usb: add support for microsoft os descriptors

This patch adds support for special usb descriptors used by microsoft
windows.  They allow more fine-grained control over driver binding and
adding entries to the registry for configuration.

As this is a guest-visible change the "msos-desc" compat property
has been added to turn this off for 1.7 + older

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 33 insertions, 4 deletions

diff --git a/hw/usb/desc.c b/hw/usb/desc.c
index f18a043..f133ddb 100644
--- a/hw/usb/desc.c
+++ b/hw/usb/desc.c
@@ -7,7 +7,7 @@
 /* ------------------------------------------------------------------ */
 
 int usb_desc_device(const USBDescID *id, const USBDescDevice *dev,
-                    uint8_t *dest, size_t len)
+                    bool msos, uint8_t *dest, size_t len)
 {
     uint8_t bLength = 0x12;
     USBDescriptor *d = (void *)dest;
@@ -19,8 +19,18 @@ int usb_desc_device(const USBDescID *id, const USBDescDevice *dev,
     d->bLength                     = bLength;
     d->bDescriptorType             = USB_DT_DEVICE;
 
-    d->u.device.bcdUSB_lo          = usb_lo(dev->bcdUSB);
-    d->u.device.bcdUSB_hi          = usb_hi(dev->bcdUSB);
+    if (msos && dev->bcdUSB < 0x0200) {
+        /*
+         * Version 2.0+ required for microsoft os descriptors to work.
+         * Done this way so msos-desc compat property will handle both
+         * the version and the new descriptors being present.
+         */
+        d->u.device.bcdUSB_lo          = usb_lo(0x0200);
+        d->u.device.bcdUSB_hi          = usb_hi(0x0200);
+    } else {
+        d->u.device.bcdUSB_lo          = usb_lo(dev->bcdUSB);
+        d->u.device.bcdUSB_hi          = usb_hi(dev->bcdUSB);
+    }
     d->u.device.bDeviceClass       = dev->bDeviceClass;
     d->u.device.bDeviceSubClass    = dev->bDeviceSubClass;
     d->u.device.bDeviceProtocol    = dev->bDeviceProtocol;
@@ -499,6 +509,10 @@ void usb_desc_init(USBDevice *dev)
     if (desc->super) {
         dev->speedmask |= USB_SPEED_MASK_SUPER;
     }
+    if (desc->msos && (dev->flags & (1 << USB_DEV_FLAG_MSOS_DESC_ENABLE))) {
+        dev->flags |= (1 << USB_DEV_FLAG_MSOS_DESC_IN_USE);
+        usb_desc_set_string(dev, 0xee, "MSFT100Q");
+    }
     usb_desc_setdefaults(dev);
 }
 
@@ -626,6 +640,7 @@ int usb_desc_string(USBDevice *dev, int index, uint8_t *dest, size_t len)
 int usb_desc_get_descriptor(USBDevice *dev, USBPacket *p,
                             int value, uint8_t *dest, size_t len)
 {
+    bool msos = (dev->flags & (1 << USB_DEV_FLAG_MSOS_DESC_IN_USE));
     const USBDesc *desc = usb_device_get_usb_desc(dev);
     const USBDescDevice *other_dev;
     uint8_t buf[256];
@@ -646,7 +661,7 @@ int usb_desc_get_descriptor(USBDevice *dev, USBPacket *p,
 
     switch(type) {
     case USB_DT_DEVICE:
-        ret = usb_desc_device(&desc->id, dev->device, buf, sizeof(buf));
+        ret = usb_desc_device(&desc->id, dev->device, msos, buf, sizeof(buf));
         trace_usb_desc_device(dev->addr, len, ret);
         break;
     case USB_DT_CONFIG:
@@ -703,6 +718,7 @@ int usb_desc_get_descriptor(USBDevice *dev, USBPacket *p,
 int usb_desc_handle_control(USBDevice *dev, USBPacket *p,
         int request, int value, int index, int length, uint8_t *data)
 {
+    bool msos = (dev->flags & (1 << USB_DEV_FLAG_MSOS_DESC_IN_USE));
     const USBDesc *desc = usb_device_get_usb_desc(dev);
     int ret = -1;
 
@@ -782,6 +798,19 @@ int usb_desc_handle_control(USBDevice *dev, USBPacket *p,
         trace_usb_set_interface(dev->addr, index, value, ret);
         break;
 
+    case VendorDeviceRequest | 'Q':
+        if (msos) {
+            ret = usb_desc_msos(desc, p, index, data, length);
+            trace_usb_desc_msos(dev->addr, index, length, ret);
+        }
+        break;
+    case VendorInterfaceRequest | 'Q':
+        if (msos) {
+            ret = usb_desc_msos(desc, p, index, data, length);
+            trace_usb_desc_msos(dev->addr, index, length, ret);
+        }
+        break;
+
     }
     return ret;
 }