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);
--
1.7.12.1