[08/24] usb descriptors: add settable strings.

diff --git a/hw/usb-bus.c b/hw/usb-bus.c
index b692503..15a42ff 100644
--- a/hw/usb-bus.c
+++ b/hw/usb-bus.c
@@ -46,6 +46,7 @@  static int usb_qdev_init(DeviceState *qdev, DeviceInfo *base)
     pstrcpy(dev->product_desc, sizeof(dev->product_desc), info->product_desc);
     dev->info = info;
     dev->auto_attach = 1;
+    QLIST_INIT(&dev->strings);
     rc = dev->info->init(dev);
     if (rc == 0 && dev->auto_attach)
         usb_device_attach(dev);
diff --git a/hw/usb-desc.c b/hw/usb-desc.c
index 559ced7..69ab207 100644
--- a/hw/usb-desc.c
+++ b/hw/usb-desc.c
@@ -151,9 +151,42 @@  int usb_desc_other(const USBDescOther *desc, uint8_t *dest, size_t len)
     return bLength;
 }
 
-int usb_desc_string(const char* const *str, int index, uint8_t *dest, size_t len)
+/* ------------------------------------------------------------------ */
+
+void usb_desc_set_string(USBDevice *dev, uint8_t index, const char *str)
+{
+    USBDescString *s;
+
+    QLIST_FOREACH(s, &dev->strings, next) {
+        if (s->index == index) {
+            break;
+        }
+    }
+    if (s == NULL) {
+        s = qemu_mallocz(sizeof(*s));
+        s->index = index;
+        QLIST_INSERT_HEAD(&dev->strings, s, next);
+    }
+    qemu_free(s->str);
+    s->str = qemu_strdup(str);
+}
+
+const char *usb_desc_get_string(USBDevice *dev, uint8_t index)
+{
+    USBDescString *s;
+
+    QLIST_FOREACH(s, &dev->strings, next) {
+        if (s->index == index) {
+            return s->str;
+        }
+    }
+    return NULL;
+}
+
+int usb_desc_string(USBDevice *dev, int index, uint8_t *dest, size_t len)
 {
     uint8_t bLength, pos, i;
+    const char *str;
 
     if (len < 4) {
         return -1;
@@ -168,22 +201,25 @@  int usb_desc_string(const char* const *str, int index, uint8_t *dest, size_t len
         return 4;
     }
 
-    if (str[index] == NULL) {
-        return 0;
+    str = usb_desc_get_string(dev, index);
+    if (str == NULL) {
+        str = dev->info->usb_desc->str[index];
+        if (str == NULL) {
+            return 0;
+        }
     }
-    bLength = strlen(str[index]) * 2 + 2;
+
+    bLength = strlen(str) * 2 + 2;
     dest[0] = bLength;
     dest[1] = USB_DT_STRING;
     i = 0; pos = 2;
     while (pos+1 < bLength && pos+1 < len) {
-        dest[pos++] = str[index][i++];
+        dest[pos++] = str[i++];
         dest[pos++] = 0;
     }
     return pos;
 }
 
-/* ------------------------------------------------------------------ */
-
 int usb_desc_get_descriptor(USBDevice *dev, int value, uint8_t *dest, size_t len)
 {
     const USBDesc *desc = dev->info->usb_desc;
@@ -204,7 +240,7 @@  int usb_desc_get_descriptor(USBDevice *dev, int value, uint8_t *dest, size_t len
         trace_usb_desc_config(dev->addr, index, len, ret);
         break;
     case USB_DT_STRING:
-        ret = usb_desc_string(desc->str, index, buf, sizeof(buf));
+        ret = usb_desc_string(dev, index, buf, sizeof(buf));
         trace_usb_desc_string(dev->addr, index, len, ret);
         break;
     default:
diff --git a/hw/usb-desc.h b/hw/usb-desc.h
index d80efdb..20fc400 100644
--- a/hw/usb-desc.h
+++ b/hw/usb-desc.h
@@ -76,9 +76,11 @@  int usb_desc_config(const USBDescConfig *conf, uint8_t *dest, size_t len);
 int usb_desc_iface(const USBDescIface *iface, uint8_t *dest, size_t len);
 int usb_desc_endpoint(const USBDescEndpoint *ep, uint8_t *dest, size_t len);
 int usb_desc_other(const USBDescOther *desc, uint8_t *dest, size_t len);
-int usb_desc_string(const char* const *str, int index, uint8_t *dest, size_t len);
 
 /* control message emulation helpers */
+void usb_desc_set_string(USBDevice *dev, uint8_t index, const char *str);
+const char *usb_desc_get_string(USBDevice *dev, uint8_t index);
+int usb_desc_string(USBDevice *dev, int index, uint8_t *dest, size_t len);
 int usb_desc_get_descriptor(USBDevice *dev, int value, uint8_t *dest, size_t len);
 int usb_desc_handle_control(USBDevice *dev, int request, int value,
                             int index, int length, uint8_t *data);
diff --git a/hw/usb.h b/hw/usb.h
index 3aeb975..760550d 100644
--- a/hw/usb.h
+++ b/hw/usb.h
@@ -135,6 +135,13 @@  typedef struct USBDescConfig USBDescConfig;
 typedef struct USBDescIface USBDescIface;
 typedef struct USBDescEndpoint USBDescEndpoint;
 typedef struct USBDescOther USBDescOther;
+typedef struct USBDescString USBDescString;
+
+struct USBDescString {
+    uint8_t index;
+    char *str;
+    QLIST_ENTRY(USBDescString) next;
+};
 
 /* definition of a USB device */
 struct USBDevice {
@@ -155,6 +162,8 @@  struct USBDevice {
     int setup_state;
     int setup_len;
     int setup_index;
+
+    QLIST_HEAD(, USBDescString) strings;
 };
 
 struct USBDeviceInfo {