kvm_vcpu_kick(vcpu);
>>
>> ?  If that is enough for the APICv case, it's good enough.
> We will not exit from vmx_vcpu_run to vcpu_enter_guest, so it will not
> help, right?

Oh indeed---the call to sync_pir_to_irr is in vcpu_enter_guest.  You can
add it to patch 3 right before "goto cont_run", since AMD does not need it.

Paolo