W32 does not support line buffering, but it supports unbuffered output.

Unbuffered output is better for writing to qemu.log than fully buffered
output because it also shows the latest log messages when an application
crash occurs.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Since commit 1d14ffa9 (in 2005),
QEMU applications on W32 don't use the default SDL compiler flags:

Instead of a GUI application, a console application is created.

This has disadvantages (there is always an empty console window) and
no obvious reason, so this patch removes the strange flag modification.

The SDL GUI applications still can be run from a console window
and even send stdout and stderr to that console by setting environment
variable SDL_STDIO_REDIRECT=no.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Enable build by default PIE / read-only relocation sections for the QEMU
binaries on OpenBSD amd64/i386.
Signed-off-by: NBrad Smith <brad@comstyle.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

This bug was spotted by cppcheck.

Using g_try_malloc0 (as does the linux-user code) fixes this.

v2:
Use g_free in bsdload.c, too. Thanks to Peter Maydell for this hint.
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Ignore attempts to complete non-existent IRQs; this fixes a buffer
overrun if the guest writes a bad value to the GICC_EOIR register.
(This case is UNPREDICTABLE so ignoring it is a valid choice.)
Note that doing nothing if the guest writes 1023 to this register
is not in fact a change in behaviour: the old code would also
always do nothing in this case but in a non-obvious way.
(The buffer overrun was noted by Coverity, see bug 887883.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

Drop the distinction between armv4l/armv4b in the $cpu variable
(ie host cpu type) in favour of calling everything 'arm'. This
makes it the same as the ARCH setting and removes some special
casing. The only thing we were using the distinction for was to
decide which endianness to use in cross compilation; do a cpp
define check there instead.
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

spapr_populate_pci_devices() containd a loop with PCI_NUM_REGIONS (7)
iterations.  However this overruns the 'bars' global array, which only has
6 elements. In fact we only want to run this loop for things listed in the
bars array, so this patch corrects the loop bounds to reflect that.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

Don't call arm_translate_init() (which allocates TCG resources)
unless TCG is enabled.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

Clarify some slightly misleading comments in the Thumb decoder's
handling of the memory hint space -- in particular one code path
marked as 'UNPREDICTABLE or unallocated hint' also includes some
legitimate preload instructions.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

Two of the calls to hw_error() in arm_timer.c contain the wrong function name.

As suggested by Andreas Färber, use the C99 standard __func__ macro to
get the correct name, instead of putting the name directly into the code.
Signed-off-by: NPeter Chubb <peter.chubb@nicta.com.au>
Signed-off-by: NAndrzej Zaborowski <andrew.zaborowski@intel.com>

Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Many places in QEMU call qemu_aio_flush() to complete all pending
asynchronous I/O.  Most of these places actually want to drain all block
requests but there is no block layer API to do so.

This patch introduces the bdrv_drain_all() API to wait for requests
across all BlockDriverStates to complete.  As a bonus we perform checks
after qemu_aio_wait() to ensure that requests really have finished.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Debugging a reentrant request deadlock was fun but in the future we need
a quick and obvious way of detecting such bugs.  Add an assert that
checks we are not about to deadlock when waiting for another request.
Suggested-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Cases beyond the end of the disk image are only implemented for block
drivers that do not provide .bdrv_co_is_allocated().  It's worth making
these cases generic so that block drivers that do implement
.bdrv_co_is_allocated() also get them for free.
Suggested-by: NMark Wu <wudxw@linux.vnet.ibm.com>
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Now that bdrv_co_is_allocated() is available we can use it instead of
the synchronous bdrv_is_allocated() interface.  This is a follow-up that
Kevin Wolf <kwolf@redhat.com> pointed out after applying the series that
introduces bdrv_co_is_allocated().

It is safe to make cow_read() a coroutine_fn because its only caller is
a coroutine_fn.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch adds the -drive copy-on-read=on|off command-line option:

  copy-on-read=on|off
  copy-on-read is "on" or "off" and enables whether to copy read backing
  file sectors into the image file.  Copy-on-read avoids accessing the
  same backing file sectors repeatedly and is useful when the backing
  file is over a slow network.  By default copy-on-read is off.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Detect overlapping requests and remember to align to cluster boundaries
if the image format uses them.  This assumes that allocating I/O is
performed in cluster granularity - which is true for qcow2, qed, etc.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

When copy-on-read is enabled it is necessary to wait for overlapping
requests before issuing new requests.  This prevents races between the
copy-on-read and a write request.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The bdrv_enable_copy_on_read()/bdrv_disable_copy_on_read() functions can
be used to programmatically enable or disable copy-on-read for a block
device.  Later patches add the actual copy-on-read logic.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The block layer does not know about pending requests.  This information
is necessary for copy-on-read since overlapping requests must be
serialized to prevent races that corrupt the image.

The BlockDriverState gets a new tracked_request list field which
contains all pending requests.  Each request is a BdrvTrackedRequest
record with sector_num, nb_sectors, and is_write fields.

Note that request tracking is always enabled but hopefully this extra
work is so small that it doesn't justify adding an enable/disable flag.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

It's common to wake up all waiting coroutines.  Introduce the
qemu_co_queue_restart_all() function to do this instead of looping over
qemu_co_queue_next() in every caller.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Add macros for aligning a number to a multiple, for example:

QEMU_ALIGN_DOWN(500, 2000) = 0
QEMU_ALIGN_UP(500, 2000) = 2000

Since ALIGN_UP() is a common macro name use the QEMU_* namespace prefix.
Hopefully this will protect us from included headers that leak something
with a similar name.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch introduces the public bdrv_co_is_allocated() interface which
can be used to query image allocation status while the VM is running.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Now that all block drivers have been converted to
.bdrv_co_is_allocated() we can drop .bdrv_is_allocated().

Note that the public bdrv_is_allocated() interface is still available
but is in fact a synchronous wrapper around .bdrv_co_is_allocated().
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The cow block driver does not keep internal state for cluster lookups.
This means it is safe to perform cluster lookups in coroutine context
without risk of race conditions that corrupt internal state.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

It is trivial to switch from the synchronous .bdrv_is_allocated()
interface to .bdrv_co_is_allocated() since vdi_is_allocated() does not
block.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

It is trivial to switch from the synchronous .bdrv_is_allocated()
interface to .bdrv_co_is_allocated() since vvfat_is_allocated() does not
block.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The qcow2, qcow, and vmdk block drivers are based on coroutines.  They have a
coroutine mutex which protects internal state.  We can convert the
.bdrv_is_allocated() function to .bdrv_co_is_allocated() by holding the mutex
around the cluster lookup operation.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The bdrv_qed_is_allocated() function is a synchronous wrapper around
qed_find_cluster(), which performs the cluster lookup.  In order to
convert the synchronous function to a coroutine function we yield
instead of using qemu_aio_wait().  Note that QED's cache is already safe
for parallel requests so no locking is needed.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch adds the .bdrv_co_is_allocated() interface which is identical
to .bdrv_is_allocated() but runs in coroutine context.  Running in
coroutine context implies that other coroutines might be performing I/O
at the same time.   Therefore it must be safe to run while the following
BlockDriver functions are in-flight:

    .bdrv_co_readv()
    .bdrv_co_writev()
    .bdrv_co_flush()
    .bdrv_co_is_allocated()

The new .bdrv_co_is_allocated() interface is useful because it can be
used when a VM is running, whereas .bdrv_is_allocated() is a synchronous
interface that does not cope with parallel requests.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

There is no need for bdrv_commit() to use the BlockDriver
.bdrv_is_allocated() interface directly.  Converting to the public
interface gives us the freedom to drop .bdrv_is_allocated() entirely in
favor of a new .bdrv_co_is_allocated() in the future.
Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

If the bdrv_read() of the snapshot's L1 table fails, return the right
error code and make sure that the old L1 table is still loaded and we
don't break the BlockDriverState completely.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

First the snapshot must be deleted and only then the refcounts can be
decreased.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>

The refcount updates must be moved so that in the worst case we can get
cluster leaks, but refcounts may never be too low.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>