QAPI will require glib/python, but for now the guest agent is the only
user. For now, make these dependencies an explicit guest agent one, and
give users the option to disable it if need be.

Once QAPI is adopted in core QEMU code, we would basically revert this
patch.
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NBrad Smith <brad@comstyle.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

The system emulation code was not merged before the branch.
Let's leave that work for the next release.
Signed-off-by: NRichard Henderson <rth@twiddle.net>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

With vhost_net="" (most non-Linux hosts), configure prints an
error message:

test: 2551: =: unexpected operator

Fix this and similar code by adding the missing "".

Cc: Wolfgang Mauerer <wolfgang.mauerer@siemens.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NStefan Weil <weil@mail.berlios.de>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Migrating after unplugging a virtio-balloon device resulted in an error
message on the destination:

Unknown savevm section or instance '0000:00:04.0/virtio-balloon' 0
load of migration failed

Fix this by unregistering the section on device unplug.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>

Add an exit handler that will free up RAM after a virtio-balloon device
is unplugged.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>

Negative balloon values don't make sense, reject them and throw a qerror
with QERR_INVALID_PARAMETER_VALUE.
Reported-by: NMike Cao <bcao@redhat.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>

Multiple balloon registrations are not allowed; check if the
registration with the qemu balloon api succeeded.  If not, fail the
device init.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>

Multiple balloon devices don't make sense; disallow more than one
registration attempt to register handlers.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>

Signed-off-by: NAmit Shah <amit.shah@redhat.com>

Signed-off-by: NAmit Shah <amit.shah@redhat.com>

Passing on '0' as ballooning target to indicate retrieval of stats is
bad API.  It also makes 'balloon 0' in the monitor cause a segfault.
Have two different functions handle the different functionality instead.

Detailed explanation from Markus's review:

1. do_info_balloon() is an info_async() method.  It receives a callback
   with argument, to be called exactly once (callback frees the
   argument).  It passes the callback via qemu_balloon_status() and
   indirectly through qemu_balloon_event to virtio_balloon_to_target().

   virtio_balloon_to_target() executes its balloon stats half.  It
   stores the callback in the device state.

   If it can't send a stats request, it resets stats and calls the
   callback right away.

   Else, it sends a stats request.  The device model runs the callback
   when it receives the answer.

   Works.

2. do_balloon() is a cmd_async() method.  It receives a callback with
   argument, to be called when the command completes.  do_balloon()
   calls it right before it succeeds.  Odd, but should work.

   Nevertheless, it passes the callback on via qemu_ballon() and
   indirectly through qemu_balloon_event to virtio_balloon_to_target().

   a. If the argument is non-zero, virtio_balloon_to_target() executes
      its balloon half, which doesn't use the callback in any way.

      Odd, but works.

   b. If the argument is zero, virtio_balloon_to_target() executes its
      balloon stats half, just like in 1.  It either calls the callback
      right away, or arranges for it to be called later.

      Thus, the callback runs twice: use after free and double free.

Test case: start with -S -device virtio-balloon, execute "balloon 0" in
human monitor.  Runs the callback first from virtio_balloon_to_target(),
then again from do_balloon().
Reported-by: NMike Cao <bcao@redhat.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>

Separate out the code to retrieve balloon info from the code that sets
balloon values.

This will be used to separate the two callbacks from balloon.c and help
cope with 'balloon 0' on the monitor.  Currently, 'balloon 0' causes a
segfault in monitor_resume().
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>

Replace:
  if (foo) {
    ...
  } else {
    return 0;
  }

by

  if (!foo) {
    return 0;
  }
  ...
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>

Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>

balloon.h had function declarations for a couple of functions that are
local to balloon.c.  Make them static.

Drop the 'qemu_' prefix for balloon.c-local variables, and make them
static.
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>

If we're already in a coroutine, there is no reason to use the synchronous
version of block layer functions when a coroutine one exists. This makes
bdrv_read/write/flush use bdrv_co_* when used inside a coroutine.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The QEMU keyboard and mouse reports themselves as full speed devices,
though they are actually low speed devices. Until this is fixed, claim that
we are supporting full speed devices.
Acked-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NMichael Walle <michael@walle.cc>
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>

In order to be able to transparently replace bdrv_read calls by bdrv_co_read,
reading beyond EOF must produce zeros instead of short reads for AIO, too.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Now that AsyncContexts don't exist any more, we can use one global bottom half
for restarting coroutines instead of allocating a new one every time (before
removing AsyncContexts, the problem with having a global BH was that it had to
belong to a single AsyncContexts and wouldn't be executed in a different one -
which leads to deadlocks)
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The purpose of AsyncContexts was to protect qcow and qcow2 against reentrancy
during an emulated bdrv_read/write (which includes a qemu_aio_wait() call and
can run AIO callbacks of different requests if it weren't for AsyncContexts).

Now both qcow and qcow2 are protected by CoMutexes and AsyncContexts can be
removed.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The old qcow format is another user of the AsyncContext infrastructure.
Converting it to coroutines (and therefore CoMutexes) allows to remove
AsyncContexts.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>

In order to be able to call bdrv_co_readv/writev for drivers that don't
implement the functions natively, add an emulation that uses the AIO functions
to implement them.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Use the bdrv_co_readv/writev callbacks to implement bdrv_aio_readv/writev and
bdrv_read/write if a driver provides the coroutine version instead of the
synchronous or AIO version.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Add new block driver callbacks bdrv_co_readv/writev, which work on a
QEMUIOVector like bdrv_aio_*, but don't need a callback. The function may only
be called inside a coroutine, so a block driver implementing this interface can
yield instead of blocking during I/O.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Add a microbenchmark for coroutine create, enter, and return (aka
lifecycle).  This is a useful benchmark because users are expected to
create many coroutines, one per I/O request for example, and we
therefore need to provide good performance in that scenario.

To run:

  make test-coroutine
  ./test-coroutine --benchmark-lifecycle 20000000

This will do 20,000,000 coroutine create, enter, return iterations and
print the resulting time.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

To run automated tests for coroutines:

  make test-coroutine
  ./test-coroutine

On success the program terminates with exit status 0.  On failure an
error message is written to stderr and the program exits with exit
status 1.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Commit b14ef7c9
introduced cpu_unassigned_access() function. On Sparc,
the function does not restore AREG0 used for global CPUState
on function exit, causing bugs with non-faulting unassigned
memory accesses. Alpha, Microblaze and MIPS are not affected.

Fix by restoring AREG0 on exit. Remove excess saving by
do_unassigned_access() functions.

Also ignore unassigned accesses outside of CPU context.
Reported-by: NBob Breuer <breuerr@mc.net>
Tested-by: NBob Breuer <breuerr@mc.net>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

On platforms that don't support makecontext(3) use gthread based
coroutine implementation.

Darwin has makecontext(3) but getcontext(3) is stubbed out to return
ENOTSUP.  Andreas Färber <andreas.faerber@web.de> debugged this and
contributed the ./configure test which solves the issue for Darwin/ppc64
(and ppc) v10.5.

[Original patch by Aneesh, made consistent with coroutine-ucontext.c and
switched to GStaticPrivate by Stefan.  Tested on Linux and OpenBSD.]
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Asynchronous code is becoming very complex.  At the same time
synchronous code is growing because it is convenient to write.
Sometimes duplicate code paths are even added, one synchronous and the
other asynchronous.  This patch introduces coroutines which allow code
that looks synchronous but is asynchronous under the covers.

A coroutine has its own stack and is therefore able to preserve state
across blocking operations, which traditionally require callback
functions and manual marshalling of parameters.

Creating and starting a coroutine is easy:

  coroutine = qemu_coroutine_create(my_coroutine);
  qemu_coroutine_enter(coroutine, my_data);

The coroutine then executes until it returns or yields:

  void coroutine_fn my_coroutine(void *opaque) {
      MyData *my_data = opaque;

      /* do some work */

      qemu_coroutine_yield();

      /* do some more work */
  }

Yielding switches control back to the caller of qemu_coroutine_enter().
This is typically used to switch back to the main thread's event loop
after issuing an asynchronous I/O request.  The request callback will
then invoke qemu_coroutine_enter() once more to switch back to the
coroutine.

Note that if coroutines are used only from threads which hold the global
mutex they will never execute concurrently.  This makes programming with
coroutines easier than with threads.  Race conditions cannot occur since
only one coroutine may be active at any time.  Other coroutines can only
run across yield.

This coroutines implementation is based on the gtk-vnc implementation
written by Anthony Liguori <anthony@codemonkey.ws> but it has been
significantly rewritten by Kevin Wolf <kwolf@redhat.com> to use
setjmp()/longjmp() instead of the more expensive swapcontext() and by
Paolo Bonzini <pbonzini@redhat.com> for Windows Fibers support.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Signed-off-by: NFrediano Ziglio <freddy77@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NFrediano Ziglio <freddy77@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NFrediano Ziglio <freddy77@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Instead of using its own definitions scsi-disk should
be using the device type of the parent device.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Sanitize SCSI command definitions.
Add _10 suffix to READ_CAPACITY, WRITE_VERIFY, VERIFY, READ_LONG,
WRITE_LONG, and WRITE_SAME.
Add new command definitions for LOCATE_10, UNMAP, VARLENGTH_CDB,
WRITE_FILEMARKS_16, EXTENDED_COPY, ATA_PASSTHROUGH, ACCESS_CONTROL_IN,
ACCESS_CONTROL_OUT, COMPARE_AND_WRITE, VERIFY_16, SYNCHRONIZE_CACHE_16,
LOCATE_16, ERASE_16, WRITE_LONG_16, LOAD_UNLOAD, VERIFY_12.
Remove invalid definition of WRITE_LONG_2.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

REZERO_UNIT command is obsolete. Remove support for it.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

SET_WINDOW command is vendor-specific only.
So we shouldn't try to emulate it.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>