[Qemu-devel] [PATCH v2] usb-redir: Allow to attach USB 2.0 devices to 1.1 host controller

[Jan Kiszka <jan.kiszka@web.de>]

From: Jan Kiszka <jan.kiszka@siemens.com>

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.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

Changes in v2:
 - fix incompatibility marking via introduction of compatible_speedmask
 - disconnect device if incompatibility is detected when already
   attached

 hw/usb/redirect.c |   24 +++++++++++++++++++++++-
 1 files changed, 23 insertions(+), 1 deletions(-)

diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index b10241a..2099ea4 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -105,6 +105,7 @@ 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);
@@ -1037,6 +1038,9 @@ 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,
@@ -1177,10 +1181,12 @@ static void usbredir_device_connect(void *priv,
     case usb_redir_speed_low:
         speed = "low speed";
         dev->dev.speed = USB_SPEED_LOW;
+        dev->dev.speedmask = 0;
         break;
     case usb_redir_speed_full:
         speed = "full speed";
         dev->dev.speed = USB_SPEED_FULL;
+        dev->dev.speedmask = 0;
         break;
     case usb_redir_speed_high:
         speed = "high speed";
@@ -1189,6 +1195,7 @@ static void usbredir_device_connect(void *priv,
     case usb_redir_speed_super:
         speed = "super speed";
         dev->dev.speed = USB_SPEED_SUPER;
+        dev->dev.speedmask = 0;
         break;
     default:
         speed = "unknown speed";
@@ -1210,7 +1217,7 @@ 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)) {
@@ -1271,6 +1278,14 @@ static void usbredir_interface_info(void *priv,
     }
 }
 
+static void usbredir_mark_fullspeed_incompatible(USBRedirDevice *dev)
+{
+    dev->compatible_speedmask &= ~USB_SPEED_MASK_FULL;
+    if (dev->dev.attached && dev->dev.port->dev->speed == USB_SPEED_FULL) {
+        usbredir_device_disconnect(dev);
+    }
+}
+
 static void usbredir_ep_info(void *priv,
     struct usb_redir_ep_info_header *ep_info)
 {
@@ -1286,7 +1301,14 @@ static void usbredir_ep_info(void *priv,
         case usb_redir_type_invalid:
             break;
         case usb_redir_type_iso:
+            usbredir_mark_fullspeed_incompatible(dev);
+            /* 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_fullspeed_incompatible(dev);
+            }
             if (dev->endpoint[i].interval == 0) {
                 ERROR("Received 0 interval for isoc or irq endpoint\n");
                 usbredir_device_disconnect(dev);
-- 
1.7.3.4