Add flags to io_writev and introduce io_flush as optional callback to
QIOChannelClass, allowing the implementation of zero copy writes by
subclasses.

How to use them:
- Write data using qio_channel_writev*(...,QIO_CHANNEL_WRITE_FLAG_ZERO_COPY),
- Wait write completion with qio_channel_flush().

Notes:
As some zero copy write implementations work asynchronously, it's
recommended to keep the write buffer untouched until the return of
qio_channel_flush(), to avoid the risk of sending an updated buffer
instead of the buffer state during write.

As io_flush callback is optional, if a subclass does not implement it, then:
- io_flush will return 0 without changing anything.

Also, some functions like qio_channel_writev_full_all() were adapted to
receive a flag parameter. That allows shared code between zero copy and
non-zero copy writev, and also an easier implementation on new flags.

Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20220513062836.965425-3-leobras@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

Cleaned up with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20220506134911.2856099-5-armbru@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

The qemu_*block() functions are meant to be be used with sockets (the
win32 implementation expects SOCKET)

Over time, those functions where used with Win32 SOCKET or
file-descriptors interchangeably. But for portability, they must only be
used with socket-like file-descriptors. FDs can use
g_unix_set_fd_nonblocking() instead.

Rename the functions with "socket" in the name to prevent bad usages.

This is effectively reverting commit f9e8cacc ("oslib-posix:
rename socket_set_nonblock() to qemu_set_nonblock()").

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Those calls are either for non-socket fd, or are POSIX-specific. Use the
dedicated GLib API. (qemu_set_nonblock() is for socket-like)

(this is a preliminary patch before renaming qemu_set_nonblock())

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-33-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

It is only needed by char-pty.

Fix the code style while at it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-6-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

After the return from tcp_chr_recv, tcp_chr_sync_read calls into a
function which eventually makes a system call and may clobber errno.

Make a copy of errno right after tcp_chr_recv and restore the errno on
return from tcp_chr_sync_read.

Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Message-Id: <20211111153354.18807-4-rvkagan@yandex-team.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

tcp_chr_recv communicates the specific error condition to the caller via
errno.  However, after setting it, it may call into some system calls or
library functions which can clobber the errno.

Avoid this by moving the errno assignment to the end of the function.

Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Message-Id: <20211111153354.18807-3-rvkagan@yandex-team.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

The following patches are going to use CharSocket as a base class for
sockets that are created with a given fd (without a given address).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

Object is supposed to be freed by invoking obj->free, and not
obj->instance_finalize. This would lead to use-after-free followed by
double free in object_unref/object_finalize.

Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20211117142349.836279-1-d-tatianin@yandex-team.ru>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

While there are a number of uses in the code-base of the exit(0)
pattern it gets in the way of clean exit which can do all of it's
house-keeping. In particular it was reported that you can crash
plugins this way because TCG can still be running on other threads
when the atexit callback is called.

Use qmp_quit() instead which takes care of some housekeeping before
triggering the shutdown.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reported-by: Lukas Jünger <lukas.junger@greensocs.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20211026102234.3961636-19-alex.bennee@linaro.org>

Add meson feature options for Spice and Spice protocol, and move
detection logic out of configure.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20211007102453.978041-1-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20211007130829.632254-13-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Simple unions predate flat unions.  Having both complicates the QAPI
schema language and the QAPI generator.  We haven't been using simple
unions in new code for a long time, because they are less flexible and
somewhat awkward on the wire.

To prepare for their removal, convert simple union SocketAddressLegacy
to an equivalent flat one, with existing enum SocketAddressType
replacing implicit enum type SocketAddressLegacyKind.  Adds some
boilerplate to the schema, which is a bit ugly, but a lot easier to
maintain than the simple union feature.

Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210917143134.412106-9-armbru@redhat.com>

"chr_option_parsed" is only implemented by the "mux" chardev, we can
specialize the code there to avoid the needless generic class method.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

If a chardev has a logfile the file is opened using
qemu_open_old() which does the job, but since @errp is not
propagated into qemu_open_internal() we lose much more accurate
error and just report "Unable to open logfile $errno".  When
using plain files, it's probably okay as nothing complex is
happening behind the curtains. But the problem becomes more
prominent when passing an "/dev/fdset/XXX" path since much more
needs to be done.

The fix is to use qemu_create() which passes @errp further down.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <f34ee80866e6f591bcb98401dee27682f5543fca.1629190206.git.mprivozn@redhat.com>

Report:
  "Chardev with id 'char2' already exists"
Rather than:
  "Failed to add chardev 'char2': duplicate yank instance"

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Description from Daniel P. Berrangé:
> The original code reported:
>
>  "attempt to add duplicate property 'char2' to object (type 'container')"
>
> Since adding yank support, the current code reports
>
>  "duplicate yank instance"
>
> With this patch applied it now reports:
>
>  "Failed to add chardev 'char2': duplicate yank instance"
>
> This is marginally better, but still not great, not that the original
> error was great either.
>
> It would be nice if we could report
>
>   "chardev with id 'char2' already exists"

Related to:
https://bugzilla.redhat.com/show_bug.cgi?id=1984721



Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

The "serial" chardev calls qemu_chr_open_fd() with the same fd. This
may lead to double-close as each QIOChannel owns the fd.

Instead, share the reference to the same QIOChannel.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

The "file" chardev may call qemu_chr_open_fd() with fd_in=-1. This may
cause invalid system calls, as the QIOChannel is assumed to be properly
initialized later on.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Create child sources for the different streams, and dispatch on the
parent source with the synthesized conditions.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Since commit 9894dc0c "char: convert
from GIOChannel to QIOChannel", the first argument to the watch callback
can actually be a QIOChannel, which is not a GIOChannel (but a QEMU
Object).

Even though we never used that pointer, change the callback type to warn
the users. Possibly a better fix later, we may want to store the
callback and call it from intermediary functions.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Better reflect the command line version of the socket address arguments,
following the now recommended long-form opt=on syntax.

Complement/fixes commit 9d902d51 "chardev: do not use short form boolean
options in non-QemuOpts character device descriptions".

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

The chardev-spicevmc class was not listed in chardev/spice.c, causing
"-chardev spicevmc" to fail when modules are enabled.

Reported-by: Frederic Bezies <fredbezies@gmail.com>
Fixes: 9f4a0f09 ("modules: use modinfo for qom load", 2021-07-09)
Resolves: //gitlab.com/qemu-project/qemu/-/issues/488
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210719164435.1227794-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jose R. Ziviani <jziviani@suse.de>
Message-Id: <20210624103836.2382472-8-kraxel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Avoid accessing QCryptoTLSCreds internals by using
the qcrypto_tls_creds_check_endpoint() helper.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

Commit e50caf4a ("tracing: convert documentation to rST")
converted docs/devel/tracing.txt to docs/devel/tracing.rst.

We still have several references to the old file, so let's fix them
with the following command:

  sed -i s/tracing.txt/tracing.rst/ $(git grep -l docs/devel/tracing.txt)

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210517151702.109066-2-sgarzare@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

This patch adds support for clipboard messages to the qemu vdagent
implementation, which allows the guest exchange clipboard data with
qemu.  Clipboard support can be enabled/disabled using the new
'clipboard' parameter for the vdagent chardev.  Default is off.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20210519053940.1888907-1-kraxel@redhat.com
Message-Id: <20210519053940.1888907-7-kraxel@redhat.com>

This patch adds support for mouse messages to the vdagent
implementation.  This can be enabled/disabled using the new
'mouse' parameter for the vdagent chardev.  Default is on.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20210519053940.1888907-1-kraxel@redhat.com
Message-Id: <20210519053940.1888907-6-kraxel@redhat.com>

Stop including sysemu/sysemu.h in files that don't need it.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20210416171314.2074665-2-thuth@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

When changing from chardev-socket (which supports yank) to
chardev-socket again, it fails, because the new chardev attempts
to register a new yank instance. This in turn fails, as there
still is the yank instance from the current chardev. Also,
the old chardev shouldn't unregister the yank instance when it
is freed.

To fix this, now the new chardev only registers a yank instance if
the current chardev doesn't support yank and thus hasn't registered
one already. Also, when the old chardev is freed, it now only
unregisters the yank instance if the new chardev doesn't need it.

If the initialization of the new chardev fails, it still has
chr->handover_yank_instance set and won't unregister the yank
instance when it is freed.

s->registered_yank is always true here, as chardev-change only works
on user-visible chardevs and those are guraranteed to register a
yank instance as they are initialized via
chardev_new()
 qemu_char_open()
  cc->open() (qmp_chardev_open_socket()).

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Li Zhang <li.zhang@cloud.ionos.com>
Message-Id: <9637888d7591d2971975188478bb707299a1dc04.1617127849.git.lukasstraub2@web.de>

Always pass the id to chardev_new, since it is needed to register
the yank instance for the chardev. Also, after checking that
nothing calls chardev_new with id=NULL, assert() that id!=NULL.

This fixes a crash when using chardev-change to change a chardev
to chardev-socket, which attempts to register a yank instance.
This in turn tries to dereference the NULL-pointer.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Li Zhang <li.zhang@cloud.ionos.com>
Message-Id: <3e669b6c160aa7278e37c4d95e0445574f96c7b7.1617127849.git.lukasstraub2@web.de>

Move object_property_try_add_child out of chardev_new into it's
callers. This is a preparation for the next patches to fix yank
with the chardev-change case.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Li Zhang <li.zhang@cloud.ionos.com>
Message-Id: <b2a5092ec681737bc3a21ea16f3c00848b277521.1617127849.git.lukasstraub2@web.de>

Remove dependency on qiochannel by removing yank_generic_iochannel and
letting migration and chardev use their own yank function for
iochannel.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20ff143fc2db23e27cd41d38043e481376c9cec1.1616521341.git.lukasstraub2@web.de>

Both callers use callbacks that don't do anything when they are called
for CLI aliases. Instead of passing the cli_alias parameter, just don't
call the callbacks for aliases in the first place.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210311164253.338723-4-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

QAPI doesn't know the aliases 'tty' and 'parport' and there is no
reason to prefer them to the real names of the backends 'serial' and
'parallel'.

Since warnings are not allowed in 'make check' output, we can't test
the deprecated alias any more. Remove it from test-char.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210311164253.338723-3-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

The aliases "tty" and "parport" are only valid on the command line, QMP
commands like chardev-add don't know them. query-chardev-backends should
describe QMP and therefore not include them in the list of available
backends.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210311164253.338723-2-kwolf@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

This only makes sense conceptually when used with listener chardevs.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

The "delay" option was introduced as a way to enable Nagle's algorithm
with ",nodelay".  Since the short form for boolean options has now been
deprecated, introduce a more properly named "nodelay" option.  The "delay"
option remains as an undocumented option.

"delay" and "nodelay" are mutually exclusive.  Because the check is
done at consumption time, the code also rejects them if one of the
two is specified via -set.

Based-on: <20210226080526.651705-1-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Options such as "-gdb" or "-serial" accept a part-QemuOpts part-parsed-by-hand
character device description.  Do not use short form boolean options in the
QemuOpts part.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>