usb-redir: Allow to attach USB 2.0 devices to 1.1 host controller

This follows the logic of host-linux: If a 2.0 device has no ISO
endpoint and no interrupt endpoint with a packet size > 64, we can
attach it also to an 1.1 host controller. In case the redir server does
not report endpoint sizes, play safe and remove the 1.1 compatibility as
well. Moreover, if we detect a conflicting change in the configuration
after the device was already attached, it will be disconnected
immediately.

HdG: Several small cleanups and fixes

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/usb/redirect.c

@@ -106,6 +106,7 @@ struct USBRedirDevice {
     struct usb_redir_interface_info_header interface_info;
     struct usbredirfilter_rule *filter_rules;
     int filter_rules_count;
+    int compatible_speedmask;
 };
 
 static void usbredir_hello(void *priv, struct usb_redir_hello_header *h);
@@ -962,6 +963,7 @@ static void usbredir_do_attach(void *opaque)
     }
 
     if (usb_device_attach(&dev->dev) != 0) {
+        WARNING("rejecting device due to speed mismatch\n");
         usbredir_reject_device(dev);
     }
 }
@@ -1068,6 +1070,9 @@ static int usbredir_initfn(USBDevice *udev)
     /* We'll do the attach once we receive the speed from the usb-host */
     udev->auto_attach = 0;
 
+    /* Will be cleared during setup when we find conflicts */
+    dev->compatible_speedmask = USB_SPEED_MASK_FULL;
+
     /* Let the backend know we are ready */
     qemu_chr_fe_open(dev->cs);
     qemu_chr_add_handlers(dev->cs, usbredir_chardev_can_read,
@@ -1208,6 +1213,7 @@ static void usbredir_device_connect(void *priv,
     case usb_redir_speed_low:
         speed = "low speed";
         dev->dev.speed = USB_SPEED_LOW;
+        dev->compatible_speedmask &= ~USB_SPEED_MASK_FULL;
         break;
     case usb_redir_speed_full:
         speed = "full speed";
@@ -1241,7 +1247,7 @@ static void usbredir_device_connect(void *priv,
              device_connect->device_class);
     }
 
-    dev->dev.speedmask = (1 << dev->dev.speed);
+    dev->dev.speedmask = (1 << dev->dev.speed) | dev->compatible_speedmask;
     dev->device_info = *device_connect;
 
     if (usbredir_check_filter(dev)) {
@@ -1281,6 +1287,7 @@ static void usbredir_device_disconnect(void *priv)
     dev->interface_info.interface_count = NO_INTERFACE_INFO;
     dev->dev.addr = 0;
     dev->dev.speed = 0;
+    dev->compatible_speedmask = USB_SPEED_MASK_FULL;
 }
 
 static void usbredir_interface_info(void *priv,
@@ -1302,6 +1309,12 @@ static void usbredir_interface_info(void *priv,
     }
 }
 
+static void usbredir_mark_speed_incompatible(USBRedirDevice *dev, int speed)
+{
+    dev->compatible_speedmask &= ~(1 << speed);
+    dev->dev.speedmask = (1 << dev->dev.speed) | dev->compatible_speedmask;
+}
+
 static void usbredir_set_pipeline(USBRedirDevice *dev, struct USBEndpoint *uep)
 {
     if (uep->type != USB_ENDPOINT_XFER_BULK) {
@@ -1350,7 +1363,14 @@ static void usbredir_ep_info(void *priv,
         case usb_redir_type_invalid:
             break;
         case usb_redir_type_iso:
+            usbredir_mark_speed_incompatible(dev, USB_SPEED_FULL);
+            /* Fall through */
         case usb_redir_type_interrupt:
+            if (!usbredirparser_peer_has_cap(dev->parser,
+                                     usb_redir_cap_ep_info_max_packet_size) ||
+                    ep_info->max_packet_size[i] > 64) {
+                usbredir_mark_speed_incompatible(dev, USB_SPEED_FULL);
+            }
             if (dev->endpoint[i].interval == 0) {
                 ERROR("Received 0 interval for isoc or irq endpoint\n");
                 usbredir_reject_device(dev);
@@ -1368,6 +1388,14 @@ static void usbredir_ep_info(void *priv,
             return;
         }
     }
+    /* The new ep info may have caused a speed incompatibility, recheck */
+    if (dev->dev.attached &&
+            !(dev->dev.port->speedmask & dev->dev.speedmask)) {
+        ERROR("Device no longer matches speed after endpoint info change, "
+              "disconnecting!\n");
+        usbredir_reject_device(dev);
+        return;
+    }
     usbredir_setup_usb_eps(dev);
 }