Re: [PATCH] x86/smp: Add irq_enter/exit() in smp_reschedule_interrupt()

From: Wanpeng Li
Date: Wed Oct 19 2016 - 10:15:11 EST


2016-10-18 8:01 GMT+08:00 Wanpeng Li <kernellwp@xxxxxxxxx>:
> 2016-10-17 18:08 GMT+08:00 Paolo Bonzini <pbonzini@xxxxxxxxxx>:
> [...]
>>> > Something like the below avoids all that. Paravirt will still need fixing.
>>>
>>> kvm_guest_apic_eoi_write
>>> -> native_apic_msr_write
>>
>> kvm_guest_apic_eoi_write can use native_apic_msr_eoi_write too:
>>
>> diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
>> index f5aaf6c83222..9769d76a62c4 100644
>> --- a/arch/x86/include/asm/apic.h
>> +++ b/arch/x86/include/asm/apic.h
>> @@ -174,7 +174,7 @@ static inline void disable_local_APIC(void) { }
>> static inline void lapic_update_tsc_freq(void) { }
>> #endif /* !CONFIG_X86_LOCAL_APIC */
>>
>> -#ifdef CONFIG_X86_X2APIC
>> +#if defined CONFIG_X86_X2APIC || defined CONFIG_KVM_GUEST
>
> If CONFIG_X86_X2APIC is undefined and CONFIG_KVM_GUEST is defined,
> there are undefined reference warning for x2apic_mode and check_x2apic
> etc since they are extern variables and just define under
> CONFIG_X86_X2APIC.

[...]

>
> If -cpu host,-x2apic we should go through mmio when writes xapic EOI.

Any ideas? :)

Regards,
Wanpeng Li