The point of writing a macro embedded in a 'do { ... } while (0)'
loop (particularly if the macro has multiple statements or would
otherwise end with an 'if' statement) is so that the macro can be
used as a drop-in statement with the caller supplying the
trailing ';'. Although our coding style frowns on brace-less 'if':
if (cond)
statement;
else
something else;
that is the classic case where failure to use do/while(0) wrapping
would cause the 'else' to pair with any embedded 'if' in the macro
rather than the intended outer 'if'. But conversely, if the macro
includes an embedded ';', then the same brace-less coding style
would now have two statements, making the 'else' a syntax error
rather than pairing with the outer 'if'. Thus, even though our
coding style with required braces is not impacted, ending a macro
with ';' makes our code harder to port to projects that use
brace-less styles.
The change should have no semantic impact. I was not able to
fully compile-test all of the changes (as some of them are
examples of the ugly bit-rotting debug print statements that are
completely elided by default, and I didn't want to recompile
with the necessary -D witnesses - cleaning those up is left as a
bite-sized task for another day); I did, however, audit that for
all files touched, all callers of the changed macros DID supply
a trailing ';' at the callsite, and did not appear to be used
as part of a brace-less conditional.
Found mechanically via: $ git grep -B1 'while (0);' | grep -A1 \\\\
Signed-off-by: Eric Blake <eblake@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20171201232433.25193-7-eblake@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Frontends should have an interface to setup the handler of a backend change.
The interface will be used in the next commits
Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1499342940-56739-3-git-send-email-anton.nefedov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
No need to keep explicit_fe_open around if it affects only a
qemu_chr_fe_set_handlers(). Use an additional argument instead.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-24-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In most cases, front ends do not care about the side effect of
CharBackend, so we can simply skip the checks and call the qemu_chr_fe
functions even without associated CharDriver.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-20-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This also switches from qemu_chr_add_handlers() to
qemu_chr_fe_set_handlers(). Note that qemu_chr_fe_set_handlers() now
takes the focus when fe_open (qemu_chr_add_handlers() did take the
focus)
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-16-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu_chr_accept_input() and qemu_chr_disconnect() are only used by
frontend, so use qemu_chr_fe prefix.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-14-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Store the property in a CharBackend instead of CharDriverState*. This
also replace systematically chr by chr.chr to access the
CharDriverState*. The following patches will replace it with calls to
qemu_chr_fe CharBackend functions.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20161022095318.17775-12-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The qemu_chr_fe_write method will return -1 on EAGAIN if the
chardev backend write would block. Almost no callers of the
qemu_chr_fe_write() method check the return value, instead
blindly assuming data was successfully sent. In most cases
this will lead to silent data loss on interactive consoles,
but in some cases (eg RNG EGD) it'll just cause corruption
of the protocol being spoken.
We unfortunately can't fix the virtio-console code, due to
a bug in the Linux guest drivers, which would cause the
entire Linux kernel to hang if we delay processing of the
incoming data in any way. Fixing this requires first fixing
the guest driver to not hold spinlocks while writing to the
hvc device backend.
Fixes bug: https://bugs.launchpad.net/qemu/+bug/1586756
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1473170165-540-4-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* drop qemu_char_get_next_serial and use chardev prop
* change affected board code to use the new way
Signed-off-by: xiaoqiang zhao <zxq_yx_007@163.com>
Message-id: 1465028065-5855-5-git-send-email-zxq_yx_007@163.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.
This commit was created with scripts/clean-includes.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-36-git-send-email-peter.maydell@linaro.org
Device models aren't supposed to go on fishing expeditions for
backends. They should expose suitable properties for the user to set.
For onboard devices, board code sets them.
A number of sysbus devices pick up block backends in their init() /
instance_init() methods with drive_get_next() instead: sl-nand,
milkymist-memcard, pl181, generic-sdhci.
Likewise, a number of sysbus devices pick up character backends in
their init() / realize() methods with qemu_char_get_next_serial():
cadence_uart, digic-uart, etraxfs,serial, lm32-juart, lm32-uart,
milkymist-uart, pl011, stm32f2xx-usart, xlnx.xps-uartlite.
All these mistakes are already marked FIXME. See the commit that
added these FIXMEs for a more detailed explanation of what's wrong.
Fortunately, only machines ppce500 and pseries-* support -device with
sysbus devices, and none of the devices above is supported with these
machines.
Set cannot_instantiate_with_device_add_yet to preserve our luck.
Cc: Andrzej Zaborowski <balrogg@gmail.com>
Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Michael Walle <michael@walle.cc>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Character devices defined with -serial and -parallel are for board
initialization to wire up. Board code examines serial_hds[] and
parallel_hds[] to find them, and creates devices with their qdev
chardev properties set accordingly.
Except a few devices go on a fishing expedition for a suitable backend
instead of exposing a chardev property for board code to set: they use
serial_hds[] (often via qemu_char_get_next_serial()) or parallel_hds[]
in their realize() or init() method to connect to a backend.
Picking up backends that way works when the devices are created by
board code. But it's inappropriate for -device or device_add. Not
only is it inconsistent with how the other characrer device models
work (they connect to a backend explicitly identified by a "chardev"
property), it breaks when the backend has been picked up by the board
or a previous -device / device_add already.
Example:
$ qemu-system-ppc64 -M bamboo -S -device i82378 -device pc87312 -device pc87312
qemu-system-ppc64: -device pc87312: Property 'isa-parallel.chardev' can't take value 'parallel0', it's in use
Mark them with suitable FIXME comments.
Cc: Li Guang <lig.fnst@cn.fujitsu.com>
Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Cc: Antony Pavlov <antonynpavlov@gmail.com>
Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Cc: "Andreas Färber" <andreas.faerber@web.de>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This patch adds the stm32f2xx USART controller
(UART also uses the same controller).
Signed-off-by: Alistair Francis <alistair@alistair23.me>
Reviewed-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 762c6c0d2a41d574932bc4445ec9bfffe6da8798.1424175342.git.alistair@alistair23.me
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
