9 files changed, 278 insertions, 33 deletions

diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
index a2e7a0a7cf..8b3f664d85 100644
--- a/hw/vfio/Makefile.objs
+++ b/hw/vfio/Makefile.objs
@@ -6,4 +6,5 @@ obj-$(CONFIG_SOFTMMU) += platform.o
 obj-$(CONFIG_VFIO_XGMAC) += calxeda-xgmac.o
 obj-$(CONFIG_VFIO_AMD_XGBE) += amd-xgbe.o
 obj-$(CONFIG_SOFTMMU) += spapr.o
+obj-$(CONFIG_VFIO_AP) += ap.o
 endif
diff --git a/hw/vfio/amd-xgbe.c b/hw/vfio/amd-xgbe.c
index 0c4ec4ba25..ee64a3b4a2 100644
--- a/hw/vfio/amd-xgbe.c
+++ b/hw/vfio/amd-xgbe.c
@@ -20,6 +20,7 @@ static void amd_xgbe_realize(DeviceState *dev, Error **errp)
     VFIOAmdXgbeDeviceClass *k = VFIO_AMD_XGBE_DEVICE_GET_CLASS(dev);
 
     vdev->compat = g_strdup("amd,xgbe-seattle-v1a");
+    vdev->num_compat = 1;
 
     k->parent_realize(dev, errp);
 }
diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
new file mode 100644
index 0000000000..3962bb74e5
--- /dev/null
+++ b/hw/vfio/ap.c
@@ -0,0 +1,181 @@
+/*
+ * VFIO based AP matrix device assignment
+ *
+ * Copyright 2018 IBM Corp.
+ * Author(s): Tony Krowiak <akrowiak@linux.ibm.com>
+ *            Halil Pasic <pasic@linux.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or (at
+ * your option) any later version. See the COPYING file in the top-level
+ * directory.
+ */
+
+#include <linux/vfio.h>
+#include <sys/ioctl.h>
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "hw/sysbus.h"
+#include "hw/vfio/vfio.h"
+#include "hw/vfio/vfio-common.h"
+#include "hw/s390x/ap-device.h"
+#include "qemu/error-report.h"
+#include "qemu/queue.h"
+#include "qemu/option.h"
+#include "qemu/config-file.h"
+#include "cpu.h"
+#include "kvm_s390x.h"
+#include "sysemu/sysemu.h"
+#include "hw/s390x/ap-bridge.h"
+#include "exec/address-spaces.h"
+
+#define VFIO_AP_DEVICE_TYPE      "vfio-ap"
+
+typedef struct VFIOAPDevice {
+    APDevice apdev;
+    VFIODevice vdev;
+} VFIOAPDevice;
+
+#define VFIO_AP_DEVICE(obj) \
+        OBJECT_CHECK(VFIOAPDevice, (obj), VFIO_AP_DEVICE_TYPE)
+
+static void vfio_ap_compute_needs_reset(VFIODevice *vdev)
+{
+    vdev->needs_reset = false;
+}
+
+/*
+ * We don't need vfio_hot_reset_multi and vfio_eoi operations for
+ * vfio-ap device now.
+ */
+struct VFIODeviceOps vfio_ap_ops = {
+    .vfio_compute_needs_reset = vfio_ap_compute_needs_reset,
+};
+
+static void vfio_ap_put_device(VFIOAPDevice *vapdev)
+{
+    g_free(vapdev->vdev.name);
+    vfio_put_base_device(&vapdev->vdev);
+}
+
+static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp)
+{
+    GError *gerror = NULL;
+    char *symlink, *group_path;
+    int groupid;
+
+    symlink = g_strdup_printf("%s/iommu_group", vapdev->vdev.sysfsdev);
+    group_path = g_file_read_link(symlink, &gerror);
+    g_free(symlink);
+
+    if (!group_path) {
+        error_setg(errp, "%s: no iommu_group found for %s: %s",
+                   VFIO_AP_DEVICE_TYPE, vapdev->vdev.sysfsdev, gerror->message);
+        return NULL;
+    }
+
+    if (sscanf(basename(group_path), "%d", &groupid) != 1) {
+        error_setg(errp, "vfio: failed to read %s", group_path);
+        g_free(group_path);
+        return NULL;
+    }
+
+    g_free(group_path);
+
+    return vfio_get_group(groupid, &address_space_memory, errp);
+}
+
+static void vfio_ap_realize(DeviceState *dev, Error **errp)
+{
+    int ret;
+    char *mdevid;
+    Error *local_err = NULL;
+    VFIOGroup *vfio_group;
+    APDevice *apdev = AP_DEVICE(dev);
+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
+
+    vfio_group = vfio_ap_get_group(vapdev, &local_err);
+    if (!vfio_group) {
+        goto out_err;
+    }
+
+    vapdev->vdev.ops = &vfio_ap_ops;
+    vapdev->vdev.type = VFIO_DEVICE_TYPE_AP;
+    mdevid = basename(vapdev->vdev.sysfsdev);
+    vapdev->vdev.name = g_strdup_printf("%s", mdevid);
+    vapdev->vdev.dev = dev;
+
+    ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, &local_err);
+    if (ret) {
+        goto out_get_dev_err;
+    }
+
+    return;
+
+out_get_dev_err:
+    vfio_ap_put_device(vapdev);
+    vfio_put_group(vfio_group);
+out_err:
+    error_propagate(errp, local_err);
+}
+
+static void vfio_ap_unrealize(DeviceState *dev, Error **errp)
+{
+    APDevice *apdev = AP_DEVICE(dev);
+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
+    VFIOGroup *group = vapdev->vdev.group;
+
+    vfio_ap_put_device(vapdev);
+    vfio_put_group(group);
+}
+
+static Property vfio_ap_properties[] = {
+    DEFINE_PROP_STRING("sysfsdev", VFIOAPDevice, vdev.sysfsdev),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vfio_ap_reset(DeviceState *dev)
+{
+    int ret;
+    APDevice *apdev = AP_DEVICE(dev);
+    VFIOAPDevice *vapdev = VFIO_AP_DEVICE(apdev);
+
+    ret = ioctl(vapdev->vdev.fd, VFIO_DEVICE_RESET);
+    if (ret) {
+        error_report("%s: failed to reset %s device: %s", __func__,
+                     vapdev->vdev.name, strerror(ret));
+    }
+}
+
+static const VMStateDescription vfio_ap_vmstate = {
+    .name = VFIO_AP_DEVICE_TYPE,
+    .unmigratable = 1,
+};
+
+static void vfio_ap_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->props = vfio_ap_properties;
+    dc->vmsd = &vfio_ap_vmstate;
+    dc->desc = "VFIO-based AP device assignment";
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    dc->realize = vfio_ap_realize;
+    dc->unrealize = vfio_ap_unrealize;
+    dc->hotpluggable = false;
+    dc->reset = vfio_ap_reset;
+    dc->bus_type = TYPE_AP_BUS;
+}
+
+static const TypeInfo vfio_ap_info = {
+    .name = VFIO_AP_DEVICE_TYPE,
+    .parent = AP_DEVICE_TYPE,
+    .instance_size = sizeof(VFIOAPDevice),
+    .class_init = vfio_ap_class_init,
+};
+
+static void vfio_ap_type_init(void)
+{
+    type_register_static(&vfio_ap_info);
+}
+
+type_init(vfio_ap_type_init)
diff --git a/hw/vfio/calxeda-xgmac.c b/hw/vfio/calxeda-xgmac.c
index 24cee6d065..e7767c4b02 100644
--- a/hw/vfio/calxeda-xgmac.c
+++ b/hw/vfio/calxeda-xgmac.c
@@ -20,6 +20,7 @@ static void calxeda_xgmac_realize(DeviceState *dev, Error **errp)
     VFIOCalxedaXgmacDeviceClass *k = VFIO_CALXEDA_XGMAC_DEVICE_GET_CLASS(dev);
 
     vdev->compat = g_strdup("calxeda,hb-xgmac");
+    vdev->num_compat = 1;
 
     k->parent_realize(dev, errp);
 }
diff --git a/hw/vfio/display.c b/hw/vfio/display.c
index 59c0e5d1d7..dead30e626 100644
--- a/hw/vfio/display.c
+++ b/hw/vfio/display.c
@@ -124,6 +124,9 @@ static void vfio_display_dmabuf_update(void *opaque)
 
     primary = vfio_display_get_dmabuf(vdev, DRM_PLANE_TYPE_PRIMARY);
     if (primary == NULL) {
+        if (dpy->ramfb) {
+            ramfb_display_update(dpy->con, dpy->ramfb);
+        }
         return;
     }
 
@@ -181,6 +184,9 @@ static int vfio_display_dmabuf_init(VFIOPCIDevice *vdev, Error **errp)
     vdev->dpy->con = graphic_console_init(DEVICE(vdev), 0,
                                           &vfio_display_dmabuf_ops,
                                           vdev);
+    if (vdev->enable_ramfb) {
+        vdev->dpy->ramfb = ramfb_setup(errp);
+    }
     return 0;
 }
 
@@ -228,6 +234,9 @@ static void vfio_display_region_update(void *opaque)
         return;
     }
     if (!plane.drm_format || !plane.size) {
+        if (dpy->ramfb) {
+            ramfb_display_update(dpy->con, dpy->ramfb);
+        }
         return;
     }
     format = qemu_drm_format_to_pixman(plane.drm_format);
@@ -300,6 +309,9 @@ static int vfio_display_region_init(VFIOPCIDevice *vdev, Error **errp)
     vdev->dpy->con = graphic_console_init(DEVICE(vdev), 0,
                                           &vfio_display_region_ops,
                                           vdev);
+    if (vdev->enable_ramfb) {
+        vdev->dpy->ramfb = ramfb_setup(errp);
+    }
     return 0;
 }
 
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index 481fd08df7..eae31c74d6 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -1670,7 +1670,7 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
      * but also no point in us enabling VGA if disabled in hardware.
      */
     if (!(gmch & 0x2) && !vdev->vga && vfio_populate_vga(vdev, &err)) {
-        error_reportf_err(err, ERR_PREFIX, vdev->vbasedev.name);
+        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
         error_report("IGD device %s failed to enable VGA access, "
                      "legacy mode disabled", vdev->vbasedev.name);
         goto out;
@@ -1696,7 +1696,7 @@ static void vfio_probe_igd_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     ret = vfio_pci_igd_opregion_init(vdev, opregion, &err);
     if (ret) {
         error_append_hint(&err, "IGD legacy mode disabled\n");
-        error_reportf_err(err, ERR_PREFIX, vdev->vbasedev.name);
+        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
         goto out;
     }
 
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 866f0deeb7..5c7bd96984 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -37,6 +37,9 @@
 
 #define MSIX_CAP_LENGTH 12
 
+#define TYPE_VFIO_PCI "vfio-pci"
+#define PCI_VFIO(obj)    OBJECT_CHECK(VFIOPCIDevice, obj, TYPE_VFIO_PCI)
+
 static void vfio_disable_interrupts(VFIOPCIDevice *vdev);
 static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled);
 
@@ -222,7 +225,7 @@ static void vfio_intx_disable_kvm(VFIOPCIDevice *vdev)
 
 static void vfio_intx_update(PCIDevice *pdev)
 {
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(pdev);
     PCIINTxRoute route;
     Error *err = NULL;
 
@@ -249,7 +252,7 @@ static void vfio_intx_update(PCIDevice *pdev)
 
     vfio_intx_enable_kvm(vdev, &err);
     if (err) {
-        error_reportf_err(err, WARN_PREFIX, vdev->vbasedev.name);
+        warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 
     /* Re-enable the interrupt in cased we missed an EOI */
@@ -314,7 +317,7 @@ static int vfio_intx_enable(VFIOPCIDevice *vdev, Error **errp)
 
     vfio_intx_enable_kvm(vdev, &err);
     if (err) {
-        error_reportf_err(err, WARN_PREFIX, vdev->vbasedev.name);
+        warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 
     vdev->interrupt = VFIO_INT_INTx;
@@ -477,7 +480,7 @@ static void vfio_update_kvm_msi_virq(VFIOMSIVector *vector, MSIMessage msg,
 static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
                                    MSIMessage *msg, IOHandler *handler)
 {
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(pdev);
     VFIOMSIVector *vector;
     int ret;
 
@@ -574,7 +577,7 @@ static int vfio_msix_vector_use(PCIDevice *pdev,
 
 static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr)
 {
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(pdev);
     VFIOMSIVector *vector = &vdev->msi_vectors[nr];
 
     trace_vfio_msix_vector_release(vdev->vbasedev.name, nr);
@@ -742,7 +745,7 @@ static void vfio_msi_disable_common(VFIOPCIDevice *vdev)
 
     vfio_intx_enable(vdev, &err);
     if (err) {
-        error_reportf_err(err, ERR_PREFIX, vdev->vbasedev.name);
+        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 }
 
@@ -1086,7 +1089,7 @@ static const MemoryRegionOps vfio_vga_ops = {
  */
 static void vfio_sub_page_bar_update_mapping(PCIDevice *pdev, int bar)
 {
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(pdev);
     VFIORegion *region = &vdev->bars[bar].region;
     MemoryRegion *mmap_mr, *region_mr, *base_mr;
     PCIIORegion *r;
@@ -1132,7 +1135,7 @@ static void vfio_sub_page_bar_update_mapping(PCIDevice *pdev, int bar)
  */
 uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
 {
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(pdev);
     uint32_t emu_bits = 0, emu_val = 0, phys_val = 0, val;
 
     memcpy(&emu_bits, vdev->emulated_config_bits + addr, len);
@@ -1165,7 +1168,7 @@ uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
 void vfio_pci_write_config(PCIDevice *pdev,
                            uint32_t addr, uint32_t val, int len)
 {
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(pdev);
     uint32_t val_le = cpu_to_le32(val);
 
     trace_vfio_pci_write_config(vdev->vbasedev.name, addr, val, len);
@@ -1280,8 +1283,7 @@ static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
         if (ret == -ENOTSUP) {
             return 0;
         }
-        error_prepend(&err, "msi_init failed: ");
-        error_propagate(errp, err);
+        error_propagate_prepend(errp, err, "msi_init failed: ");
         return ret;
     }
     vdev->msi_cap_size = 0xa + (msi_maskbit ? 0xa : 0) + (msi_64bit ? 0x4 : 0);
@@ -1555,7 +1557,7 @@ static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos, Error **errp)
                     &err);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
-            error_report_err(err);
+            warn_report_err(err);
             return 0;
         }
 
@@ -2194,7 +2196,7 @@ static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
 
     vfio_intx_enable(vdev, &err);
     if (err) {
-        error_reportf_err(err, ERR_PREFIX, vdev->vbasedev.name);
+        error_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 
     for (nr = 0; nr < PCI_NUM_REGIONS - 1; ++nr) {
@@ -2588,9 +2590,9 @@ static void vfio_populate_device(VFIOPCIDevice *vdev, Error **errp)
     } else if (irq_info.count == 1) {
         vdev->pci_aer = true;
     } else {
-        error_report(WARN_PREFIX
-                     "Could not enable error recovery for the device",
-                     vbasedev->name);
+        warn_report(VFIO_MSG_PREFIX
+                    "Could not enable error recovery for the device",
+                    vbasedev->name);
     }
 }
 
@@ -2715,7 +2717,7 @@ static void vfio_req_notifier_handler(void *opaque)
 
     qdev_unplug(&vdev->pdev.qdev, &err);
     if (err) {
-        error_reportf_err(err, WARN_PREFIX, vdev->vbasedev.name);
+        warn_reportf_err(err, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     }
 }
 
@@ -2801,7 +2803,7 @@ static void vfio_unregister_req_notifier(VFIOPCIDevice *vdev)
 
 static void vfio_realize(PCIDevice *pdev, Error **errp)
 {
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(pdev);
     VFIODevice *vbasedev_iter;
     VFIOGroup *group;
     char *tmp, *subsys, group_path[PATH_MAX], *group_name;
@@ -2828,7 +2830,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
 
     if (stat(vdev->vbasedev.sysfsdev, &st) < 0) {
         error_setg_errno(errp, errno, "no such host device");
-        error_prepend(errp, ERR_PREFIX, vdev->vbasedev.sysfsdev);
+        error_prepend(errp, VFIO_MSG_PREFIX, vdev->vbasedev.sysfsdev);
         return;
     }
 
@@ -3067,6 +3069,10 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
             goto out_teardown;
         }
     }
+    if (vdev->enable_ramfb && vdev->dpy == NULL) {
+        error_setg(errp, "ramfb=on requires display=on");
+        goto out_teardown;
+    }
 
     vfio_register_err_notifier(vdev);
     vfio_register_req_notifier(vdev);
@@ -3079,13 +3085,12 @@ out_teardown:
     vfio_teardown_msi(vdev);
     vfio_bars_exit(vdev);
 error:
-    error_prepend(errp, ERR_PREFIX, vdev->vbasedev.name);
+    error_prepend(errp, VFIO_MSG_PREFIX, vdev->vbasedev.name);
 }
 
 static void vfio_instance_finalize(Object *obj)
 {
-    PCIDevice *pci_dev = PCI_DEVICE(obj);
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pci_dev);
+    VFIOPCIDevice *vdev = PCI_VFIO(obj);
     VFIOGroup *group = vdev->vbasedev.group;
 
     vfio_display_finalize(vdev);
@@ -3105,7 +3110,7 @@ static void vfio_instance_finalize(Object *obj)
 
 static void vfio_exitfn(PCIDevice *pdev)
 {
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(pdev);
 
     vfio_unregister_req_notifier(vdev);
     vfio_unregister_err_notifier(vdev);
@@ -3120,8 +3125,7 @@ static void vfio_exitfn(PCIDevice *pdev)
 
 static void vfio_pci_reset(DeviceState *dev)
 {
-    PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, dev);
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
+    VFIOPCIDevice *vdev = PCI_VFIO(dev);
 
     trace_vfio_pci_reset(vdev->vbasedev.name);
 
@@ -3161,7 +3165,7 @@ post_reset:
 static void vfio_instance_init(Object *obj)
 {
     PCIDevice *pci_dev = PCI_DEVICE(obj);
-    VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, PCI_DEVICE(obj));
+    VFIOPCIDevice *vdev = PCI_VFIO(obj);
 
     device_add_bootindex_property(obj, &vdev->bootindex,
                                   "bootindex", NULL,
@@ -3245,7 +3249,7 @@ static void vfio_pci_dev_class_init(ObjectClass *klass, void *data)
 }
 
 static const TypeInfo vfio_pci_dev_info = {
-    .name = "vfio-pci",
+    .name = TYPE_VFIO_PCI,
     .parent = TYPE_PCI_DEVICE,
     .instance_size = sizeof(VFIOPCIDevice),
     .class_init = vfio_pci_dev_class_init,
@@ -3258,9 +3262,30 @@ static const TypeInfo vfio_pci_dev_info = {
     },
 };
 
+static Property vfio_pci_dev_nohotplug_properties[] = {
+    DEFINE_PROP_BOOL("ramfb", VFIOPCIDevice, enable_ramfb, false),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void vfio_pci_nohotplug_dev_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->props = vfio_pci_dev_nohotplug_properties;
+    dc->hotpluggable = false;
+}
+
+static const TypeInfo vfio_pci_nohotplug_dev_info = {
+    .name = "vfio-pci-nohotplug",
+    .parent = "vfio-pci",
+    .instance_size = sizeof(VFIOPCIDevice),
+    .class_init = vfio_pci_nohotplug_dev_class_init,
+};
+
 static void register_vfio_pci_dev_type(void)
 {
     type_register_static(&vfio_pci_dev_info);
+    type_register_static(&vfio_pci_nohotplug_dev_info);
 }
 
 type_init(register_vfio_pci_dev_type)
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 52b065421a..b1ae4c0754 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -165,6 +165,7 @@ typedef struct VFIOPCIDevice {
     bool no_geforce_quirks;
     bool no_kvm_ioeventfd;
     bool no_vfio_ioeventfd;
+    bool enable_ramfb;
     VFIODisplay *dpy;
 } VFIOPCIDevice;
 
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index 57c4a0ee2b..398db38f14 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -655,10 +655,32 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
         goto out;
     }
 
+    if (!vdev->compat) {
+        GError *gerr = NULL;
+        gchar *contents;
+        gsize length;
+        char *path;
+
+        path = g_strdup_printf("%s/of_node/compatible", vbasedev->sysfsdev);
+        if (!g_file_get_contents(path, &contents, &length, &gerr)) {
+            error_setg(errp, "%s", gerr->message);
+            g_error_free(gerr);
+            g_free(path);
+            return;
+        }
+        g_free(path);
+        vdev->compat = contents;
+        for (vdev->num_compat = 0; length; vdev->num_compat++) {
+            size_t skip = strlen(contents) + 1;
+            contents += skip;
+            length -= skip;
+        }
+    }
+
     for (i = 0; i < vbasedev->num_regions; i++) {
         if (vfio_region_mmap(vdev->regions[i])) {
-            error_report("%s mmap unsupported. Performance may be slow",
-                         memory_region_name(vdev->regions[i]->mem));
+            warn_report("%s mmap unsupported, performance may be slow",
+                        memory_region_name(vdev->regions[i]->mem));
         }
         sysbus_init_mmio(sbdev, vdev->regions[i]->mem);
     }
@@ -668,7 +690,7 @@ out:
     }
 
     if (vdev->vbasedev.name) {
-        error_prepend(errp, ERR_PREFIX, vdev->vbasedev.name);
+        error_prepend(errp, VFIO_MSG_PREFIX, vdev->vbasedev.name);
     } else {
         error_prepend(errp, "vfio error: ");
     }
@@ -700,6 +722,8 @@ static void vfio_platform_class_init(ObjectClass *klass, void *data)
     dc->desc = "VFIO-based platform device assignment";
     sbc->connect_irq_notifier = vfio_start_irqfd_injection;
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    /* Supported by TYPE_VIRT_MACHINE */
+    dc->user_creatable = true;
 }
 
 static const TypeInfo vfio_platform_dev_info = {
@@ -708,7 +732,6 @@ static const TypeInfo vfio_platform_dev_info = {
     .instance_size = sizeof(VFIOPlatformDevice),
     .class_init = vfio_platform_class_init,
     .class_size = sizeof(VFIOPlatformDeviceClass),
-    .abstract   = true,
 };
 
 static void register_vfio_platform_dev_type(void)