return kvm_setup_async_pf(vcpu, gva, kvm_vcpu_gfn_to_hva(vcpu, gfn), &arch);
}
-bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu)
-{
- if (unlikely(!lapic_in_kernel(vcpu) ||
- kvm_event_needs_reinjection(vcpu) ||
- vcpu->arch.exception.pending))
- return false;
-
- if (!vcpu->arch.apf.delivery_as_pf_vmexit && is_guest_mode(vcpu))
- return false;
-
- return kvm_x86_ops->interrupt_allowed(vcpu);
-}
-
static bool try_async_pf(struct kvm_vcpu *vcpu, bool prefault, gfn_t gfn,
gva_t gva, kvm_pfn_t *pfn, bool write, bool *writable)
{
sizeof(u32));
}
+static bool kvm_can_deliver_async_pf(struct kvm_vcpu *vcpu)
+{
+ if (!vcpu->arch.apf.delivery_as_pf_vmexit && is_guest_mode(vcpu))
+ return false;
+
+ if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED) ||
+ (vcpu->arch.apf.send_user_only &&
+ kvm_x86_ops->get_cpl(vcpu) == 0))
+ return false;
+
+ return true;
+}
+
+bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu)
+{
+ if (unlikely(!lapic_in_kernel(vcpu) ||
+ kvm_event_needs_reinjection(vcpu) ||
+ vcpu->arch.exception.pending))
+ return false;
+
+ if (kvm_hlt_in_guest(vcpu->kvm) && !kvm_can_deliver_async_pf(vcpu))
+ return false;
+
+ /*
+ * If interrupts are off we cannot even use an artificial
+ * halt state.
+ */
+ return kvm_x86_ops->interrupt_allowed(vcpu);
+}
+
void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu,
struct kvm_async_pf *work)
{
trace_kvm_async_pf_not_present(work->arch.token, work->gva);
kvm_add_async_pf_gfn(vcpu, work->arch.gfn);
- if (!(vcpu->arch.apf.msr_val & KVM_ASYNC_PF_ENABLED) ||
- (vcpu->arch.apf.send_user_only &&
- kvm_x86_ops->get_cpl(vcpu) == 0))
- kvm_make_request(KVM_REQ_APF_HALT, vcpu);
- else if (!apf_put_user(vcpu, KVM_PV_REASON_PAGE_NOT_PRESENT)) {
+ if (kvm_can_deliver_async_pf(vcpu) &&
+ !apf_put_user(vcpu, KVM_PV_REASON_PAGE_NOT_PRESENT)) {
fault.vector = PF_VECTOR;
fault.error_code_valid = true;
fault.error_code = 0;
fault.address = work->arch.token;
fault.async_page_fault = true;
kvm_inject_page_fault(vcpu, &fault);
+ } else {
+ /*
+ * It is not possible to deliver a paravirtualized asynchronous
+ * page fault, but putting the guest in an artificial halt state
+ * can be beneficial nevertheless: if an interrupt arrives, we
+ * can deliver it timely and perhaps the guest will schedule
+ * another process. When the instruction that triggered a page
+ * fault is retried, hopefully the page will be ready in the host.
+ */
+ kvm_make_request(KVM_REQ_APF_HALT, vcpu);
}
}