The new thread pool will use semaphores instead of condition
variables, because QemuCond does not have qemu_cond_timedwait.
(I also like it more this way).
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Since linux-aio already uses an eventfd, converting it to use the
EventNotifier-based API simplifies the code even though it is not
meant to be portable.
Reviewed-by: NAnthony Liguori <anthony@codemonkey.ws>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Some cleanups can now be made, now that the main loop does not anymore need
hooks into the bottom half code.
Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This lets us remove the hooks for the main loop in async.c.
Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

In the current code, this is done by qemu_set_fd_handler2, which is
called by qemu_aio_set_fd_handler.  We need to keep the same behavior
even after removing the call to qemu_set_fd_handler2.
Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

With this change async.c does not rely anymore on any service from
main-loop.c, i.e. it is completely self-contained.
Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This lets AioContexts be used (optionally) with a glib main loop.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The Win32 implementation will only accept EventNotifiers, thus a few
drivers are disabled under Windows.  EventNotifiers are a good match
for the GSource implementation, too, because the Win32 port of glib
allows to place their HANDLEs in a GPollFD.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This adds a GPollFD to each AioHandler.  It will then be possible to
attach these GPollFDs to a GSource, and from there to the main loop.
aio_wait examines the GPollFDs and avoids calling select() if any
is set (similar to what it does if bottom halves are available).
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This will be used when polling the GSource attached to an AioContext.
Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Otherwise, there could be a case where io_flush accesses freed
memory because it should not have been called.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

With this patch, I/O handlers (including event notifier handlers) can be
attached to a single AioContext.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Start introducing AioContext, which will let us remove globals from
aio.c/async.c, and introduce multiple I/O threads.

The bottom half functions now take an additional AioContext argument.
A bottom half is created with a specific AioContext that remains the
same throughout the lifetime.  qemu_bh_new is just a wrapper that
uses a global context.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This adds to aio.c a platform-independent API based on EventNotifiers, that
can be used by both POSIX and Win32.
Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Otherwise, chardevs will not be able to create a bottom half as soon
as that will require an AioContext.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This takes the eventfd emulation code from the main loop.  When the
EventNotifier is used for the main loop too, we need this compatibility
code.

Without CONFIG_EVENTFD, event_notifier_get_fd is only usable for the
"read" side of the notifier, for example to set a select() handler.

The return value of event_notifier_set changes to the cleaner 0/-errno.
No caller is actually checking the return value.
Reviewed-by: NAnthony Liguori <anthony@codemonkey.ws>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

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

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

It is only used by QEMU itself, do not build it into the tests.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

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

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

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

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

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

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

qemu-tool.c has its own (largeish) set of dependencies.  Weak aliases
can be placed directly where people use them, and do not contribute
to increasing the dependencies of generic utility files.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This is simpler and more portable.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

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

This removes the dependency of cutils.c on iov.c, and lets us remove
iov.o from several builds.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Commit ad0b5321 forgot to add
QEMU_MADV_HUGEPAGE macros for when CONFIG_MADVISE is not defined.
This broke the build for Windows. Fix it.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

* bonzini/nbd-next: (30 commits)
  qmp: add NBD server commands
  block: add close notifiers
  block: prepare code for adding block notifiers
  qemu-sockets: add socket_listen, socket_connect, socket_parse
  tests: do not include tools-obj-y Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  qemu-sockets: return InetSocketAddress from inet_parse
  qapi: add socket address types
  build: add QAPI files to the tools
  vnc: drop QERR_VNC_SERVER_FAILED
  qemu-sockets: add error propagation to Unix socket functions
  qemu-sockets: add error propagation to inet_parse
  qemu-sockets: add error propagation to inet_dgram_opts
  qemu-sockets: add error propagation to inet_connect_addr
  qemu-sockets: include strerror or gai_strerror output in error messages
  vnc: add error propagation to vnc_display_open
  vnc: reorganize code for reverse mode
  vnc: introduce a single label for error returns
  vnc: avoid Yoda conditionals
  qemu-ga: ask and print error information from qemu-sockets
  nbd: ask and print error information from qemu-sockets
  ...

Adding an NBD server inside QEMU is trivial, since all the logic is
in nbd.c and can be shared easily between qemu-nbd and QEMU itself.
The main difference is that qemu-nbd serves a single unnamed export,
while QEMU serves named exports.
Acked-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The first user of close notifiers will be the embedded NBD server.
It would be possible to use them to do some of the ad hoc processing
(e.g. for block jobs and I/O limits) that is currently done by
bdrv_close.
Acked-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

There is no reason in principle to skip job cancellation and draining
of pending I/O when there is no medium in the disk.  Do these unconditionally,
which also prepares the code for the next patch.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

These are QAPI-friendly versions of the qemu-sockets functions.  They
support IP sockets, Unix sockets, and named file descriptors, using a
QAPI union to dispatch to the correct function.
Reviewed-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

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

Reviewed-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Acked-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>