qcow2: Gather clusters in a looping loop

Instead of just checking once in exactly this order if there are
dependendies, non-COW clusters and new allocation, this starts looping
around these. This way we can, for example, gather non-COW clusters after
new allocations as long as the host cluster offsets stay contiguous.

Once handle_dependencies() is extended so that COW areas of in-flight
allocations can be overwritten, this allows to continue with gathering
other clusters (we wouldn't be able to do that without this change
because we would have missed a possible second dependency in one of the
next clusters).

This means that in the typical sequential write case, we can combine the
COW overwrite of one cluster with the allocation of the next cluster as
soon as something like Delayed COW gets actually implemented. It is only
by avoiding splitting requests this way that Delayed COW actually starts
improving performance noticably.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
block: Fix direct use of protocols as driver for bdrv_open()

bdrv_open_common() implements direct use of protocols by copying the
pre-opened BlockDriverStates to bs using bdrv_swap(). It did however
first set some fields in bs, which end up in file after the swap. When
bdrv_open() destroys file, it appears to be open, and because it isn't,
qemu could segfault while trying to close it.

Reorder the operations to return immediately in such cases so that file
is correctly detected as closed.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
trace: [tracetool] Explicitly identify public backends

Public backends are those printed by "--list-backends" and thus considered valid
by the configure script.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
trace: Provide a generic tracing event descriptor

Uses tracetool to generate a backend-independent tracing event description
(struct TraceEvent).

The values for such structure are generated with the non-public "events"
backend ("events-c" frontend).

The generation of the defines to check if an event is statically enabled is also
moved to the "events" backend ("events-h" frontend).

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
trace: Provide a detailed event control interface

This interface decouples event obtaining from interaction.

Events can be obtained through three different methods:

* identifier
* name
* simple wildcard pattern

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
trace: [monitor] Use new event control interface

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
trace: [default] Port to generic event information and new control interface

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
trace: [simple] Port to generic event information and new control interface

The backend is forced to dump event numbers using 64 bits, as TraceEventID is
an enum.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
trace: [stderr] Port to generic event information and new control interface

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
trace: rebuild generated-events.o when configuration changes

Make sure to rebuild generated-events.o when ./configure options change.
This prevents linker errors when a stale generated-events.o gets linked
with code compiled against fresh headers.  For example, try building
with ./configure --enable-trace-backend=stderr followed by ./configure
--enable-trace-backend=dtrace.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
.gitignore: add trace/generated-events.[ch]

Don't display autogenerated files in git-status(1).

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
.gitignore: rename trace/generated-tracers.dtrace

For a while the file was called trace/generated-tracers-dtrace.dtrace
but today it's called trace/generated-tracers.dtrace.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
vl: add runstate_set tracepoint

This patch enables us to know RunState transition. It will be userful
for investigation when the trouble occured in special event such like
live migration, shutdown, suspend, and so on.

Signed-off-by: Kazuya Saito <saito.kazuya@jp.fujitsu.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Merge remote-tracking branch 'stefanha/tracing' into staging

# By Lluís Vilanova (7) and others
# Via Stefan Hajnoczi
* stefanha/tracing:
  vl: add runstate_set tracepoint
  .gitignore: rename trace/generated-tracers.dtrace
  .gitignore: add trace/generated-events.[ch]
  trace: rebuild generated-events.o when configuration changes
  trace: [stderr] Port to generic event information and new control interface
  trace: [simple] Port to generic event information and new control interface
  trace: [default] Port to generic event information and new control interface
  trace: [monitor] Use new event control interface
  trace: Provide a detailed event control interface
  trace: Provide a generic tracing event descriptor
  trace: [tracetool] Explicitly identify public backends
Merge remote-tracking branch 'stefanha/block' into staging

# By Kevin Wolf (22) and Peter Lieven (1)
# Via Stefan Hajnoczi
* stefanha/block: (23 commits)
  block: Fix direct use of protocols as driver for bdrv_open()
  qcow2: Gather clusters in a looping loop
  qcow2: Move cluster gathering to a non-looping loop
  qcow2: Allow requests with multiple l2metas
  qcow2: Use byte granularity in qcow2_alloc_cluster_offset()
  qcow2: Prepare handle_alloc/copied() for byte granularity
  qcow2: handle_copied(): Implement non-zero host_offset
  qcow2: handle_copied(): Get rid of keep_clusters parameter
  qcow2: handle_copied(): Get rid of nb_clusters parameter
  qcow2: Factor out handle_copied()
  qcow2: Clean up handle_alloc()
  qcow2: Finalise interface of handle_alloc()
  qcow2: handle_alloc(): Get rid of keep_clusters parameter
  qcow2: handle_alloc(): Get rid of nb_clusters parameter
  qcow2: Factor out handle_alloc()
  qcow2: Decouple cluster allocation from cluster reuse code
  qcow2: Change handle_dependency to byte granularity
  qcow2: Improve check for overlapping allocations
  qcow2: Handle dependencies earlier
  qcow2: Remove bogus unlock of s->lock
  ...
virtio-balloon: add the virtio-balloon device.

Create virtio-balloon which extends virtio-device, so it can be connected on
virtio-bus.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-id: 1364377755-15508-2-git-send-email-fred.konrad@greensocs.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
virtio-balloon-pci: switch to the new API.

Here the virtio-balloon-pci is modified for the new API. The device
virtio-balloon-pci extends virtio-pci. It creates and connects a
virtio-balloon during the init. The properties are not changed.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-id: 1364377755-15508-3-git-send-email-fred.konrad@greensocs.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
virtio-balloon-ccw: switch to the new API.

Here the virtio-balloon-ccw is modified for the new API. The device
virtio-balloon-ccw extends virtio-ccw-device as before. It creates and
connects a virtio-balloon during the init. The properties are not modified.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-id: 1364377755-15508-4-git-send-email-fred.konrad@greensocs.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
virtio-balloon: cleanup: init and exit function.

This remove old init and exit function as they are no longer needed.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-id: 1364377755-15508-5-git-send-email-fred.konrad@greensocs.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
virtio-balloon: cleanup: QOM casts.

As the virtio-balloon-pci is switched to the new API, we can use QOM
casts.

Signed-off-by: KONRAD Frederic <fred.konrad@greensocs.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-id: 1364377755-15508-6-git-send-email-fred.konrad@greensocs.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>