From b89a0cc1ec9dbe30cbe002f12d487a52950da166 Mon Sep 17 00:00:00 2001

From: Hans de Goede <hdegoede@redhat.com>

Date: Thu, 23 Aug 2012 16:37:19 +0200

Subject: [PATCH] usb-redir: Don't delay handling of open events to a bottom

 half

There is no need for this, and doing so means that a backend trying to

write immediately after an open event will see qemu_chr_be_can_write

returning 0, which not all backends handle well as there is no wakeup

mechanism to detect when the frontend does become writable.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

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

(cherry picked from commit ed9873bfbf145c084d039baab08c63b9d67e7bd3)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

---

 hw/usb/redirect.c | 100 +++++++++++++++++++++++++++++-------------------------

 1 file changed, 53 insertions(+), 47 deletions(-)

diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c

index 7f3719b..5cc3334 100644

--- a/hw/usb/redirect.c

+++ b/hw/usb/redirect.c

@@ -79,8 +79,8 @@ struct USBRedirDevice {

     /* Data passed from chardev the fd_read cb to the usbredirparser read cb */

     const uint8_t *read_buf;

     int read_buf_size;

-    /* For async handling of open/close */

-    QEMUBH *open_close_bh;

+    /* For async handling of close */

+    QEMUBH *chardev_close_bh;

     /* To delay the usb attach in case of quick chardev close + open */

     QEMUTimer *attach_timer;

     int64_t next_attach_time;

@@ -784,18 +784,11 @@ static int usbredir_handle_control(USBDevice *udev, USBPacket *p,

  * from within the USBDevice data / control packet callbacks and doing a

  * usb_detach from within these callbacks is not a good idea.

  *

- * So we use a bh handler to take care of close events. We also handle

- * open events from this callback to make sure that a close directly followed

- * by an open gets handled in the right order.

+ * So we use a bh handler to take care of close events.

  */

-static void usbredir_open_close_bh(void *opaque)

+static void usbredir_chardev_close_bh(void *opaque)

 {

     USBRedirDevice *dev = opaque;

-    uint32_t caps[USB_REDIR_CAPS_SIZE] = { 0, };

-    char version[32];

-

-    strcpy(version, "qemu usb-redir guest ");

-    pstrcat(version, sizeof(version), qemu_get_version());

     usbredir_device_disconnect(dev);

@@ -803,36 +796,47 @@ static void usbredir_open_close_bh(void *opaque)

         usbredirparser_destroy(dev->parser);

         dev->parser = NULL;

     }

+}

-    if (dev->cs->opened) {

-        dev->parser = qemu_oom_check(usbredirparser_create());

-        dev->parser->priv = dev;

-        dev->parser->log_func = usbredir_log;

-        dev->parser->read_func = usbredir_read;

-        dev->parser->write_func = usbredir_write;

-        dev->parser->hello_func = usbredir_hello;

-        dev->parser->device_connect_func = usbredir_device_connect;

-        dev->parser->device_disconnect_func = usbredir_device_disconnect;

-        dev->parser->interface_info_func = usbredir_interface_info;

-        dev->parser->ep_info_func = usbredir_ep_info;

-        dev->parser->configuration_status_func = usbredir_configuration_status;

-        dev->parser->alt_setting_status_func = usbredir_alt_setting_status;

-        dev->parser->iso_stream_status_func = usbredir_iso_stream_status;

-        dev->parser->interrupt_receiving_status_func =

-            usbredir_interrupt_receiving_status;

-        dev->parser->bulk_streams_status_func = usbredir_bulk_streams_status;

-        dev->parser->control_packet_func = usbredir_control_packet;

-        dev->parser->bulk_packet_func = usbredir_bulk_packet;

-        dev->parser->iso_packet_func = usbredir_iso_packet;

-        dev->parser->interrupt_packet_func = usbredir_interrupt_packet;

-        dev->read_buf = NULL;

-        dev->read_buf_size = 0;

+static void usbredir_chardev_open(USBRedirDevice *dev)

+{

+    uint32_t caps[USB_REDIR_CAPS_SIZE] = { 0, };

+    char version[32];

-        usbredirparser_caps_set_cap(caps, usb_redir_cap_connect_device_version);

-        usbredirparser_caps_set_cap(caps, usb_redir_cap_filter);

-        usbredirparser_init(dev->parser, version, caps, USB_REDIR_CAPS_SIZE, 0);

-        usbredirparser_do_write(dev->parser);

-    }

+    /* Make sure any pending closes are handled (no-op if none pending) */

+    usbredir_chardev_close_bh(dev);

+    qemu_bh_cancel(dev->chardev_close_bh);

+

+    strcpy(version, "qemu usb-redir guest ");

+    pstrcat(version, sizeof(version), qemu_get_version());

+

+    dev->parser = qemu_oom_check(usbredirparser_create());

+    dev->parser->priv = dev;

+    dev->parser->log_func = usbredir_log;

+    dev->parser->read_func = usbredir_read;

+    dev->parser->write_func = usbredir_write;

+    dev->parser->hello_func = usbredir_hello;

+    dev->parser->device_connect_func = usbredir_device_connect;

+    dev->parser->device_disconnect_func = usbredir_device_disconnect;

+    dev->parser->interface_info_func = usbredir_interface_info;

+    dev->parser->ep_info_func = usbredir_ep_info;

+    dev->parser->configuration_status_func = usbredir_configuration_status;

+    dev->parser->alt_setting_status_func = usbredir_alt_setting_status;

+    dev->parser->iso_stream_status_func = usbredir_iso_stream_status;

+    dev->parser->interrupt_receiving_status_func =

+        usbredir_interrupt_receiving_status;

+    dev->parser->bulk_streams_status_func = usbredir_bulk_streams_status;

+    dev->parser->control_packet_func = usbredir_control_packet;

+    dev->parser->bulk_packet_func = usbredir_bulk_packet;

+    dev->parser->iso_packet_func = usbredir_iso_packet;

+    dev->parser->interrupt_packet_func = usbredir_interrupt_packet;

+    dev->read_buf = NULL;

+    dev->read_buf_size = 0;

+

+    usbredirparser_caps_set_cap(caps, usb_redir_cap_connect_device_version);

+    usbredirparser_caps_set_cap(caps, usb_redir_cap_filter);

+    usbredirparser_init(dev->parser, version, caps, USB_REDIR_CAPS_SIZE, 0);

+    usbredirparser_do_write(dev->parser);

 }

 static void usbredir_do_attach(void *opaque)

@@ -856,13 +860,13 @@ static int usbredir_chardev_can_read(void *opaque)

 {

     USBRedirDevice *dev = opaque;

-    if (dev->parser) {

-        /* usbredir_parser_do_read will consume *all* data we give it */

-        return 1024 * 1024;

-    } else {

-        /* usbredir_open_close_bh hasn't handled the open event yet */

+    if (!dev->parser) {

+        WARNING("chardev_can_read called on non open chardev!\n");

         return 0;

     }

+

+    /* usbredir_parser_do_read will consume *all* data we give it */

+    return 1024 * 1024;

 }

 static void usbredir_chardev_read(void *opaque, const uint8_t *buf, int size)

@@ -886,8 +890,10 @@ static void usbredir_chardev_event(void *opaque, int event)

     switch (event) {

     case CHR_EVENT_OPENED:

+        usbredir_chardev_open(dev);

+        break;

     case CHR_EVENT_CLOSED:

-        qemu_bh_schedule(dev->open_close_bh);

+        qemu_bh_schedule(dev->chardev_close_bh);

         break;

     }

 }

@@ -917,7 +923,7 @@ static int usbredir_initfn(USBDevice *udev)

         }

     }

-    dev->open_close_bh = qemu_bh_new(usbredir_open_close_bh, dev);

+    dev->chardev_close_bh = qemu_bh_new(usbredir_chardev_close_bh, dev);

     dev->attach_timer = qemu_new_timer_ms(vm_clock, usbredir_do_attach, dev);

     QTAILQ_INIT(&dev->asyncq);

@@ -957,7 +963,7 @@ static void usbredir_handle_destroy(USBDevice *udev)

     qemu_chr_fe_close(dev->cs);

     qemu_chr_delete(dev->cs);

     /* Note must be done after qemu_chr_close, as that causes a close event */

-    qemu_bh_delete(dev->open_close_bh);

+    qemu_bh_delete(dev->chardev_close_bh);

     qemu_del_timer(dev->attach_timer);

     qemu_free_timer(dev->attach_timer);