xemu/backends/msmouse.c
Michael Roth bd5c51ee6c qemu-char: don't issue CHR_EVENT_OPEN in a BH
When CHR_EVENT_OPENED was initially added, it was CHR_EVENT_RESET,
and it was issued as a bottom-half:

86e94dea5b

Which we basically used to print out a greeting/prompt for the
monitor.

AFAICT the only reason this was ever done in a BH was because in
some cases we'd modify the chr_write handler for a new chardev
backend *after* the site where we issued the reset (see:
86e94d:qemu_chr_open_stdio())

At some point this event was renamed to CHR_EVENT_OPENED, and we've
maintained the use of this BH ever since.

However, due to 9f939df955, we schedule
the BH via g_idle_add(), which is causing events to sometimes be
delivered after we've already begun processing data from backends,
leading to:

 known bugs:

  QMP:
    session negotation resets with OPENED event, in some cases this
    is causing new sessions to get sporadically reset

 potential bugs:

  hw/usb/redirect.c:
    can_read handler checks for dev->parser != NULL, which may be
    true if CLOSED BH has not been executed yet. In the past, OPENED
    quiesced outstanding CLOSED events prior to us reading client
    data. If it's delayed, our check may allow reads to occur even
    though we haven't processed the OPENED event yet, and when we
    do finally get the OPENED event, our state may get reset.

  qtest.c:
    can begin session before OPENED event is processed, leading to
    a spurious reset of the system and irq_levels

  gdbstub.c:
    may start a gdb session prior to the machine being paused

To fix these, let's just drop the BH.

Since the initial reasoning for using it still applies to an extent,
work around that by deferring the delivery of CHR_EVENT_OPENED until
after the chardevs have been fully initialized, toward the end of
qmp_chardev_add() (or some cases, qemu_chr_new_from_opts()). This
defers delivery long enough that we can be assured a CharDriverState
is fully initialized before CHR_EVENT_OPENED is sent.

Also, rather than requiring each chardev to do an explicit open, do it
automatically, and allow the small few who don't desire such behavior to
suppress the OPENED-on-init behavior by setting a 'explicit_be_open'
flag.

We additionally add missing OPENED events for stdio backends on w32,
which were previously not being issued, causing us to not recieve the
banner and initial prompts for qmp/hmp.

Reported-by: Stefan Priebe <s.priebe@profihost.ag>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Message-id: 1370636393-21044-1-git-send-email-mdroth@linux.vnet.ibm.com
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-06-10 11:38:37 -05:00

86 lines
2.8 KiB
C

/*
* QEMU Microsoft serial mouse emulation
*
* Copyright (c) 2008 Lubomir Rintel
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <stdlib.h>
#include "qemu-common.h"
#include "sysemu/char.h"
#include "ui/console.h"
#define MSMOUSE_LO6(n) ((n) & 0x3f)
#define MSMOUSE_HI2(n) (((n) & 0xc0) >> 6)
static void msmouse_event(void *opaque,
int dx, int dy, int dz, int buttons_state)
{
CharDriverState *chr = (CharDriverState *)opaque;
unsigned char bytes[4] = { 0x40, 0x00, 0x00, 0x00 };
/* Movement deltas */
bytes[0] |= (MSMOUSE_HI2(dy) << 2) | MSMOUSE_HI2(dx);
bytes[1] |= MSMOUSE_LO6(dx);
bytes[2] |= MSMOUSE_LO6(dy);
/* Buttons */
bytes[0] |= (buttons_state & 0x01 ? 0x20 : 0x00);
bytes[0] |= (buttons_state & 0x02 ? 0x10 : 0x00);
bytes[3] |= (buttons_state & 0x04 ? 0x20 : 0x00);
/* We always send the packet of, so that we do not have to keep track
of previous state of the middle button. This can potentially confuse
some very old drivers for two button mice though. */
qemu_chr_be_write(chr, bytes, 4);
}
static int msmouse_chr_write (struct CharDriverState *s, const uint8_t *buf, int len)
{
/* Ignore writes to mouse port */
return len;
}
static void msmouse_chr_close (struct CharDriverState *chr)
{
g_free (chr);
}
CharDriverState *qemu_chr_open_msmouse(void)
{
CharDriverState *chr;
chr = g_malloc0(sizeof(CharDriverState));
chr->chr_write = msmouse_chr_write;
chr->chr_close = msmouse_chr_close;
chr->explicit_be_open = true;
qemu_add_mouse_event_handler(msmouse_event, chr, 0, "QEMU Microsoft Mouse");
return chr;
}
static void register_types(void)
{
register_char_driver_qapi("msmouse", CHARDEV_BACKEND_KIND_MSMOUSE, NULL);
}
type_init(register_types);