diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c
index 316b969b5c..e15c104175 100644
--- a/hw/s390x/s390-pci-bus.c
+++ b/hw/s390x/s390-pci-bus.c
@@ -189,7 +189,10 @@ void s390_pci_sclp_deconfigure(SCCB *sccb)
         rc = SCLP_RC_NO_ACTION_REQUIRED;
         break;
     default:
-        if (pbdev->summary_ind) {
+        if (pbdev->interp) {
+            /* Interpreted devices were using interrupt forwarding */
+            s390_pci_set_aif(pbdev, NULL, false, pbdev->forwarding_assist);
+        } else if (pbdev->summary_ind) {
             pci_dereg_irqs(pbdev);
         }
         if (pbdev->iommu->enabled) {
@@ -981,6 +984,11 @@ static int s390_pci_interp_plug(S390pciState *s, S390PCIBusDevice *pbdev)
         return rc;
     }
 
+    rc = s390_pci_probe_aif(pbdev);
+    if (rc) {
+        return rc;
+    }
+
     rc = s390_pci_update_passthrough_fh(pbdev);
     if (rc) {
         return rc;
@@ -1084,6 +1092,7 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
                 } else {
                     DPRINTF("zPCI interpretation facilities missing.\n");
                     pbdev->interp = false;
+                    pbdev->forwarding_assist = false;
                 }
             }
             pbdev->iommu->dma_limit = s390_pci_start_dma_count(s, pbdev);
@@ -1092,11 +1101,13 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
             if (!pbdev->interp) {
                 /* Do vfio passthrough but intercept for I/O */
                 pbdev->fh |= FH_SHM_VFIO;
+                pbdev->forwarding_assist = false;
             }
         } else {
             pbdev->fh |= FH_SHM_EMUL;
             /* Always intercept emulated devices */
             pbdev->interp = false;
+            pbdev->forwarding_assist = false;
         }
 
         if (s390_pci_msix_init(pbdev) && !pbdev->interp) {
@@ -1246,7 +1257,10 @@ static void s390_pcihost_reset(DeviceState *dev)
     /* Process all pending unplug requests */
     QTAILQ_FOREACH_SAFE(pbdev, &s->zpci_devs, link, next) {
         if (pbdev->unplug_requested) {
-            if (pbdev->summary_ind) {
+            if (pbdev->interp) {
+                /* Interpreted devices were using interrupt forwarding */
+                s390_pci_set_aif(pbdev, NULL, false, pbdev->forwarding_assist);
+            } else if (pbdev->summary_ind) {
                 pci_dereg_irqs(pbdev);
             }
             if (pbdev->iommu->enabled) {
@@ -1384,7 +1398,10 @@ static void s390_pci_device_reset(DeviceState *dev)
         break;
     }
 
-    if (pbdev->summary_ind) {
+    if (pbdev->interp) {
+        /* Interpreted devices were using interrupt forwarding */
+        s390_pci_set_aif(pbdev, NULL, false, pbdev->forwarding_assist);
+    } else if (pbdev->summary_ind) {
         pci_dereg_irqs(pbdev);
     }
     if (pbdev->iommu->enabled) {
@@ -1430,6 +1447,8 @@ static Property s390_pci_device_properties[] = {
     DEFINE_PROP_S390_PCI_FID("fid", S390PCIBusDevice, fid),
     DEFINE_PROP_STRING("target", S390PCIBusDevice, target),
     DEFINE_PROP_BOOL("interpret", S390PCIBusDevice, interp, true),
+    DEFINE_PROP_BOOL("forwarding_assist", S390PCIBusDevice, forwarding_assist,
+                     true),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
index e9a0dc12e4..dae2012646 100644
--- a/hw/s390x/s390-pci-inst.c
+++ b/hw/s390x/s390-pci-inst.c
@@ -1111,6 +1111,46 @@ static void fmb_update(void *opaque)
     timer_mod(pbdev->fmb_timer, t + pbdev->pci_group->zpci_group.mui);
 }
 
+static int mpcifc_reg_int_interp(S390PCIBusDevice *pbdev, ZpciFib *fib)
+{
+    int rc;
+
+    /* Interpreted devices must also use interrupt forwarding */
+    rc = s390_pci_get_aif(pbdev, false, pbdev->forwarding_assist);
+    if (rc) {
+        DPRINTF("Bad interrupt forwarding state\n");
+        return rc;
+    }
+
+    rc = s390_pci_set_aif(pbdev, fib, true, pbdev->forwarding_assist);
+    if (rc) {
+        DPRINTF("Failed to enable interrupt forwarding\n");
+        return rc;
+    }
+
+    return 0;
+}
+
+static int mpcifc_dereg_int_interp(S390PCIBusDevice *pbdev, ZpciFib *fib)
+{
+    int rc;
+
+    /* Interpreted devices were using interrupt forwarding */
+    rc = s390_pci_get_aif(pbdev, true, pbdev->forwarding_assist);
+    if (rc) {
+        DPRINTF("Bad interrupt forwarding state\n");
+        return rc;
+    }
+
+    rc = s390_pci_set_aif(pbdev, fib, false, pbdev->forwarding_assist);
+    if (rc) {
+        DPRINTF("Failed to disable interrupt forwarding\n");
+        return rc;
+    }
+
+    return 0;
+}
+
 int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
                         uintptr_t ra)
 {
@@ -1165,7 +1205,12 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
 
     switch (oc) {
     case ZPCI_MOD_FC_REG_INT:
-        if (pbdev->summary_ind) {
+        if (pbdev->interp) {
+            if (mpcifc_reg_int_interp(pbdev, &fib)) {
+                cc = ZPCI_PCI_LS_ERR;
+                s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
+            }
+        } else if (pbdev->summary_ind) {
             cc = ZPCI_PCI_LS_ERR;
             s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
         } else if (reg_irqs(env, pbdev, fib)) {
@@ -1174,7 +1219,12 @@ int mpcifc_service_call(S390CPU *cpu, uint8_t r1, uint64_t fiba, uint8_t ar,
         }
         break;
     case ZPCI_MOD_FC_DEREG_INT:
-        if (!pbdev->summary_ind) {
+        if (pbdev->interp) {
+            if (mpcifc_dereg_int_interp(pbdev, &fib)) {
+                cc = ZPCI_PCI_LS_ERR;
+                s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
+            }
+        } else if (!pbdev->summary_ind) {
             cc = ZPCI_PCI_LS_ERR;
             s390_set_status_code(env, r1, ZPCI_MOD_ST_SEQUENCE);
         } else {
diff --git a/hw/s390x/s390-pci-vfio.c b/hw/s390x/s390-pci-vfio.c
index 2cab3a9e89..381cbb437a 100644
--- a/hw/s390x/s390-pci-vfio.c
+++ b/hw/s390x/s390-pci-vfio.c
@@ -149,6 +149,87 @@ int s390_pci_update_passthrough_fh(S390PCIBusDevice *pbdev)
     return 0;
 }
 
+int s390_pci_probe_aif(S390PCIBusDevice *pbdev)
+{
+    VFIOPCIDevice *vdev = VFIO_PCI(pbdev->pdev);
+    struct vfio_device_feature feat = {
+        .argsz = sizeof(struct vfio_device_feature),
+        .flags = VFIO_DEVICE_FEATURE_PROBE + VFIO_DEVICE_FEATURE_ZPCI_AIF
+    };
+
+    return ioctl(vdev->vbasedev.fd, VFIO_DEVICE_FEATURE, &feat);
+}
+
+int s390_pci_set_aif(S390PCIBusDevice *pbdev, ZpciFib *fib, bool enable,
+                     bool assist)
+{
+    VFIOPCIDevice *vdev = VFIO_PCI(pbdev->pdev);
+    struct vfio_device_zpci_aif *data;
+    int size = sizeof(struct vfio_device_feature) + sizeof(*data);
+    g_autofree struct vfio_device_feature *feat = g_malloc0(size);
+
+    feat->argsz = size;
+    feat->flags = VFIO_DEVICE_FEATURE_SET + VFIO_DEVICE_FEATURE_ZPCI_AIF;
+
+    data = (struct vfio_device_zpci_aif *)&feat->data;
+    if (enable) {
+        data->flags = VFIO_DEVICE_ZPCI_FLAG_AIF_FLOAT;
+        if (!pbdev->forwarding_assist) {
+            data->flags |= VFIO_DEVICE_ZPCI_FLAG_AIF_HOST;
+        }
+        /* Fill in the guest fib info */
+        data->ibv = fib->aibv;
+        data->sb = fib->aisb;
+        data->noi = FIB_DATA_NOI(fib->data);
+        data->isc = FIB_DATA_ISC(fib->data);
+        data->sbo = FIB_DATA_AISBO(fib->data);
+    } else {
+        data->flags = 0;
+    }
+
+    return ioctl(vdev->vbasedev.fd, VFIO_DEVICE_FEATURE, feat);
+}
+
+int s390_pci_get_aif(S390PCIBusDevice *pbdev, bool enabled,
+                     bool forwarding_assist)
+{
+    VFIOPCIDevice *vdev = VFIO_PCI(pbdev->pdev);
+    struct vfio_device_zpci_aif *data;
+    int size = sizeof(struct vfio_device_feature) + sizeof(*data);
+    g_autofree struct vfio_device_feature *feat = g_malloc0(size);
+    int rc;
+
+    feat->argsz = size;
+    feat->flags = VFIO_DEVICE_FEATURE_GET + VFIO_DEVICE_FEATURE_ZPCI_AIF;
+
+    rc = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_FEATURE, feat);
+    if (rc) {
+        return rc;
+    }
+
+    /* Ensure that both kernel and QEMU agree on whether AIF is enabled */
+    data = (struct vfio_device_zpci_aif *)&feat->data;
+    if (enabled && (!(data->flags & VFIO_DEVICE_ZPCI_FLAG_AIF_FLOAT))) {
+        rc = -EINVAL;
+    } else if (!enabled && (data->flags & VFIO_DEVICE_ZPCI_FLAG_AIF_FLOAT)) {
+        rc = -EINVAL;
+    }
+
+    /*
+     * If AIF is enabled, ensure that kernel and QEMU agree on whether host
+     * delivery is being forced
+     */
+    if (enabled && forwarding_assist &&
+        (data->flags & VFIO_DEVICE_ZPCI_FLAG_AIF_HOST)) {
+        rc = -EINVAL;
+    } else if (enabled && (!forwarding_assist) &&
+               (!(data->flags & VFIO_DEVICE_ZPCI_FLAG_AIF_HOST))) {
+        rc = -EINVAL;
+    }
+
+    return rc;
+}
+
 static void s390_pci_read_base(S390PCIBusDevice *pbdev,
                                struct vfio_device_info *info)
 {
diff --git a/include/hw/s390x/s390-pci-bus.h b/include/hw/s390x/s390-pci-bus.h
index a9843dfe97..5b09f0cf2f 100644
--- a/include/hw/s390x/s390-pci-bus.h
+++ b/include/hw/s390x/s390-pci-bus.h
@@ -351,6 +351,7 @@ struct S390PCIBusDevice {
     bool pci_unplug_request_processed;
     bool unplug_requested;
     bool interp;
+    bool forwarding_assist;
     QTAILQ_ENTRY(S390PCIBusDevice) link;
 };
 
diff --git a/include/hw/s390x/s390-pci-vfio.h b/include/hw/s390x/s390-pci-vfio.h
index 33e82ea370..7096d4a0b0 100644
--- a/include/hw/s390x/s390-pci-vfio.h
+++ b/include/hw/s390x/s390-pci-vfio.h
@@ -13,6 +13,7 @@
 #define HW_S390_PCI_VFIO_H
 
 #include "hw/s390x/s390-pci-bus.h"
+#include "hw/s390x/s390-pci-inst.h"
 #include CONFIG_DEVICES
 
 #ifdef CONFIG_VFIO
@@ -23,6 +24,12 @@ void s390_pci_end_dma_count(S390pciState *s, S390PCIDMACount *cnt);
 int s390_pci_probe_interp(S390PCIBusDevice *pbdev);
 int s390_pci_set_interp(S390PCIBusDevice *pbdev, bool enable);
 int s390_pci_update_passthrough_fh(S390PCIBusDevice *pbdev);
+int s390_pci_probe_aif(S390PCIBusDevice *pbdev);
+int s390_pci_set_aif(S390PCIBusDevice *pbdev, ZpciFib *fib, bool enable,
+                     bool assist);
+int s390_pci_get_aif(S390PCIBusDevice *pbdev, bool enabled,
+                     bool forwarding_assist);
+
 void s390_pci_get_clp_info(S390PCIBusDevice *pbdev);
 #else
 static inline bool s390_pci_update_dma_avail(int fd, unsigned int *avail)
@@ -48,6 +55,20 @@ static inline int s390_pci_update_passthrough_fh(S390PCIBusDevice *pbdev)
 {
     return -EINVAL;
 }
+static inline int s390_pci_probe_aif(S390PCIBusDevice *pbdev)
+{
+    return -EINVAL;
+}
+static inline int s390_pci_set_aif(S390PCIBusDevice *pbdev, ZpciFib *fib,
+                                   bool enable, bool assist)
+{
+    return -EINVAL;
+}
+static inline int s390_pci_get_aif(S390PCIBusDevice *pbdev, bool enabled,
+                                   bool forwarding_assist)
+{
+    return -EINVAL;
+}
 static inline void s390_pci_get_clp_info(S390PCIBusDevice *pbdev) { }
 #endif
 
