diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c
index 7d8a023..1ab6d97 100644
--- a/hw/xen/xen-host-pci-device.c
+++ b/hw/xen/xen-host-pci-device.c
@@ -43,13 +43,14 @@ static int xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
         /* The output is truncated, or some other error was encountered */
         return -ENODEV;
     }
+
     return 0;
 }
 
 
 /* This size should be enough to read the first 7 lines of a resource file */
 #define XEN_HOST_PCI_RESOURCE_BUFFER_SIZE 400
-static int xen_host_pci_get_resource(XenHostPCIDevice *d)
+static void xen_host_pci_get_resource(XenHostPCIDevice *d, Error **errp)
 {
     int i, rc, fd;
     char path[PATH_MAX];
@@ -60,23 +61,24 @@ static int xen_host_pci_get_resource(XenHostPCIDevice *d)
 
     rc = xen_host_pci_sysfs_path(d, "resource", path, sizeof (path));
     if (rc) {
-        return rc;
+        error_setg_errno(errp, errno, "snprintf err");
+        return;
     }
+
     fd = open(path, O_RDONLY);
     if (fd == -1) {
-        XEN_HOST_PCI_LOG("Error: Can't open %s: %s\n", path, strerror(errno));
-        return -errno;
+        error_setg_errno(errp, errno, "open err");
+        return;
     }
 
     do {
         rc = read(fd, &buf, sizeof (buf) - 1);
         if (rc < 0 && errno != EINTR) {
-            rc = -errno;
+            error_setg_errno(errp, errno, "read err");
             goto out;
         }
     } while (rc < 0);
     buf[rc] = 0;
-    rc = 0;
 
     s = buf;
     for (i = 0; i < PCI_NUM_REGIONS; i++) {
@@ -129,20 +131,20 @@ static int xen_host_pci_get_resource(XenHostPCIDevice *d)
             d->rom.bus_flags = flags & IORESOURCE_BITS;
         }
     }
+
     if (i != PCI_NUM_REGIONS) {
         /* Invalid format or input to short */
-        rc = -ENODEV;
+        error_setg(errp, "Invalid format or input to short");
     }
 
 out:
     close(fd);
-    return rc;
 }
 
 /* This size should be enough to read a long from a file */
 #define XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE 22
 static int xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
-                                  unsigned int *pvalue, int base)
+                                  unsigned int *pvalue, int base, Error **errp)
 {
     char path[PATH_MAX];
     char buf[XEN_HOST_PCI_GET_VALUE_BUFFER_SIZE];
@@ -152,30 +154,38 @@ static int xen_host_pci_get_value(XenHostPCIDevice *d, const char *name,
 
     rc = xen_host_pci_sysfs_path(d, name, path, sizeof (path));
     if (rc) {
+        error_setg_errno(errp, errno, "snprintf err");
         return rc;
     }
+
     fd = open(path, O_RDONLY);
     if (fd == -1) {
-        XEN_HOST_PCI_LOG("Error: Can't open %s: %s\n", path, strerror(errno));
+        error_setg_errno(errp, errno, "open err");
         return -errno;
     }
+
     do {
         rc = read(fd, &buf, sizeof (buf) - 1);
         if (rc < 0 && errno != EINTR) {
+            error_setg_errno(errp, errno, "read err");
             rc = -errno;
             goto out;
         }
     } while (rc < 0);
+
     buf[rc] = 0;
     value = strtol(buf, &endptr, base);
     if (endptr == buf || *endptr != '\n') {
+        error_setg(errp, "format invalid");
         rc = -1;
     } else if ((value == LONG_MIN || value == LONG_MAX) && errno == ERANGE) {
+        error_setg_errno(errp, errno, "strtol err");
         rc = -errno;
     } else {
         rc = 0;
         *pvalue = value;
     }
+
 out:
     close(fd);
     return rc;
@@ -183,16 +193,18 @@ out:
 
 static inline int xen_host_pci_get_hex_value(XenHostPCIDevice *d,
                                              const char *name,
-                                             unsigned int *pvalue)
+                                             unsigned int *pvalue,
+                                             Error **errp)
 {
-    return xen_host_pci_get_value(d, name, pvalue, 16);
+    return xen_host_pci_get_value(d, name, pvalue, 16, errp);
 }
 
 static inline int xen_host_pci_get_dec_value(XenHostPCIDevice *d,
                                              const char *name,
-                                             unsigned int *pvalue)
+                                             unsigned int *pvalue,
+                                             Error **errp)
 {
-    return xen_host_pci_get_value(d, name, pvalue, 10);
+    return xen_host_pci_get_value(d, name, pvalue, 10, errp);
 }
 
 static bool xen_host_pci_dev_is_virtfn(XenHostPCIDevice *d)
@@ -206,20 +218,21 @@ static bool xen_host_pci_dev_is_virtfn(XenHostPCIDevice *d)
     return !stat(path, &buf);
 }
 
-static int xen_host_pci_config_open(XenHostPCIDevice *d)
+static void xen_host_pci_config_open(XenHostPCIDevice *d, Error **errp)
 {
     char path[PATH_MAX];
     int rc;
 
     rc = xen_host_pci_sysfs_path(d, "config", path, sizeof (path));
     if (rc) {
-        return rc;
+        error_setg_errno(errp, errno, "snprintf err");
+        return;
     }
+
     d->config_fd = open(path, O_RDWR);
     if (d->config_fd < 0) {
-        return -errno;
+        error_setg_errno(errp, errno, "open err");
     }
-    return 0;
 }
 
 static int xen_host_pci_config_read(XenHostPCIDevice *d,
@@ -341,8 +354,9 @@ int xen_host_pci_find_ext_cap_offset(XenHostPCIDevice *d, uint32_t cap)
     return -1;
 }
 
-int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
-                            uint8_t bus, uint8_t dev, uint8_t func)
+void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
+                            uint8_t bus, uint8_t dev, uint8_t func,
+                            Error **errp)
 {
     unsigned int v;
     int rc = 0;
@@ -353,43 +367,48 @@ int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
     d->dev = dev;
     d->func = func;
 
-    rc = xen_host_pci_config_open(d);
-    if (rc) {
+    xen_host_pci_config_open(d, errp);
+    if (*errp) {
         goto error;
     }
-    rc = xen_host_pci_get_resource(d);
-    if (rc) {
+
+    xen_host_pci_get_resource(d, errp);
+    if (*errp) {
         goto error;
     }
-    rc = xen_host_pci_get_hex_value(d, "vendor", &v);
+
+    rc = xen_host_pci_get_hex_value(d, "vendor", &v, errp);
     if (rc) {
         goto error;
     }
     d->vendor_id = v;
-    rc = xen_host_pci_get_hex_value(d, "device", &v);
+
+    rc = xen_host_pci_get_hex_value(d, "device", &v, errp);
     if (rc) {
         goto error;
     }
     d->device_id = v;
-    rc = xen_host_pci_get_dec_value(d, "irq", &v);
+
+    rc = xen_host_pci_get_dec_value(d, "irq", &v, errp);
     if (rc) {
         goto error;
     }
     d->irq = v;
-    rc = xen_host_pci_get_hex_value(d, "class", &v);
+
+    rc = xen_host_pci_get_hex_value(d, "class", &v, errp);
     if (rc) {
         goto error;
     }
     d->class_code = v;
+
     d->is_virtfn = xen_host_pci_dev_is_virtfn(d);
 
-    return 0;
+    return;
 error:
     if (d->config_fd >= 0) {
         close(d->config_fd);
         d->config_fd = -1;
     }
-    return rc;
 }
 
 bool xen_host_pci_device_closed(XenHostPCIDevice *d)
diff --git a/hw/xen/xen-host-pci-device.h b/hw/xen/xen-host-pci-device.h
index 3d44e04..42b9138 100644
--- a/hw/xen/xen-host-pci-device.h
+++ b/hw/xen/xen-host-pci-device.h
@@ -36,8 +36,9 @@ typedef struct XenHostPCIDevice {
     int config_fd;
 } XenHostPCIDevice;
 
-int xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
-                            uint8_t bus, uint8_t dev, uint8_t func);
+void xen_host_pci_device_get(XenHostPCIDevice *d, uint16_t domain,
+                            uint8_t bus, uint8_t dev, uint8_t func,
+                            Error **errp);
 void xen_host_pci_device_put(XenHostPCIDevice *pci_dev);
 bool xen_host_pci_device_closed(XenHostPCIDevice *d);
 
diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
index aa96288..5f4cbb7 100644
--- a/hw/xen/xen_pt.c
+++ b/hw/xen/xen_pt.c
@@ -760,10 +760,10 @@ static void xen_pt_destroy(PCIDevice *d) {
 }
 /* init */
 
-static int xen_pt_initfn(PCIDevice *d)
+static void xen_pt_realize(PCIDevice *d, Error **errp)
 {
     XenPCIPassthroughState *s = XEN_PT_DEVICE(d);
-    int rc = 0;
+    int i, rc = 0;
     uint8_t machine_irq = 0, scratch;
     uint16_t cmd = 0;
     int pirq = XEN_PT_UNASSIGNED_PIRQ;
@@ -774,12 +774,11 @@ static int xen_pt_initfn(PCIDevice *d)
                s->hostaddr.bus, s->hostaddr.slot, s->hostaddr.function,
                s->dev.devfn);
 
-    rc = xen_host_pci_device_get(&s->real_device,
-                                 s->hostaddr.domain, s->hostaddr.bus,
-                                 s->hostaddr.slot, s->hostaddr.function);
-    if (rc) {
-        XEN_PT_ERR(d, "Failed to \"open\" the real pci device. rc: %i\n", rc);
-        return -1;
+    xen_host_pci_device_get(&s->real_device,
+                            s->hostaddr.domain, s->hostaddr.bus,
+                            s->hostaddr.slot, s->hostaddr.function, errp);
+    if (*errp) {
+        return;
     }
 
     s->is_virtfn = s->real_device.is_virtfn;
@@ -799,16 +798,17 @@ static int xen_pt_initfn(PCIDevice *d)
     if ((s->real_device.domain == 0) && (s->real_device.bus == 0) &&
         (s->real_device.dev == 2) && (s->real_device.func == 0)) {
         if (!is_igd_vga_passthrough(&s->real_device)) {
-            XEN_PT_ERR(d, "Need to enable igd-passthru if you're trying"
-                       " to passthrough IGD GFX.\n");
+            error_setg(errp, "Need to enable igd-passthru if you're trying"
+                    " to passthrough IGD GFX.");
             xen_host_pci_device_put(&s->real_device);
-            return -1;
+            return;
         }
 
-        if (xen_pt_setup_vga(s, &s->real_device) < 0) {
-            XEN_PT_ERR(d, "Setup VGA BIOS of passthrough GFX failed!\n");
+        if (xen_pt_setup_vga(s, &s->real_device, errp) < 0) {
+            error_append_hint(errp, "Setup VGA BIOS of passthrough"
+                    " GFX failed!");
             xen_host_pci_device_put(&s->real_device);
-            return -1;
+            return;
         }
 
         /* Register ISA bridge for passthrough GFX. */
@@ -819,29 +819,28 @@ static int xen_pt_initfn(PCIDevice *d)
     xen_pt_register_regions(s, &cmd);
 
     /* reinitialize each config register to be emulated */
-    rc = xen_pt_config_init(s);
-    if (rc) {
-        XEN_PT_ERR(d, "PCI Config space initialisation failed.\n");
+    xen_pt_config_init(s, errp);
+    if (*errp) {
+        error_append_hint(errp, "PCI Config space initialisation failed.");
         goto err_out;
     }
 
     /* Bind interrupt */
     rc = xen_host_pci_get_byte(&s->real_device, PCI_INTERRUPT_PIN, &scratch);
     if (rc) {
-        XEN_PT_ERR(d, "Failed to read PCI_INTERRUPT_PIN! (rc:%d)\n", rc);
+        error_setg_errno(errp, errno, "Failed to read PCI_INTERRUPT_PIN!");
         goto err_out;
     }
     if (!scratch) {
-        XEN_PT_LOG(d, "no pin interrupt\n");
+        error_setg(errp, "no pin interrupt");
         goto out;
     }
 
     machine_irq = s->real_device.irq;
     rc = xc_physdev_map_pirq(xen_xc, xen_domid, machine_irq, &pirq);
-
     if (rc < 0) {
-        XEN_PT_ERR(d, "Mapping machine irq %u to pirq %i failed, (err: %d)\n",
-                   machine_irq, pirq, errno);
+        error_setg_errno(errp, errno, "Mapping machine irq %u to"
+                         " pirq %i failed", machine_irq, pirq);
 
         /* Disable PCI intx assertion (turn on bit10 of devctl) */
         cmd |= PCI_COMMAND_INTX_DISABLE;
@@ -862,8 +861,8 @@ static int xen_pt_initfn(PCIDevice *d)
                                        PCI_SLOT(d->devfn),
                                        e_intx);
         if (rc < 0) {
-            XEN_PT_ERR(d, "Binding of interrupt %i failed! (err: %d)\n",
-                       e_intx, errno);
+            error_setg_errno(errp, errno, "Binding of interrupt %i failed!",
+                             e_intx);
 
             /* Disable PCI intx assertion (turn on bit10 of devctl) */
             cmd |= PCI_COMMAND_INTX_DISABLE;
@@ -871,8 +870,8 @@ static int xen_pt_initfn(PCIDevice *d)
 
             if (xen_pt_mapped_machine_irq[machine_irq] == 0) {
                 if (xc_physdev_unmap_pirq(xen_xc, xen_domid, machine_irq)) {
-                    XEN_PT_ERR(d, "Unmapping of machine interrupt %i failed!"
-                               " (err: %d)\n", machine_irq, errno);
+                    error_setg_errno(errp, errno, "Unmapping of machine"
+                            " interrupt %i failed!", machine_irq);
                 }
             }
             s->machine_irq = 0;
@@ -885,14 +884,14 @@ out:
 
         rc = xen_host_pci_get_word(&s->real_device, PCI_COMMAND, &val);
         if (rc) {
-            XEN_PT_ERR(d, "Failed to read PCI_COMMAND! (rc: %d)\n", rc);
+            error_setg_errno(errp, errno, "Failed to read PCI_COMMAND!");
             goto err_out;
         } else {
             val |= cmd;
             rc = xen_host_pci_set_word(&s->real_device, PCI_COMMAND, val);
             if (rc) {
-                XEN_PT_ERR(d, "Failed to write PCI_COMMAND val=0x%x!(rc: %d)\n",
-                           val, rc);
+                error_setg_errno(errp, errno, "Failed to write PCI_COMMAND"
+                                 " val=0x%x!", val);
                 goto err_out;
             }
         }
@@ -905,12 +904,16 @@ out:
                "Real physical device %02x:%02x.%d registered successfully!\n",
                s->hostaddr.bus, s->hostaddr.slot, s->hostaddr.function);
 
-    return 0;
+    return;
 
 err_out:
+    for (i = 0; i < PCI_ROM_SLOT; i++) {
+        object_unparent(OBJECT(&s->bar[i]));
+    }
+    object_unparent(OBJECT(&s->rom));
+
     xen_pt_destroy(d);
     assert(rc);
-    return rc;
 }
 
 static void xen_pt_unregister_device(PCIDevice *d)
@@ -929,7 +932,7 @@ static void xen_pci_passthrough_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 
-    k->init = xen_pt_initfn;
+    k->realize = xen_pt_realize;
     k->exit = xen_pt_unregister_device;
     k->config_read = xen_pt_pci_read_config;
     k->config_write = xen_pt_pci_write_config;
diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h
index c545280..b4b0c19 100644
--- a/hw/xen/xen_pt.h
+++ b/hw/xen/xen_pt.h
@@ -228,7 +228,7 @@ struct XenPCIPassthroughState {
     bool listener_set;
 };
 
-int xen_pt_config_init(XenPCIPassthroughState *s);
+void xen_pt_config_init(XenPCIPassthroughState *s, Error **errp);
 void xen_pt_config_delete(XenPCIPassthroughState *s);
 XenPTRegGroup *xen_pt_find_reg_grp(XenPCIPassthroughState *s, uint32_t address);
 XenPTReg *xen_pt_find_reg(XenPTRegGroup *reg_grp, uint32_t address);
@@ -328,5 +328,6 @@ static inline bool is_igd_vga_passthrough(XenHostPCIDevice *dev)
 }
 int xen_pt_register_vga_regions(XenHostPCIDevice *dev);
 int xen_pt_unregister_vga_regions(XenHostPCIDevice *dev);
-int xen_pt_setup_vga(XenPCIPassthroughState *s, XenHostPCIDevice *dev);
+int xen_pt_setup_vga(XenPCIPassthroughState *s, XenHostPCIDevice *dev,
+                     Error **errp);
 #endif /* !XEN_PT_H */
diff --git a/hw/xen/xen_pt_config_init.c b/hw/xen/xen_pt_config_init.c
index 3d8686d..dad2032 100644
--- a/hw/xen/xen_pt_config_init.c
+++ b/hw/xen/xen_pt_config_init.c
@@ -1899,8 +1899,9 @@ static uint8_t find_cap_offset(XenPCIPassthroughState *s, uint8_t cap)
     return 0;
 }
 
-static int xen_pt_config_reg_init(XenPCIPassthroughState *s,
-                                  XenPTRegGroup *reg_grp, XenPTRegInfo *reg)
+static void xen_pt_config_reg_init(XenPCIPassthroughState *s,
+                                  XenPTRegGroup *reg_grp, XenPTRegInfo *reg,
+                                  Error **errp)
 {
     XenPTReg *reg_entry;
     uint32_t data = 0;
@@ -1919,12 +1920,14 @@ static int xen_pt_config_reg_init(XenPCIPassthroughState *s,
                        reg_grp->base_offset + reg->offset, &data);
         if (rc < 0) {
             g_free(reg_entry);
-            return rc;
+            error_setg(errp, "Init emulate register fail!");
+            return;
         }
         if (data == XEN_PT_INVALID_REG) {
             /* free unused BAR register entry */
             g_free(reg_entry);
-            return 0;
+            error_setg(errp, "Invalid register value");
+            return;
         }
         /* Sync up the data to dev.config */
         offset = reg_grp->base_offset + reg->offset;
@@ -1942,7 +1945,8 @@ static int xen_pt_config_reg_init(XenPCIPassthroughState *s,
         if (rc) {
             /* Serious issues when we cannot read the host values! */
             g_free(reg_entry);
-            return rc;
+            error_setg(errp, "Cannot read host values!");
+            return;
         }
         /* Set bits in emu_mask are the ones we emulate. The dev.config shall
          * contain the emulated view of the guest - therefore we flip the mask
@@ -1967,10 +1971,10 @@ static int xen_pt_config_reg_init(XenPCIPassthroughState *s,
             val = data;
 
         if (val & ~size_mask) {
-            XEN_PT_ERR(&s->dev,"Offset 0x%04x:0x%04x expands past register size(%d)!\n",
-                       offset, val, reg->size);
+            error_setg(errp, "Offset 0x%04x:0x%04x expands past"
+                    " register size(%d)!", offset, val, reg->size);
             g_free(reg_entry);
-            return -ENXIO;
+            return;
         }
         /* This could be just pci_set_long as we don't modify the bits
          * past reg->size, but in case this routine is run in parallel or the
@@ -1990,11 +1994,9 @@ static int xen_pt_config_reg_init(XenPCIPassthroughState *s,
     }
     /* list add register entry */
     QLIST_INSERT_HEAD(&reg_grp->reg_tbl_list, reg_entry, entries);
-
-    return 0;
 }
 
-int xen_pt_config_init(XenPCIPassthroughState *s)
+void xen_pt_config_init(XenPCIPassthroughState *s, Error **errp)
 {
     int i, rc;
 
@@ -2039,11 +2041,11 @@ int xen_pt_config_init(XenPCIPassthroughState *s)
                                                   reg_grp_offset,
                                                   &reg_grp_entry->size);
             if (rc < 0) {
-                XEN_PT_LOG(&s->dev, "Failed to initialize %d/%ld, type=0x%x, rc:%d\n",
-                           i, ARRAY_SIZE(xen_pt_emu_reg_grps),
+                error_setg(errp, "Failed to initialize %d/%ld, type=0x%x,"
+                           " rc:%d\n", i, ARRAY_SIZE(xen_pt_emu_reg_grps),
                            xen_pt_emu_reg_grps[i].grp_type, rc);
                 xen_pt_config_delete(s);
-                return rc;
+                return;
             }
         }
 
@@ -2054,21 +2056,20 @@ int xen_pt_config_init(XenPCIPassthroughState *s)
                 /* initialize capability register */
                 for (j = 0; regs->size != 0; j++, regs++) {
                     /* initialize capability register */
-                    rc = xen_pt_config_reg_init(s, reg_grp_entry, regs);
-                    if (rc < 0) {
-                        XEN_PT_LOG(&s->dev, "Failed to initialize %d/%ld reg 0x%x in grp_type=0x%x (%d/%ld), rc=%d\n",
-                                   j, ARRAY_SIZE(xen_pt_emu_reg_grps[i].emu_regs),
-                                   regs->offset, xen_pt_emu_reg_grps[i].grp_type,
-                                   i, ARRAY_SIZE(xen_pt_emu_reg_grps), rc);
+                    xen_pt_config_reg_init(s, reg_grp_entry, regs, errp);
+                    if (*errp) {
+                        error_append_hint(errp, "Failed to initialize %d/%ld"
+                                " reg 0x%x in grp_type=0x%x (%d/%ld), rc=%d\n",
+                                j, ARRAY_SIZE(xen_pt_emu_reg_grps[i].emu_regs),
+                                regs->offset, xen_pt_emu_reg_grps[i].grp_type,
+                                i, ARRAY_SIZE(xen_pt_emu_reg_grps), rc);
                         xen_pt_config_delete(s);
-                        return rc;
+                        return;
                     }
                 }
             }
         }
     }
-
-    return 0;
 }
 
 /* delete all emulate register */
diff --git a/hw/xen/xen_pt_graphics.c b/hw/xen/xen_pt_graphics.c
index df6069b..17e7a59 100644
--- a/hw/xen/xen_pt_graphics.c
+++ b/hw/xen/xen_pt_graphics.c
@@ -161,7 +161,8 @@ struct pci_data {
     uint16_t reserved;
 } __attribute__((packed));
 
-int xen_pt_setup_vga(XenPCIPassthroughState *s, XenHostPCIDevice *dev)
+int xen_pt_setup_vga(XenPCIPassthroughState *s, XenHostPCIDevice *dev,
+                     Error **errp)
 {
     unsigned char *bios = NULL;
     struct rom_header *rom;
@@ -172,12 +173,13 @@ int xen_pt_setup_vga(XenPCIPassthroughState *s, XenHostPCIDevice *dev)
     struct pci_data *pd = NULL;
 
     if (!is_igd_vga_passthrough(dev)) {
+        error_setg(errp, "Need to enable igd-passthrough");
         return -1;
     }
 
     bios = get_vgabios(s, &bios_size, dev);
     if (!bios) {
-        XEN_PT_ERR(&s->dev, "VGA: Can't getting VBIOS!\n");
+        error_setg(errp, "VGA: Can't getting VBIOS!");
         return -1;
     }
 
