diff --git a/hw/i386/kvm/xen_evtchn.c b/hw/i386/kvm/xen_evtchn.c
index a73db5d2bc..e2ecee9a6f 100644
--- a/hw/i386/kvm/xen_evtchn.c
+++ b/hw/i386/kvm/xen_evtchn.c
@@ -26,6 +26,8 @@
 
 #include "hw/sysbus.h"
 #include "hw/xen/xen.h"
+#include "hw/i386/x86.h"
+#include "hw/irq.h"
 
 #include "xen_evtchn.h"
 #include "xen_overlay.h"
@@ -99,9 +101,12 @@ struct XenEvtchnState {
     uint64_t callback_param;
     bool evtchn_in_kernel;
 
+    QEMUBH *gsi_bh;
+
     QemuMutex port_lock;
     uint32_t nr_ports;
     XenEvtchnPort port_table[EVTCHN_2L_NR_CHANNELS];
+    qemu_irq gsis[GSI_NUM_PINS];
 };
 
 struct XenEvtchnState *xen_evtchn_singleton;
@@ -166,13 +171,42 @@ static const TypeInfo xen_evtchn_info = {
     .class_init    = xen_evtchn_class_init,
 };
 
+static void gsi_assert_bh(void *opaque)
+{
+    struct vcpu_info *vi = kvm_xen_get_vcpu_info_hva(0);
+    if (vi) {
+        xen_evtchn_set_callback_level(!!vi->evtchn_upcall_pending);
+    }
+}
+
 void xen_evtchn_create(void)
 {
     XenEvtchnState *s = XEN_EVTCHN(sysbus_create_simple(TYPE_XEN_EVTCHN,
                                                         -1, NULL));
+    int i;
+
     xen_evtchn_singleton = s;
 
     qemu_mutex_init(&s->port_lock);
+    s->gsi_bh = aio_bh_new(qemu_get_aio_context(), gsi_assert_bh, s);
+
+    for (i = 0; i < GSI_NUM_PINS; i++) {
+        sysbus_init_irq(SYS_BUS_DEVICE(s), &s->gsis[i]);
+    }
+}
+
+void xen_evtchn_connect_gsis(qemu_irq *system_gsis)
+{
+    XenEvtchnState *s = xen_evtchn_singleton;
+    int i;
+
+    if (!s) {
+        return;
+    }
+
+    for (i = 0; i < GSI_NUM_PINS; i++) {
+        sysbus_connect_irq(SYS_BUS_DEVICE(s), i, system_gsis[i]);
+    }
 }
 
 static void xen_evtchn_register_types(void)
@@ -182,6 +216,64 @@ static void xen_evtchn_register_types(void)
 
 type_init(xen_evtchn_register_types)
 
+void xen_evtchn_set_callback_level(int level)
+{
+    XenEvtchnState *s = xen_evtchn_singleton;
+    uint32_t param;
+
+    if (!s) {
+        return;
+    }
+
+    /*
+     * We get to this function in a number of ways:
+     *
+     *  • From I/O context, via PV backend drivers sending a notification to
+     *    the guest.
+     *
+     *  • From guest vCPU context, via loopback interdomain event channels
+     *    (or theoretically even IPIs but guests don't use those with GSI
+     *    delivery because that's pointless. We don't want a malicious guest
+     *    to be able to trigger a deadlock though, so we can't rule it out.)
+     *
+     *  • From guest vCPU context when the HVM_PARAM_CALLBACK_IRQ is being
+     *    configured.
+     *
+     *  • From guest vCPU context in the KVM exit handler, if the upcall
+     *    pending flag has been cleared and the GSI needs to be deasserted.
+     *
+     *  • Maybe in future, in an interrupt ack/eoi notifier when the GSI has
+     *    been acked in the irqchip.
+     *
+     * Whichever context we come from if we aren't already holding the BQL
+     * then e can't take it now, as we may already hold s->port_lock. So
+     * trigger the BH to set the IRQ for us instead of doing it immediately.
+     *
+     * In the HVM_PARAM_CALLBACK_IRQ and KVM exit handler cases, the caller
+     * will deliberately take the BQL because they want the change to take
+     * effect immediately. That just leaves interdomain loopback as the case
+     * which uses the BH.
+     */
+    if (!qemu_mutex_iothread_locked()) {
+        qemu_bh_schedule(s->gsi_bh);
+        return;
+    }
+
+    param = (uint32_t)s->callback_param;
+
+    switch (s->callback_param >> CALLBACK_VIA_TYPE_SHIFT) {
+    case HVM_PARAM_CALLBACK_TYPE_GSI:
+        if (param < GSI_NUM_PINS) {
+            qemu_set_irq(s->gsis[param], level);
+            if (level) {
+                /* Ensure the vCPU polls for deassertion */
+                kvm_xen_set_callback_asserted();
+            }
+        }
+        break;
+    }
+}
+
 int xen_evtchn_set_callback_param(uint64_t param)
 {
     XenEvtchnState *s = xen_evtchn_singleton;
@@ -207,6 +299,11 @@ int xen_evtchn_set_callback_param(uint64_t param)
         }
         break;
     }
+
+    case HVM_PARAM_CALLBACK_TYPE_GSI:
+        ret = 0;
+        break;
+
     default:
         ret = -ENOSYS;
         break;
diff --git a/hw/i386/kvm/xen_evtchn.h b/hw/i386/kvm/xen_evtchn.h
index 670f8b3f7d..1f9ffc3f94 100644
--- a/hw/i386/kvm/xen_evtchn.h
+++ b/hw/i386/kvm/xen_evtchn.h
@@ -12,9 +12,13 @@
 #ifndef QEMU_XEN_EVTCHN_H
 #define QEMU_XEN_EVTCHN_H
 
+#include "hw/sysbus.h"
+
 void xen_evtchn_create(void);
 int xen_evtchn_soft_reset(void);
 int xen_evtchn_set_callback_param(uint64_t param);
+void xen_evtchn_connect_gsis(qemu_irq *system_gsis);
+void xen_evtchn_set_callback_level(int level);
 
 void hmp_xen_event_inject(Monitor *mon, const QDict *qdict);
 void hmp_xen_event_list(Monitor *mon, const QDict *qdict);
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 8f668a5138..61a90c9e5b 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1308,6 +1308,12 @@ void pc_basic_device_init(struct PCMachineState *pcms,
     }
     *rtc_state = mc146818_rtc_init(isa_bus, 2000, rtc_irq);
 
+#ifdef CONFIG_XEN_EMU
+    if (xen_mode == XEN_EMULATE) {
+        xen_evtchn_connect_gsis(gsi);
+    }
+#endif
+
     qemu_register_boot_set(pc_boot_set, *rtc_state);
 
     if (!xen_enabled() &&
diff --git a/include/sysemu/kvm_xen.h b/include/sysemu/kvm_xen.h
index b2bcacd761..a32ee58852 100644
--- a/include/sysemu/kvm_xen.h
+++ b/include/sysemu/kvm_xen.h
@@ -22,6 +22,7 @@
 uint32_t kvm_xen_get_caps(void);
 void *kvm_xen_get_vcpu_info_hva(uint32_t vcpu_id);
 void kvm_xen_inject_vcpu_callback_vector(uint32_t vcpu_id, int type);
+void kvm_xen_set_callback_asserted(void);
 int kvm_xen_set_vcpu_virq(uint32_t vcpu_id, uint16_t virq, uint16_t port);
 
 #define kvm_xen_has_cap(cap) (!!(kvm_xen_get_caps() &           \
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index dba8732fc6..e8718c31e5 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1797,6 +1797,7 @@ typedef struct CPUArchState {
     uint64_t xen_vcpu_time_info_gpa;
     uint64_t xen_vcpu_runstate_gpa;
     uint8_t xen_vcpu_callback_vector;
+    bool xen_callback_asserted;
     uint16_t xen_virq[XEN_NR_VIRQS];
     uint64_t xen_singleshot_timer_ns;
 #endif
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index fa08cb6574..51ddf4bfa2 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -5415,6 +5415,19 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
     char str[256];
     KVMState *state;
 
+#ifdef CONFIG_XEN_EMU
+    /*
+     * If the callback is asserted as a GSI (or PCI INTx) then check if
+     * vcpu_info->evtchn_upcall_pending has been cleared, and deassert
+     * the callback IRQ if so. Ideally we could hook into the PIC/IOAPIC
+     * EOI and only resample then, exactly how the VFIO eventfd pairs
+     * are designed to work for level triggered interrupts.
+     */
+    if (cpu->env.xen_callback_asserted) {
+        kvm_xen_maybe_deassert_callback(cs);
+    }
+#endif
+
     switch (run->exit_reason) {
     case KVM_EXIT_HLT:
         DPRINTF("handle_hlt\n");
diff --git a/target/i386/kvm/xen-emu.c b/target/i386/kvm/xen-emu.c
index bc7426b90f..27e0555baf 100644
--- a/target/i386/kvm/xen-emu.c
+++ b/target/i386/kvm/xen-emu.c
@@ -311,6 +311,31 @@ void *kvm_xen_get_vcpu_info_hva(uint32_t vcpu_id)
     return X86_CPU(cs)->env.xen_vcpu_info_hva;
 }
 
+void kvm_xen_maybe_deassert_callback(CPUState *cs)
+{
+    CPUX86State *env = &X86_CPU(cs)->env;
+    struct vcpu_info *vi = env->xen_vcpu_info_hva;
+    if (!vi) {
+            return;
+    }
+
+    /* If the evtchn_upcall_pending flag is cleared, turn the GSI off. */
+    if (!vi->evtchn_upcall_pending) {
+        qemu_mutex_lock_iothread();
+        xen_evtchn_set_callback_level(0);
+        qemu_mutex_unlock_iothread();
+    }
+}
+
+void kvm_xen_set_callback_asserted(void)
+{
+    CPUState *cs = qemu_get_cpu(0);
+
+    if (cs) {
+        X86_CPU(cs)->env.xen_callback_asserted = true;
+    }
+}
+
 void kvm_xen_inject_vcpu_callback_vector(uint32_t vcpu_id, int type)
 {
     CPUState *cs = qemu_get_cpu(vcpu_id);
@@ -343,6 +368,13 @@ void kvm_xen_inject_vcpu_callback_vector(uint32_t vcpu_id, int type)
          */
         qemu_cpu_kick(cs);
         break;
+
+    case HVM_PARAM_CALLBACK_TYPE_GSI:
+    case HVM_PARAM_CALLBACK_TYPE_PCI_INTX:
+        if (vcpu_id == 0) {
+            xen_evtchn_set_callback_level(1);
+        }
+        break;
     }
 }
 
diff --git a/target/i386/kvm/xen-emu.h b/target/i386/kvm/xen-emu.h
index 452605699a..fe85e0b195 100644
--- a/target/i386/kvm/xen-emu.h
+++ b/target/i386/kvm/xen-emu.h
@@ -28,5 +28,6 @@ int kvm_xen_init_vcpu(CPUState *cs);
 int kvm_xen_handle_exit(X86CPU *cpu, struct kvm_xen_exit *exit);
 int kvm_put_xen_state(CPUState *cs);
 int kvm_get_xen_state(CPUState *cs);
+void kvm_xen_maybe_deassert_callback(CPUState *cs);
 
 #endif /* QEMU_I386_KVM_XEN_EMU_H */
