Commit Graph

289 Commits

Author SHA1 Message Date
Markus Armbruster
3a1da42eb3 qapi: Rename ChardevBackend member "memory" to "ringbuf"
Commit 1da48c6 called the new member "memory" after commit 3949e59
standardized "ringbuf".  Rename for consistency.

However, member name "memory" is visible in QMP since 1.5.  It's
undocumented just like the driver name.  Keep it working anyway.

Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1374849874-25531-4-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-29 10:37:12 -05:00
Markus Armbruster
c11ed9666d qemu-char: Register ring buffer driver with correct name "ringbuf"
The driver is new in 1.4, with the documented name "ringbuf".
However, it's actual name is the completely undocumented "memory".
Screwed up in commit 3949e59.  Fix code to match documentation.

Keep the undocumented name working as an alias for compatibility.

Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1374849874-25531-3-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-29 10:37:11 -05:00
Markus Armbruster
4f57378fe6 Revert "chardev: Make the name of memory device consistent"
This reverts commit 6a85e60cb9.

Commit 51767e7 "qemu-char: Add new char backend CirMemCharDriver"
introduced a memory ring buffer character device driver named
"memory".  Commit 3949e59 "qemu-char: Saner naming of memchar stuff &
doc fixes" changed the driver name to "ringbuf", along with a whole
bunch of other names, with the following rationale:

    Naming is a mess.  The code calls the device driver
    CirMemCharDriver, the public API calls it "memory", "memchardev",
    or "memchar", and the special commands are named like
    "memchar-FOO".  "memory" is a particularly unfortunate choice,
    because there's another character device driver called
    MemoryDriver.  Moreover, the device's distinctive property is that
    it's a ring buffer, not that's in memory.

This is what we released in 1.4.0.

Unfortunately, the rename missed a critical instance of "memory": the
actual driver name.  Thus, the new device could be used only by an
entirely undocumented name.  The documented name did not work.
Bummer.

Commit 6a85e60 fixes this by changing the documentation to match the
code.  It also changes some, but not all related occurences of
"ringbuf" to "memory".  Left alone are identifiers in C code, HMP and
QMP commands.  The latter are external interface, so they can't be
changed.

The result is an inconsistent mess.  Moreover, "memory" is a rotten
name.  The device's distinctive property is that it's a ring buffer,
not that's in memory.  User's don't care whether it's in RAM, flash,
or carved into chocolate tablets by Oompa Loompas.

Revert the commit.  Next commit will fix just the bug.

Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1374849874-25531-2-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-29 10:37:11 -05:00
Laszlo Ersek
ac8c26f633 char: io_channel_send: don't lose written bytes
The g_io_channel_write_chars() documentation states,

  bytes_written: The number of bytes written. This can be nonzero even if
                 the return value is not G_IO_STATUS_NORMAL. [...]

io_channel_send() could lose such bytes before.

Furthermore, the (status == G_IO_STATUS_EOF) condition used to evaluate to
constant false whenever it was reached. When that condition actually held,
it always led to -1 / EINVAL. This patch (almost) distinguishes
G_IO_STATUS_EOF only when no bytes have been written, and then treats it
as an error.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1373998781-29561-2-git-send-email-lersek@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-18 11:22:56 -05:00
Markus Armbruster
0f95305117 qemu-char: Fix ringbuf option size
Any attempt to use it trips an "opt->desc->type == QEMU_OPT_NUMBER"
assertion.  Broken in commit 1da48c65.

Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-07-10 13:39:37 -04:00
Paolo Bonzini
02c4bdf1d2 trap signals for "-serial mon:stdio"
With mon:stdio you can exit the VM by switching to the monitor and
sending the "quit" command.  It is then useful to pass Ctrl-C to the
VM instead of exiting.

This in turn lets us stop tying the default signal handling behavior
to -nographic, removing gratuitous differences between "-display none"
and "-nographic".

This patch changes behavior for "-display none -serial mon:stdio", as
expected, but not for "-display none -serial stdio".

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1372868986-25988-1-git-send-email-mjt@msgid.tls.msk.ru
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-07-09 13:14:06 -05:00
Anthony Liguori
ffeec223b5 Merge remote-tracking branch 'mjt/trivial-patches' into staging
# By Gerd Hoffmann (13) and Michael Tokarev (1)
# Via Michael Tokarev
* mjt/trivial-patches:
  doc: we use seabios, not bochs bios
  qemu-socket: don't leak opts on error
  qemu-char: report udp backend errors
  qemu-char: add -chardev mux support
  qemu-char: minor mux chardev fixes
  qemu-char: use ChardevBackendKind in CharDriver
  qemu-char: don't leak opts on error
  qemu-char: fix documentation for telnet+wait socket flags
  qemu-char: print notification to stderr
  qemu-char: use more specific error_setg_* variants
  qemu-char: check optional fields using has_*
  qemu-socket: catch monitor_get_fd failures
  qemu-socket: drop pointless allocation
  qemu-socket: zero-initialize SocketAddress

Message-id: 1372443465-22384-1-git-send-email-mjt@msgid.tls.msk.ru
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-06-28 15:48:35 -05:00
Markus Armbruster
2ea3e2c1e8 qemu-char: Fix ID reuse after chardev-remove for qapi-based init
Commit 2c5f488 introduced qapi-based character device initialization
as a new code path in qemu_chr_new_from_opts().  Unfortunately, it
failed to store parameter opts in the new chardev.  Therefore,
qemu_chr_delete() doesn't delete it.  Even though the device is gone,
its options linger, and any attempt to create another one with the
same ID fails.

Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1372339512-28149-1-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-06-28 14:04:00 -05:00
Gerd Hoffmann
58a3714c52 qemu-char: report udp backend errors
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-28 22:10:34 +04:00
Gerd Hoffmann
bb6fb7c085 qemu-char: add -chardev mux support
Allow to explicitly create mux chardevs on the command line,
like you can using QMP.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-28 22:10:34 +04:00
Gerd Hoffmann
dc2c4eca89 qemu-char: minor mux chardev fixes
mux failure path has a memory leak.  creating a mux chardev can't
fail though, so just assert() that instead of fixing an error path
which never ever runs anyway ...

Also fix bid being leaked while being at it.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-28 22:10:33 +04:00
Gerd Hoffmann
99aec0123c qemu-char: use ChardevBackendKind in CharDriver
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-28 22:10:33 +04:00
Gerd Hoffmann
e668287d44 qemu-char: don't leak opts on error
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-28 22:10:33 +04:00
Gerd Hoffmann
fdca2124ad qemu-char: print notification to stderr
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-28 22:10:33 +04:00
Gerd Hoffmann
20c397607c qemu-char: use more specific error_setg_* variants
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-28 22:10:33 +04:00
Gerd Hoffmann
e859eda585 qemu-char: check optional fields using has_*
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-28 22:10:33 +04:00
liguang
e990a39328 qemu-char: use bool in qemu_chr_open_socket and simplify code a bit
Local variables is_* should be bool by usage.
While at it, simplify the logic/code a bit.

Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-21 22:52:50 +04:00
Michael Tokarev
4efeabbbe8 create qemu_openpty_raw() helper function and move it to a separate file
In two places qemu uses openpty() which is very system-dependent,
and in both places the pty is switched to raw mode as well.
Make a wrapper function which does both steps, and move all the
system-dependent complexity into a separate file, together
with static/local implementations of openpty() and cfmakeraw()
from qemu-char.c.

It is in a separate file, not part of oslib-posix.c, because
openpty() often resides in -lutil which is not linked to
every program qemu builds.

This change removes #including of <pty.h>, <termios.h>
and other rather specific system headers out of qemu-common.h,
which isn't a place for such specific headers really.

This version has been verified to build correctly on Linux,
OpenBSD, FreeBSD and OpenIndiana.  On the latter it lets qemu
to be built with gtk gui which were not possible there due to
missing openpty() and cfmakeraw().

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Tested-by: Andreas Färber <andreas.faerber@web.de>
2013-06-14 14:28:43 +04:00
Michael Tokarev
c58e6201fa qemu-char: remove a few needless #includes
This removes <syslog.h> since we don't use
syslogging, and removes second, solaris-specific,
include of <net/if.h> (which is included in
a common part of the file)

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-06-11 23:45:43 +04:00
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
Gerd Hoffmann
60d95386ab chardev: fix "info chardev" output
Fill unset CharDriverState->filename with the backend name, so
'info chardev' will return at least the chardev type.  Don't
touch it in case the chardev init function filled it already,
like the socket+pty chardevs do for example.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-05-27 12:47:28 +02:00
Gerd Hoffmann
3022e6b472 Revert "chardev: Get filename for new qapi backend"
Does not handle chardevs created via chardev-add monitor command.

This reverts commit 2b22002599.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-05-27 12:47:17 +02:00
Lei Li
2b22002599 chardev: Get filename for new qapi backend
This patch sets the filename when the new qapi backend
init from opts.

The previous patch and discussions as link below:

http://patchwork.ozlabs.org/patch/243896/

If anyone who have better idea to fix this please let
me know your suggestions.

Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Message-id: 1369132079-11377-3-git-send-email-lilei@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-22 07:40:10 -05:00
Lei Li
6a85e60cb9 chardev: Make the name of memory device consistent
Now we have memory char device, but the backend name of it
is a little confusion. We actually register it by 'memory', but
the description in qemu-option, the name of open functions
and the new api backend called it 'ringbuf'. It should keep
consistent. This patch named it all to 'memory'.

Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1369132079-11377-2-git-send-email-lilei@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-22 07:40:10 -05:00
Peter Crosthwaite
3d1bba2091 glib: Fix some misuses of gsize/size_t types
This unbreaks cross compile builds:

configure --target-list="i386-softmmu" --cpu=i386

When building on a 64bit machine.

Reported-by: David Holsgrove <david.holsgrove@xilinx.com>
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Message-id: 926326e96fd8685d74e9d5bf430fe4ad97a55289.1369191585.git.peter.crosthwaite@xilinx.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-22 07:40:09 -05:00
Lei Li
08d0ab3fe6 chardev: Make consistent with udp device for new qapi backend
When register and open a chardev udp, the backend name should be udp
not dgram, and we do not have backend dgram in the chardev list. This
patch makes the new qapi udp backend consistent with the original
udp device.

Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Message-id: 1369032665-18159-2-git-send-email-lilei@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-20 08:20:07 -05:00
Paolo Bonzini
7791dba3ec portability: pty.h is glibc-specific
This should fix building the GTK+ front-end on BSDs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1368533121-30796-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-05-14 08:53:18 -05:00
Hans de Goede
79f2007578 qemu-char: Set foo_tag = 0 when returning FALSE from callbacks
While reviewing some patches I found this problem where tcp_chr_accept
does not clear listen_tag when returning FALSE, leading to a double
g_source_remove of the underlying source. Not really a problem unless the id
gets re-used in between, but still something we should fix.

While at it I've also reviewed all the other code in qemu-char.c for
similar problems and found that pty_chr_timer has the same problem.

Cc: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1366890782-10311-1-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-25 14:45:47 -05:00
Paolo Bonzini
2b316774f6 qemu-char: do not operate on sources from finalize callbacks
Due to a glib bug, the finalize callback is called with the GMainContext
lock held.  Thus, any operation on the context from the callback will
cause recursive locking and a deadlock.  This happens, for example,
when a client disconnects from a socket chardev.

The fix for this is somewhat ugly, because we need to forego polymorphism
and implement our own function to destroy IOWatchPoll sources.  The
right thing to do here would be child sources, but we support older
glib versions that do not have them.  Not coincidentially, glib developers
found and fixed the deadlock as part of implementing child sources.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Sander Eikelenboom <linux@eikelenboom.it>
Message-id: 1366385529-10329-5-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-22 08:52:21 -05:00
Paolo Bonzini
cdbf6e1659 qemu-char: correct return value from chr_read functions
Even if a CharDriverState's source is blocked by the front-end,
it must not be dropped. The IOWatchPoll that wraps it will take
care of adding and removing it to the main loop.  Only remove
the source when the channel is closed; and in that case, make sure
that the wrapping IOWatchPoll is removed too.

These should just be theoretical bugs.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1366385529-10329-4-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-22 08:52:20 -05:00
Paolo Bonzini
85a67692d0 qemu-char: simplify pty polling
There is no need to use a timer and pty_chr_read to detect a connected
pty.  It is simpler to just call g_poll periodically and check for POLLHUP.
It is done once per second, and only if the pty is disconnected, so it
is cheap enough.

Tested with "-monitor pty" and "-serial mon:pty", both of which work
correctly and do not freeze QEMU.  (How to test ptys?  "socat -,raw,echo=0
/dev/pts/4,raw").

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1366385529-10329-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-22 08:52:20 -05:00
Paolo Bonzini
910b63682e qemu-char: use consistent idiom for removing sources
Always check that the source is active, and zero the tag afterwards.

The occurrence in pty_chr_state will trigger with the next patch, the
others are just theoretical.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1366385529-10329-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-22 08:52:20 -05:00
Anthony Liguori
4ceb193d30 Merge remote-tracking branch 'bonzini/hw-dirs' into staging
* bonzini/hw-dirs:
  exec: remove useless declarations from memory-internal.h
  memory: move core typedefs to qemu/typedefs.h
  include: avoid useless includes of exec/ headers
  sysemu: avoid proliferation of include/ subdirectories
  tpm: reorganize headers and split hardware part
  configure: fix TPM logic
  acpi.h: make it self contained
  acpi: move declarations from pc.h to acpi.h
  hw: Add lost ARM core again
  Fix failure to create q35 machine
  Add linux-headers to QEMU_INCLUDES
  arm: fix location of some include files

Conflicts:
	configure

aliguori: trivial conflict in configure output

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-15 17:06:04 -05:00
Paolo Bonzini
dccfcd0e5f sysemu: avoid proliferation of include/ subdirectories
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2013-04-15 18:19:25 +02:00
Paolo Bonzini
0ca5aa4f4c qemu-char: another io_add_watch_poll fix
After attaching the source, we have to remove the reference we hold
to it, because we do not hold anymore a pointer to the source.

If we do not do this, removing the source will not finalize it and
will not drop the "real" I/O watch source.

This showed up when backporting the new flow control patches to older
versions of QEMU that still used select.  The whole select then failed
with EBADF (poll instead will reporting POLLNVAL on a single pollfd)
and QEMU froze.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1365600207-21685-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-15 10:22:05 -05:00
Paolo Bonzini
1e885b2527 qemu-char: really fix behavior on can_read = 0
I misread the glib manual, g_source_remove does not let you re-attach
the source later.  This behavior (called "blocking" the source in glib)
is present in glib's source code, but private and not available outside
glib; hence, we have to resort to re-creating the source every time.

In fact, g_source_remove and g_source_destroy are the same thing,
except g_source_destroy is O(1) while g_source_remove scans a potentially
very long list of GSources in the current main loop.  Ugh.  Better
use g_source_destroy explicitly, and leave "tags" to those dummies who
cannot track their pointers' lifetimes.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1365426195-12596-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-08 10:38:41 -05:00
Paolo Bonzini
d185c094b4 qemu-char: eliminate busy waiting on can_read returning zero
The character backend refactoring introduced an undesirable busy wait.
The busy wait happens if can_read returns zero and there is data available
on the character device's file descriptor.  Then, the I/O watch will
fire continuously and, with TCG, the CPU thread will never run.

    1) Char backend asks front end if it can write
    2) Front end says no
    3) poll() finds the char backend's descriptor is available
    4) Goto (1)

What we really want is this (note that step 3 avoids the busy wait):

    1) Char backend asks front end if it can write
    2) Front end says no
    3) poll() goes on without char backend's descriptor
    4) Goto (1) until qemu_chr_accept_input() called

    5) Char backend asks front end if it can write
    6) Front end says yes
    7) poll() finds the char backend's descriptor is available
    8) Backend handler called

After this patch, the IOWatchPoll source and the watch source are
separated.  The IOWatchPoll is simply a hook that runs during the prepare
phase on each main loop iteration.  The hook adds/removes the actual
source depending on the return value from can_read.

A simple reproducer is

    qemu-system-i386 -serial mon:stdio

... followed by banging on the terminal as much as you can. :)  Without
this patch, emulation will hang.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1365177573-11817-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-05 12:53:07 -05:00
Luiz Capitulino
4bf0bb8014 chardev: drop the Memory chardev driver
It's not used anymore since the last commit.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
2013-04-05 08:42:29 -04:00
Hans de Goede
456d606923 qemu-char: Call fe_claim / fe_release when not using qdev chr properties
chardev-frontends need to explictly check, increase and decrement the
avail_connections "property" of the chardev when they are not using a
qdev-chardev-property for the chardev.

This fixes things like:
qemu-kvm -chardev stdio,id=foo -device isa-serial,chardev=foo \
  -mon chardev=foo

Working, where they should fail. Most of the changes here are due to
old hardware emulation code which is using serial_hds directly rather then
a qdev-chardev-property.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364412581-3672-3-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-04 19:21:25 -05:00
Hans de Goede
44c473decd qemu-char: Add qemu_chr_fe_claim / _release helper functions
Add qemu_chr_fe_claim / _release helper functions for properly dealing with
avail_connections.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364412581-3672-2-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-04-04 19:21:25 -05:00
Anthony Liguori
162cbbd173 Merge remote-tracking branch 'luiz/queue/qmp' into staging
# By Stefan Hajnoczi
# Via Luiz Capitulino
* luiz/queue/qmp:
  chardev: clear O_NONBLOCK on SCM_RIGHTS file descriptors
  qemu-socket: set passed fd non-blocking in socket_connect()
  net: ensure "socket" backend uses non-blocking fds
  oslib-posix: rename socket_set_nonblock() to qemu_set_nonblock()
2013-04-02 14:07:35 -05:00
Stefan Hajnoczi
9b938c7262 chardev: clear O_NONBLOCK on SCM_RIGHTS file descriptors
When we receive a file descriptor over a UNIX domain socket the
O_NONBLOCK flag is preserved.  Clear the O_NONBLOCK flag and rely on
QEMU file descriptor users like migration, SPICE, VNC, block layer, and
others to set non-blocking only when necessary.

This change ensures we don't accidentally expose O_NONBLOCK in the QMP
API.  QMP clients should not need to get the non-blocking state
"correct".

A recent real-world example was when libvirt passed a non-blocking TCP
socket for migration where we expected a blocking socket.  The source
QEMU produced a corrupted migration stream since its code did not cope
with non-blocking sockets.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-04-02 11:47:37 -04:00
Stefan Hajnoczi
f9e8cacc55 oslib-posix: rename socket_set_nonblock() to qemu_set_nonblock()
The fcntl(fd, F_SETFL, O_NONBLOCK) flag is not specific to sockets.
Rename to qemu_set_nonblock() just like qemu_set_cloexec().

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2013-04-02 11:47:37 -04:00
Anthony Liguori
684a096eaf qemu-char: rewrite io_channel_send_all and drop the '_all' suffix
The current code is oddly written and have equally odd semantics.
Despite the '_all' suffix, upon EAGAIN the result will be a partial
write but instead of returning the partial write, we return EAGAIN.

Change the behavior to write as much as we can until we get an EAGAIN
returning a partial write if we do.

Reported-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1364575190-731-1-git-send-email-aliguori@us.ibm.com
2013-04-02 08:13:58 -05:00
Hans de Goede
a59bcd31c9 qemu-char: add_handlers: Don't re-send the be_open event on unregister
Resending the be_open event only is useful when a frontend is registering, not
when it is unregistering.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-9-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-03-27 10:26:49 -05:00
Hans de Goede
85d91e3295 qemu-char: Move incrementing of avail_connections to qdev-properties-system
The decrement of avail_connections is done in qdev-properties-system move
the increment there too for proper balancing of the calls.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-8-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-03-27 10:26:49 -05:00
Hans de Goede
574b711a92 qemu-char: Consolidate guest_close/guest_open into a set_fe_open callback
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-7-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-03-27 10:26:49 -05:00
Hans de Goede
8e25daa87a qemu-char: Cleanup: consolidate fe_open/fe_close into fe_set_open
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-6-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-03-27 10:26:49 -05:00
Hans de Goede
190832289f qemu-char: Automatically do fe_open / fe_close on qemu_chr_add_handlers
Most frontends can't really determine if the guest actually has the frontend
side open. So lets automatically generate fe_open / fe_close as soon as a
frontend becomes ready (as signalled by calling qemu_chr_add_handlers) /
becomes non ready (as signalled by setting all handlers to NULL).

And allow frontends which can actually determine if the guest is listening to
opt-out of this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-5-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-03-27 10:26:49 -05:00
Hans de Goede
c0c4bd2cfa qemu-char: Add fe_open tracking
Add tracking of the fe_open state to struct CharDriverState.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-4-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-03-27 10:26:49 -05:00