From mboxrd@z Thu Jan  1 00:00:00 1970
From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Subject: Re: [PART1 RFC v2 06/10] svm: Add interrupt injection via AVIC
Date: Mon, 14 Mar 2016 16:41:34 +0700
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To: =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>
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Hi

On 03/09/2016 11:00 PM, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote:
> 2016-03-09 12:10+0100, Paolo Bonzini:
>> On 08/03/2016 22:54, Radim Kr=C4=8Dm=C3=A1=C5=99 wrote:
>>> 2016-03-07 16:36+0100, Paolo Bonzini:
>>>> On 04/03/2016 21:46, Suravee Suthikulpanit wrote:
>>>>> +static void svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec=
)
>>>>> +{
>>>>> +	struct vcpu_svm *svm =3D to_svm(vcpu);
>>>>> +
>>>>> +	kvm_lapic_set_vector(vec, avic_get_bk_page_entry(svm, APIC_IRR)=
);
>>>
>>> (I think that smp_mb here would make sense, even though we're fine =
now
>>>   thanks to re-checking vcpu->mode in kvm_vcpu_kick.
>>
>> Right, though only a smp_mb__after_atomic() is required (which is a
>> compiler barrier).  It is similarly required in vmx.
>
> True, kvm_lapic_set_vector uses a lock prefix.
>
> (I thought it behaves like atomic_set, which would require MFENCE for
>   correct ordering here ... I don't like smp_mb__after_atomic much
>   because of the discrepancy on some atomic operations.)
>

So, should i just use smb_mb() in this case?

Suravee.