The header is not necessary, given that the simple backend does not define any
inlined tracing routines.
Signed-off-by: NLluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

When running with trace backend e.g. "simple" the writer thread needs to be
implemented in the same process context as the trace points that will be
processed. Under libvirtd control, qemu gets first started in daemonized
mode to privide its capabilities. Creating the writer thread in the initial
process context then leads to a dead lock because the thread gets termined
together with the initial parent. (-daemonize)
Signed-off-by: NMichael Mueller <mimu@linux.vnet.ibm.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>
[minor whitespace fixes]
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

* qemu-kvm/uq/master:
  kvm: always update the MPX model specific register
  KVM: fix addr type for KVM_IOEVENTFD
  KVM: Retry KVM_CREATE_VM on EINTR
  mempath prefault: fix off-by-one error
  kvm: x86: Separately write feature control MSR on reset
  roms: Flush icache when writing roms to guest memory
  target-i386: clear guest TSC on reset
  target-i386: do not special case TSC writeback
  target-i386: Intel MPX

Conflicts:
	exec.c

aliguori: fix trivial merge conflict in exec.c
Signed-off-by: NAnthony Liguori <aliguori@amazon.com>

* otubo/seccomp:
  seccomp: add some basic shared memory syscalls to the whitelist
  seccomp: add mkdir() and fchmod() to the whitelist

Message-id: 1390231004-18392-1-git-send-email-otubo@linux.vnet.ibm.com
Signed-off-by: NAnthony Liguori <aliguori@amazon.com>

Initial patch for QEMU GTK support on Windows

# gpg: Signature made Mon 20 Jan 2014 11:37:58 AM PST using RSA key ID FAD62069
# gpg: Can't check signature: public key not found

* sweil/tags/for_anthony:
  gtk: Support keyboard translation for hosts running Windows

Message-id: 1390246909-18757-1-git-send-email-sw@weilnetz.de
Signed-off-by: NAnthony Liguori <aliguori@amazon.com>

hda-codec: disable streams on reset

# gpg: Signature made Tue 21 Jan 2014 02:17:12 AM PST using RSA key ID D3E87138
# gpg: Can't check signature: public key not found

* kraxel/tags/pull-audio-2:
  hda-codec: disable streams on reset

Message-id: 1390299589-5082-1-git-send-email-kraxel@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@amazon.com>

usb core+hid: add support for microsoft os descriptors

# gpg: Signature made Tue 21 Jan 2014 02:21:29 AM PST using RSA key ID D3E87138
# gpg: Can't check signature: public key not found

* kraxel/tags/pull-usb-2:
  usb-hid: add microsoft os descriptor support
  usb: add support for microsoft os descriptors

Message-id: 1390299772-5368-1-git-send-email-kraxel@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@amazon.com>

* bonzini/scsi-next:
  scsi: Support TEST UNIT READY in the dummy LUN0
  block: add .bdrv_reopen_prepare() stub for iscsi
  virtio-scsi: Prevent assertion on missed events
  virtio-scsi: Cleanup of I/Os that never started
  scsi: Assign cancel_io vector for scsi_disk_emulate_ops

Conflicts:
	block/iscsi.c

aliguori: resolve trivial merge conflict in block/iscsi.c
Signed-off-by: NAnthony Liguori <aliguori@amazon.com>

Block patches

# gpg: Signature made Fri 24 Jan 2014 08:40:53 AM PST using RSA key ID C88F2FD6
# gpg: Can't check signature: public key not found

* kwolf/tags/for-anthony: (93 commits)
  block: Switch bdrv_io_limits_intercept() to byte granularity
  qemu-iotests: Test pwritev RMW logic
  qemu-io: New command 'sleep'
  blkdebug: Make required alignment configurable
  iscsi: Set bs->request_alignment
  block: Make bdrv_pwrite() a bdrv_prwv_co() wrapper
  block: Make bdrv_pread() a bdrv_prwv_co() wrapper
  block: Change coroutine wrapper to byte granularity
  block: Assert serialisation assumptions in pwritev
  block: Align requests in bdrv_co_do_pwritev()
  block: Allow wait_serialising_requests() at any point
  block: Make overlap range for serialisation dynamic
  block: Generalise and optimise COR serialisation
  block: Make zero-after-EOF work with larger alignment
  block: Allow waiting for overlapping requests between begin/end
  block: Switch BdrvTrackedRequest to byte granularity
  block: Introduce bdrv_co_do_pwritev()
  block: write: Handle COR dependency after I/O throttling
  block: Introduce bdrv_aligned_pwritev()
  block: Introduce bdrv_co_do_preadv()
  ...

Message-id: 1390584136-24703-1-git-send-email-kwolf@redhat.com
Signed-off-by: NAnthony Liguori <aliguori@amazon.com>

Request sizes used to be rounded down to the next sector boundary,
allowing to bypass the I/O limit. Now all requests are accounted for
with their exact byte size.
Reported-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

There is no easy way to check that a request correctly waits for a
different request. With a sleep command we can at least approximate it.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The new 'align' option of blkdebug can be used in order to emulate
backends with a required 4k alignment on hosts which only really require
512 byte alignment.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The iSCSI backend already gets the block size from the READ CAPACITY
command it sends.  Save it so that the generic block layer gets it
too.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Instead of implementing the alignment adjustment here, use the now
existing functionality of bdrv_co_do_pwritev().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Instead of implementing the alignment adjustment here, use the now
existing functionality of bdrv_co_do_preadv().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

If a request calls wait_serialising_requests() and actually has to wait
in this function (i.e. a coroutine yield), other requests can run and
previously read data (like the head or tail buffer) could become
outdated. In this case, we would have to restart from the beginning to
read in the updated data.

However, we're lucky and don't actually need to do that: A request can
only wait in the first call of wait_serialising_requests() because we
mark it as serialising before that call, so any later requests would
wait. So as we don't wait in practice, we don't have to reload the data.

This is an important assumption that may not be broken or data
corruption will happen. Document it with some assertions.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

This patch changes bdrv_co_do_pwritev() to actually be what its name
promises. If requests aren't properly aligned, it performs a RMW.

Requests touching the same block are serialised against the RMW request.
Further optimisation of this is possible by differentiating types of
requests (concurrent reads should actually be okay here).
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

We can only have a single wait_serialising_requests() call per request
because otherwise we can run into deadlocks where requests are waiting
for each other. The same is true when wait_serialising_requests() is not
at the very beginning of a request, so that other requests can be issued
between the start of the tracking and wait_serialising_requests().

Fix this by changing wait_serialising_requests() to ignore requests that
are already (directly or indirectly) waiting for the calling request.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

Copy on Read wants to serialise with all requests touching the same
cluster, so wait_serialising_requests() rounded to cluster boundaries.
Other users like alignment RMW will have different requirements, though
(requests touching the same sector), so make it dynamic.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

Change the API so that specific requests can be marked serialising. Only
these requests are checked for overlaps then.

This means that during a Copy on Read operation, not all requests
overlapping other requests are serialised any more, but only those that
actually overlap with the specific COR request.

Also remove COR from function and variable names because this
functionality can be useful in other contexts.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

Odd file sizes could make bdrv_aligned_preadv() shorten the request in
non-aligned ways. Fix it by rounding to the required alignment instead
of 512 bytes.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

Previously, it was not possible to use wait_for_overlapping_requests()
between tracked_request_begin()/end() because it would wait for itself.

Ignore the current request in the overlap check and run more of the
bdrv_co_do_preadv/pwritev code with a BdrvTrackedRequest present.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

This is going to become the bdrv_co_do_preadv() equivalent for writes.
In this patch, however, just a function taking byte offsets is created,
it doesn't align anything yet.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

First waiting for all COR requests to complete and calling the
throttling function afterwards means that the request could be delayed
and we still need to wait for the COR request even if it was issued only
after the throttled write request.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

This separates the part of bdrv_co_do_writev() that needs to happen
before the request is modified to match the backend alignment, and a
part that needs to be executed afterwards and passes the request to the
BlockDriver.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

Similar to bdrv_pread(), which aligns byte-aligned request to 512 byte
sectors, bdrv_co_do_preadv() takes a byte-aligned request and aligns it
to the alignment specified in bs->request_alignment.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

This separates the part of bdrv_co_do_readv() that needs to happen
before the request is modified to match the backend alignment, and a
part that needs to be executed afterwards and passes the request to the
BlockDriver.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

Add a bs->request_alignment field that contains the required
offset/length alignment for I/O requests and fill it in the raw block
drivers. Use ioctls if possible, else see what alignment it takes for
O_DIRECT to succeed.

While at it, also expose the memory alignment requirements, which may be
(and in practice are) different from the disk alignment requirements.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

The alignment field is now set to the value that is promised to the
guest, rather than required by the host.  The next patches will make
QEMU aware of the host-provided values, so make this clear.

The alignment is also not about memory buffers, but about the sectors on
the disk, change the documentation of the field.

At this point, the field is set by the device emulation, but completely
ignored by the block layer.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

bs->buffer_alignment is set by the device emulation and contains the
logical block size of the guest device. This isn't something that the
block layer should know, and even less something to use for determining
the right alignment of buffers to be used for the host.

The new BlockLimits field opt_mem_alignment tells the qemu block layer
the optimal alignment to be used so that no bounce buffer must be used
in the driver.

This patch may change the buffer alignment from 4k to 512 for all
callers that used qemu_blockalign() with the top-level image format
BlockDriverState. The value was never propagated to other levels in the
tree, so in particular raw-posix never required anything else than 512.

While on disks with 4k sectors direct I/O requires a 4k alignment,
memory may still be okay when aligned to 512 byte boundaries. This is
what must have happened in practice, because otherwise this would
already have failed earlier. Therefore I don't expect regressions even
with this intermediate state. Later, raw-posix can implement the hook
and expose a different memory alignment requirement.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

For an O_DIRECT request to succeed, it's not only necessary that all
base addresses in the qiov are aligned, but also that each length in it
is aligned.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

The functions used by qemu_memalign() require an alignment that is at
least sizeof(void*). Adjust it if it is too small.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoît Canet <benoit@irqsave.net>

When reopening with different flags, or when backing files disappear
from the chain, the limits may change. Make sure they get updated in
these cases.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoît Canet <benoit@irqsave.net>

When there is a format driver between the backend, it's not guaranteed
that exposing the opt_transfer_length for the format driver results in
the optimal requests (because of fragmentation etc.), but it can't make
things worse, so let's just do it.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NWenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoît Canet <benoit@irqsave.net>

This function separates filling the BlockLimits from bdrv_open(), which
allows it to call it from other operations which may change the limits
(e.g. modifications to the backing file chain or bdrv_reopen)
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

bdrv_commit() could return 0 or 1 on success, depending on whether or
not the last sector was allocated in the overlay and whether the overlay
format had a .bdrv_make_empty callback.

Most callers ignored it, but qemu-img commit would print an error
message while the operation actually succeeded.

Also clean up the handling of I/O errors to return the real error code
instead of -EIO.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

This updates the documentation for commiting snapshot images.
Specifically, this highlights what happens when the base image
is either smaller or larger than the snapshot image being committed.

In the case of the base image being smaller, it is resized to the
larger size of the snapshot image.  In the case of the base image
being larger, it is not resized automatically, but once the commit
has completed it is safe for the user to truncate the base image.
Signed-off-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>