Messages in this thread | | | Date | Wed, 9 Mar 2016 17:00:50 +0100 | From | Radim Krčmář <> | Subject | Re: [PART1 RFC v2 06/10] svm: Add interrupt injection via AVIC |
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2016-03-09 12:10+0100, Paolo Bonzini: > On 08/03/2016 22:54, Radim Krčmář 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 = 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.)
> Offtopic remark, kvm_make_request() and kvm_check_request() should > probably have a smp_wmb() and a smp_rmb().
Yeah, noted.
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