We should guarantee that RAM will not be modified while VM has a stopped
state, otherwise it can lead to negative consequences during post-copy
migration. In RUN_STATE_FINISH_MIGRATE step, it's expected that RAM on
source side will not be modified as this could lead to non-consistent vm state
on the destination side. Also RAM access during postcopy-ram migration with
enabled release-ram capability can lead to sad consequences.
Let's add enable_backend() callback to avoid undesirable virtioqueue changes
in the guest memory.
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Message-Id: <20170919120733.22020-1-pbutsykin@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In case of a backend change, the handler functions and the watch have
to be reset.
Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <1499342940-56739-12-git-send-email-anton.nefedov@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
frontends should avoid accessing CharDriver struct where possible
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: <1499342940-56739-6-git-send-email-anton.nefedov@virtuozzo.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>
Move all the frontend struct and methods to a seperate unit. This avoids
accidentally mixing backend and frontend calls, and helps with readabilty.
Make qemu_chr_replay() a macro shared by both char and char-fe.
Export qemu_chr_write(), and use a macro for qemu_chr_write_all()
(nb: yes, CharBackend is for char frontend :)
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
So they are all in one place. The following patch will move serial &
parallel declarations to the respective headers.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Pick a uniform chardev type name.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.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>
The virtio-console.c file handles both serial consoles
and interactive consoles, since they're backed by the
same device model.
Since serial devices are expected to be reliable and
need to notify the guest when the backend is opened
or closed, the virtio-console.c file wires up support
for chardev events. This affects both serial consoles
and interactive consoles, using a network connection
based chardev backend such as 'socket', but not when
using a PTY based backend or plain 'file' backends.
When the host side is not connected the handle_output()
method in virtio-serial-bus.c will drop any data sent
by the guest, before it even reaches the virtio-console.c
code. This means that if the chardev has a logfile
configured, the data will never get logged.
Consider for example, configuring a x86_64 guest with a
plain UART serial port
-chardev socket,id=charserial1,host=127.0.0.1,port=9001,server,nowait,logfile=console1.log,logappend=on
-device isa-serial,chardev=charserial1,id=serial1
vs a s390 guest which has to use the virtio-console port
-chardev socket,id=charconsole1,host=127.0.0.1,port=9000,server,nowait,logfile=console2.log,logappend=on
-device virtconsole,chardev=charconsole1,id=console1
The isa-serial one gets data written to the log regardless
of whether a client is connected, while the virtioconsole
one only gets data written to the log when a client is
connected.
There is no need for virtio-serial-bus.c to aggressively
drop the data for console devices, as the chardev code is
prefectly capable of discarding the data itself.
So this patch changes virtconsole devices so that they
are always marked as having the host side open. This
ensures that the guest OS will always send any data it
has (Linux virtio-console hvc driver actually ignores
the host open state and sends data regardless, but we
should not rely on that), and also prevents the
virtio-serial-bus code prematurely discarding data.
The behaviour of virtserialport devices is *not* changed,
only virtconsole, because for the former, it is important
that the guest OSknow exactly when the host side is opened
/ closed so it can do any protocol re-negotiation that may
be required.
Fixes bug: https://bugs.launchpad.net/qemu/+bug/1599214
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1470241360-3574-2-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@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: 1453832250-766-15-git-send-email-peter.maydell@linaro.org
When the virtio serial is writable, notify the chardev backend
with qemu_chr_accept_input().
Signed-off-by: Marc-André Lureau <marcandre.lureau@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
On FreeBSD polling a master pty while the other end is not connected
with G_IO_OUT only results in an endless wait. This is different from
the Linux behaviour, that returns immediately. In order to demonstrate
this, I have the following example code:
http://xenbits.xen.org/people/royger/test_poll.c
When executed on Linux:
$ ./test_poll
In callback
On FreeBSD instead, the callback never gets called:
$ ./test_poll
So, in order to workaround this, poll the source with G_IO_HUP (which
makes the code behave the same way on both Linux and FreeBSD).
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Cc: Michael Tokarev <mjt@tls.msk.ru>
Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: xen-devel@lists.xenproject.org
[Add hw/char/cadence_uart.c too. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Libvirt wants to know about the guest-side connection state of some
virtio-serial ports (in particular the one(s) assigned to guest agent(s)).
Report such states with a new monitor event.
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1080376
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Commit 0399a3819b (virtio-console: QOM
cast cleanup for VirtConsole) broke virtserialport since it shares
functions and state struct with virtconsole. Let virtconsole inherit
from virtserialport, and use virtserialport type for casting.
Note that virtio-serial-port is the abstract base type in
virtio-serial-bus.c, whereas virtserialport is the user-instantiatable
type in virtio-console.c. Therefore using TYPE_VIRTIO_CONSOLE_SERIAL_PORT.
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Acked-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
virtconsole and virtserialport are identical in every other aspect
except for the distinguishing VirtIOSerialPortClass::is_console field.
Cc: qemu-stable@nongnu.org
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Message-id: 1375313326-14966-1-git-send-email-afaerber@suse.de
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This is necessary so that we get properly woken up to write the rest.
This patch also changes the len argument to the have_data callback, to
avoid doing an unsigned signed comparison.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
