usb: use iovecs in USBPacket

Zap data pointer from USBPacket, add a QEMUIOVector instead.
Add a bunch of helper functions to manage USBPacket data.
Switch over users to the new interface.

Note that USBPacket->len was used for two purposes:  First to
pass in the buffer size and second to return the number of
transfered bytes or the status code on async transfers.  There
is a new result variable for the latter.  A new status code
was added to catch uninitialized result.

Nobody creates iovecs with more than one element (yet).
Some users are (temporarely) limited to iovecs with a single
element to keep the patch size as small as possible.

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

1 files changed, 4 insertions, 4 deletions

diff --git a/hw/milkymist-softusb.c b/hw/milkymist-softusb.c
index abf7b59acd..75c85aeb6f 100644
--- a/hw/milkymist-softusb.c
+++ b/hw/milkymist-softusb.c
@@ -234,11 +234,11 @@ static void softusb_usbdev_datain(void *opaque)
 
     USBPacket p;
 
-    p.pid = USB_TOKEN_IN;
-    p.devep = 1;
-    p.data = s->kbd_usb_buffer;
-    p.len = sizeof(s->kbd_usb_buffer);
+    usb_packet_init(&p);
+    usb_packet_setup(&p, USB_TOKEN_IN, 0, 1);
+    usb_packet_addbuf(&p, s->kbd_usb_buffer, sizeof(s->kbd_usb_buffer));
     s->usbdev->info->handle_data(s->usbdev, &p);
+    usb_packet_cleanup(&p);
 
     softusb_kbd_changed(s);
 }