From: David Woodhouse <dwmw@amazon.co.uk>

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
---
 hw/i386/kvm/xen_evtchn.c  | 40 +++++++++++++++++++++++++++++++++++++++
 hw/i386/kvm/xen_evtchn.h  |  2 ++
 target/i386/kvm/xen-emu.c | 12 ++++++++++++
 3 files changed, 54 insertions(+)

diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c
index 744ce5ae11..e4535e14e8 100644
--- a/hw/i386/kvm/xen_evtchn.c
+++ b/hw/i386/kvm/xen_evtchn.c
@@ -789,6 +789,46 @@ int xen_evtchn_unmask_op(struct evtchn_unmask *unmask)
     return ret;
 }
 
+int xen_evtchn_bind_vcpu_op(struct evtchn_bind_vcpu *vcpu)
+{
+    XenEvtchnState *s = xen_evtchn_singleton;
+    XenEvtchnPort *p;
+    int ret = -EINVAL;
+
+    if (!s) {
+        return -ENOTSUP;
+    }
+
+    if (!valid_port(vcpu->port)) {
+        return -EINVAL;
+    }
+
+    if (!valid_vcpu(vcpu->vcpu)) {
+        return -ENOENT;
+    }
+
+    qemu_mutex_lock(&s->port_lock);
+
+    p = &s->port_table[vcpu->port];
+
+    if (p->type == EVTCHNSTAT_interdomain ||
+        p->type == EVTCHNSTAT_unbound ||
+        p->type == EVTCHNSTAT_pirq ||
+        (p->type == EVTCHNSTAT_virq && virq_is_global(p->type_val))) {
+        /*
+         * unmask_port() with do_unmask==false will just raise the event
+         * on the new vCPU if the port was already pending.
+         */
+        p->vcpu = vcpu->vcpu;
+        unmask_port(s, vcpu->port, false);
+        ret = 0;
+    }
+
+    qemu_mutex_unlock(&s->port_lock);
+
+    return ret;
+}
+
 int xen_evtchn_bind_virq_op(struct evtchn_bind_virq *virq)
 {
     XenEvtchnState *s = xen_evtchn_singleton;
diff --git a/hw/i386/kvm/xen_evtchn.h b/hw/i386/kvm/xen_evtchn.h
index 1ebc7580eb..486b031c82 100644
--- a/hw/i386/kvm/xen_evtchn.h
+++ b/hw/i386/kvm/xen_evtchn.h
@@ -23,6 +23,7 @@ struct evtchn_bind_ipi;
 struct evtchn_send;
 struct evtchn_alloc_unbound;
 struct evtchn_bind_interdomain;
+struct evtchn_bind_vcpu;
 int xen_evtchn_status_op(struct evtchn_status *status);
 int xen_evtchn_close_op(struct evtchn_close *close);
 int xen_evtchn_unmask_op(struct evtchn_unmask *unmask);
@@ -31,5 +32,6 @@ int xen_evtchn_bind_ipi_op(struct evtchn_bind_ipi *ipi);
 int xen_evtchn_send_op(struct evtchn_send *send);
 int xen_evtchn_alloc_unbound_op(struct evtchn_alloc_unbound *alloc);
 int xen_evtchn_bind_interdomain_op(struct evtchn_bind_interdomain *interdomain);
+int xen_evtchn_bind_vcpu_op(struct evtchn_bind_vcpu *vcpu);
 
 #endif /* QEMU_XEN_EVTCHN_H */
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index a855d05ce1..ed8ede6e3f 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -949,6 +949,18 @@ static bool kvm_xen_hcall_evtchn_op(struct kvm_xen_exit *exit, X86CPU *cpu,
         }
         break;
     }
+    case EVTCHNOP_bind_vcpu: {
+        struct evtchn_bind_vcpu vcpu;
+
+        qemu_build_assert(sizeof(vcpu) == 8);
+        if (kvm_copy_from_gva(cs, arg, &vcpu, sizeof(vcpu))) {
+            err = -EFAULT;
+            break;
+        }
+
+        err = xen_evtchn_bind_vcpu_op(&vcpu);
+        break;
+    }
     default:
         return false;
     }
-- 
2.39.0