Messages in this thread | | | Date | Mon, 02 Feb 2015 12:03:13 +0100 | From | Paolo Bonzini <> | Subject | Re: [PATCH v4 6/6] KVM: nVMX: Enable nested posted interrupt processing |
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On 28/01/2015 17:02, Wincy Van wrote: > +static int vmx_deliver_nested_posted_interrupt(struct kvm_vcpu *vcpu, > + int vector) > +{ > + if (is_guest_mode(vcpu) && > + vector == to_vmx(vcpu)->nested.posted_intr_nv && > + vcpu->mode == IN_GUEST_MODE) { > + /* the PIR and ON have been set by L1. */
What happens if there is a L2->L0->L2 exit on the target VCPU, and the guest exits before apic->send_IPI_mask sends the IPI?
The L1 hypervisor might "know" somehow that there cannot be a concurrent L2->L1->L2 exit, and not do the equivalent of KVM's
kvm_make_request(KVM_REQ_EVENT, vcpu);
after it sets ON.
So I think you have to do something like
static bool vmx_is_nested_posted_interrupt(struct kvm_vcpu *vcpu, int vector) { return (is_guest_mode(vcpu) && vector == to_vmx(vcpu)->nested.posted_intr_nv); }
and in vmx_deliver_posted_interrupt:
r = 0; if (!vmx_is_nested_posted_interrupt(vcpu, vector)) { if (pi_test_and_set_pir(vector, &vmx->pi_desc)) return;
r = pi_test_and_set_on(&vmx->pi_desc); } kvm_make_request(KVM_REQ_EVENT, vcpu); #ifdef CONFIG_SMP if (!r && (vcpu->mode == IN_GUEST_MODE)) apic->send_IPI_mask(get_cpu_mask(vcpu->cpu), POSTED_INTR_VECTOR); else #endif kvm_vcpu_kick(vcpu);
What do you think?
Paolo
> + apic->send_IPI_mask(get_cpu_mask(vcpu->cpu), > + POSTED_INTR_VECTOR); > + return 0; > + } > + return -1; > +}
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