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 the old SysBus init function and use instance_init
* Call qemu_chr_add_handlers in the realize callback
* Use qdev chardev prop instead of qemu_char_get_next_serial
* Add lm32_uart_create function to create lm32 uart device
Signed-off-by: xiaoqiang zhao <zxq_yx_007@163.com>
Message-Id: <1464158344-12266-5-git-send-email-zxq_yx_007@163.com>
Tested-by: Michael Walle <michael@walle.cc>
Acked-by: Michael Walle <michael@walle.cc>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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: 1453832250-766-5-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>
After previous Peter patch, they are redundant. This way we don't
assign them except when needed. Once there, there were lots of case
where the ".fields" indentation was wrong:
.fields = (VMStateField []) {
and
.fields = (VMStateField []) {
Change all the combinations to:
.fields = (VMStateField[]){
The biggest problem (appart from aesthetics) was that checkpatch complained
when we copy&pasted the code from one place to another.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
qemu_chr_fe_write() may return EAGAIN. Therefore, use
qemu_chr_fe_write_all().
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
