path: root/backends/msmouse.c
diff options
authorMichael Roth <mdroth@linux.vnet.ibm.com>2013-06-07 15:19:53 -0500
committerAnthony Liguori <aliguori@us.ibm.com>2013-06-10 11:38:37 -0500
commitbd5c51ee6c4f1c79cae5ad2516d711a27b4ea8ec (patch)
tree269a4fb0e0b09eff045ab897e1ef953c184bfd61 /backends/msmouse.c
parentb62cd318daaa3d94c150d87dc2c8466b9463cef5 (diff)
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: 86e94dea5b740dad65446c857f6959eae43e0ba6 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 9f939df955a4152aad69a19a77e0898631bb2c18, 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>
Diffstat (limited to 'backends/msmouse.c')
1 files changed, 1 insertions, 0 deletions
diff --git a/backends/msmouse.c b/backends/msmouse.c
index 0ac05a0d10..c0dbfcdd6b 100644
--- a/backends/msmouse.c
+++ b/backends/msmouse.c
@@ -70,6 +70,7 @@ CharDriverState *qemu_chr_open_msmouse(void)
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");