This patch add shrinking of the image file for qcow2. As a result, this allows
us to reduce the virtual image size and free up space on the disk without
copying the image. Image can be fragmented and shrink is done by punching holes
in the image file.
Signed-off-by: NPavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 20170918124230.8152-4-pbutsykin@virtuozzo.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Whenever l2/refcount table clusters are discarded from the file we can
automatically drop unnecessary content of the cache tables. This reduces
the chance of eviction useful cache data and eliminates inconsistent data
in the cache with the data in the file.
Signed-off-by: NPavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 20170918124230.8152-3-pbutsykin@virtuozzo.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

The flag is additional precaution against data loss. Perhaps in the future the
operation shrink without this flag will be blocked for all formats, but for now
we need to maintain compatibility with raw.
Signed-off-by: NPavel Butsykin <pbutsykin@virtuozzo.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 20170918124230.8152-2-pbutsykin@virtuozzo.com
[mreitz: Added a missing space to a warning]
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Migration capabilities should be enabled on both source and
destination qemu processes.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This involves a temporary read-write reopen if the backing file link in
the middle of a backing file chain should be changed and is therefore a
good test for the latest bdrv_reopen() vs. op blockers fixes.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

If we switch between read-only and read-write, the permissions that
image format drivers need on bs->file change, too. Make sure to update
the permissions during bdrv_reopen().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

We will calculate the required new permissions in the prepare stage of a
reopen. Required permissions of children can be influenced by the
changes made to their parents, but parents are independent from their
children. This means that permissions need to be calculated top-down. In
order to achieve this, queue parents before their children rather than
queuing the children first.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

When new permissions are calculated during bdrv_reopen(), they need to
be based on the state of the graph as it will be after the reopen has
completed, not on the current state of the involved nodes.

This patch makes bdrv_is_writable() optionally accept a BlockReopenQueue
from which the new flags are taken. This is then used for determining
the new bs->file permissions of format drivers as soon as we add the
code to actually pass a non-NULL reopen queue to the .bdrv_child_perm
callbacks.

While moving bdrv_is_writable(), make it static. It isn't used outside
block.c.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

In the context of bdrv_reopen(), we'll have to look at the state of the
graph as it will be after the reopen. This interface addition is in
preparation for the change.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

In the context of bdrv_reopen(), we'll have to look at the state of the
graph as it will be after the reopen. This interface addition is in
preparation for the change.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

qemu-io provides a 'reopen' command that allows switching from writable
to read-only access. We need to make sure that we don't try to keep
write permissions to a BlockBackend that becomes read-only, otherwise
things are going to fail.

This requires a bdrv_drain() call because otherwise in-flight AIO
write requests could issue new internal requests while the permission
has already gone away, which would cause assertion failures. Draining
the queue doesn't break AIO requests in any new way, bdrv_reopen() would
drain it anyway only a few lines later.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>

Remove the unnecessary home-grown redefinition of the assert() macro here,
and remove the unusable debug code at the end of the checkpoint() function.
The code there uses assert() with side-effects (assignment to the "mapping"
variable), which should be avoided. Looking more closely, it seems as it is
apparently also only usable for one certain directory layout (with a file
named USB.H in it) and thus is of no use for the rest of the world.
Signed-off-by: NThomas Huth <thuth@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

RestartData is the opaque data of the throttle_group_restart_queue_entry
coroutine. By being stack allocated, it isn't available anymore if
aio_co_enter schedules the coroutine with a bottom half and runs after
throttle_group_restart_queue returns.

Cc: qemu-stable@nongnu.org
Signed-off-by: NManos Pitsidianakis <el13635@mail.ntua.gr>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

If bkt->max == 0 and bkt->burst_length > 1 then we could have a
division by 0 in throttle_do_compute_wait(). That configuration is
however not permitted and is already detected by throttle_is_valid(),
but let's assert it in throttle_compute_wait() to make it explicit.

Found by Coverity (CID: 1381016).
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

So it is easier to copy paste the path.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The default cpu model on s390x does not provide zPCI, which is
not yet wired up on tcg. Moreover, virtio-ccw is the standard
on s390x.

Using virtio-scsi will implicitly pick the right device, so just
switch to that for simplicity.
Signed-off-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The default cpu model on s390x does not provide zPCI, which is
not yet wired up on tcg. Moreover, virtio-ccw is the standard
on s390x, so use the -ccw instead of the -pci versions of virtio
devices on s390x.
Signed-off-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Reviewed-by: NThomas Huth <thuth@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

The default cpu model on s390x does not provide zPCI, which is
not yet wired up on tcg. Moreover, virtio-ccw is the standard
on s390x, so use the -ccw instead of the -pci versions of virtio
devices on s390x.
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NQingFeng Hao <haoqf@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Block driver documentation is available in qemu-doc.html.  It would be
convenient to have documentation for formats, protocols, and filter
drivers in a man page.

Extract the relevant part of qemu-doc.html into a new file called
docs/qemu-block-drivers.texi.  This file can also be built as a
stand-alone document (man, html, etc).
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

People get surprised when, after "qemu-img create -f raw /dev/sdX", they
still see qcow2 with "qemu-img info", if previously the bdev had a qcow2
header. While this is natural because raw doesn't need to write any
magic bytes during creation, hdev_create is free to clear out the first
sector to make sure the stale qcow2 header doesn't cause such confusion.
Signed-off-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

It's not too surprising when a user specifies the backing file relative
to the current working directory instead of the top layer image. This
causes error when they differ. Though the error message has enough
information to infer the fact about the misunderstanding, it is better
if we document this explicitly, so that users don't have to learn from
mistakes.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

A basic set of qemu options is initialised in ./common:

    export QEMU_OPTIONS="-nodefaults -machine accel=qtest"

However, two test cases (172 and 186) overwrite QEMU_OPTIONS and neglect
to manually set '-machine accel=qtest'. Add the missing option for 172.
186 probably only copied the code from 172, it doesn't actually need to
overwrite QEMU_OPTIONS, so remove that in 186.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Tested-by: NCornelia Huck <cohuck@redhat.com>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>

slirp updates

# gpg: Signature made Sun 24 Sep 2017 19:07:51 BST
# gpg:                using RSA key 0x9E511E01C737F075
# gpg: Good signature from "Samuel Thibault <samuel.thibault@aquilenet.fr>"
# gpg:                 aka "Samuel Thibault <sthibault@debian.org>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@gnu.org>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@inria.fr>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@labri.fr>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@ens-lyon.org>"
# gpg:                 aka "Samuel Thibault <samuel.thibault@u-bordeaux.fr>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 900C B024 B679 31D4 0F82  304B D017 8C76 7D06 9EE6
#      Subkey fingerprint: 9A37 3D36 64A8 DC62 DA0A  34FD 9E51 1E01 C737 F075

* remotes/thibault/tags/samuel-thibault:
  slirp: Add a special case for the NULL socket
  slirp: Fix intermittent send queue hangs on a socket
  slirp: Add explanation for hostfwd parsing failure
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

NULL sockets are used for NDP, BOOTP, and other critical operations.
If the topmost mbuf in a NULL session is blocked pending resolution,
it may cause problems if it blocks other packets with a NULL socket.
So do not add mbufs with a NULL socket field to the same session.
Signed-off-by: NKevin Cernekee <cernekee@chromium.org>
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>

if_output() originally sent one mbuf per call and used the slirp->next_m
variable to keep track of where it left off.  But nowadays it tries to
send all of the mbufs from the fastq, and one mbuf from each session on
the batchq.  The next_m variable is both redundant and harmful: there is
a case[0] involving delayed packets in which next_m ends up pointing
to &slirp->if_batchq when an active session still exists, and this
blocks all traffic for that session until qemu is restarted.

The test case was created to reproduce a problem that was seen on
long-running Chromium OS VM tests[1] which rapidly create and
destroy ssh connections through hostfwd.

[0] https://pastebin.com/NNy6LreF
[1] https://bugs.chromium.org/p/chromium/issues/detail?id=766323Signed-off-by: NKevin Cernekee <cernekee@chromium.org>
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>

e.g.
./x86_64-softmmu/qemu-system-x86_64 -nographic -netdev 'user,id=vnet,hostfwd=:555.0.0.0:0-:22'
qemu-system-x86_64: -netdev user,id=vnet,hostfwd=:555.0.0.0:0-:22: Invalid host forwarding rule ':555.0.0.0:0-:22' (Bad host address)
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>

* Speed up AddressSpaceDispatch creation (Alexey)
* Fix kvm.c assert (David)
* Memory fixes and further speedup (me)
* Persistent reservation manager infrastructure (me)
* virtio-serial: add enable_backend callback (Pavel)
* chardev GMainContext fixes (Peter)

# gpg: Signature made Fri 22 Sep 2017 20:07:33 BST
# gpg:                using RSA key 0xBFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (32 commits)
  chardev: remove context in chr_update_read_handler
  chardev: use per-dev context for io_add_watch_poll
  chardev: add Chardev.gcontext field
  chardev: new qemu_chr_be_update_read_handlers()
  scsi: add persistent reservation manager using qemu-pr-helper
  scsi: add multipath support to qemu-pr-helper
  scsi: build qemu-pr-helper
  scsi, file-posix: add support for persistent reservation management
  memory: Share special empty FlatView
  memory: seek FlatView sharing candidates among children subregions
  memory: trace FlatView creation and destruction
  memory: Create FlatView directly
  memory: Get rid of address_space_init_shareable
  memory: Rework "info mtree" to print flat views and dispatch trees
  memory: Do not allocate FlatView in address_space_init
  memory: Share FlatView's and dispatch trees between address spaces
  memory: Move address_space_update_ioeventfds
  memory: Alloc dispatch tree where topology is generared
  memory: Store physical root MR in FlatView
  memory: Rename mem_begin/mem_commit/mem_add helpers
  ...

# Conflicts:
#	configure

We had a per-chardev cache for context, then we don't need this
parameter to be passed in every time when chr_update_read_handler()
called.  As long as we are calling chr_update_read_handler() using
qemu_chr_be_update_read_handlers() we'll be fine.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1505975754-21555-5-git-send-email-peterx@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

It was only passed in by chr_update_read_handlers().  However when
reconnect, we'll lose that context information.  So if a chardev was
running on another context (rather than the default context, the NULL
pointer), it'll switch back to the default context if reconnection
happens.  But, it should really stick to the old context.

Convert all the callers of io_add_watch_poll() to use the internally
cached gcontext.  Then the context should be able to survive even after
reconnections.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1505975754-21555-4-git-send-email-peterx@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

It caches the gcontext that is used to poll the chardev IO.  Before this
patch, we only passed it in via chr_update_read_handlers().  However
that may not be enough if the char backend is disconnected and
reconnected afterward.  There are chardev codes that still assumed the
context be NULL (which is the main context).  Will fix that up in
following up patches.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1505975754-21555-3-git-send-email-peterx@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Add a wrapper for the chr_update_read_handler().
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1505975754-21555-2-git-send-email-peterx@redhat.com>
Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

This adds a concrete subclass of pr-manager that talks to qemu-pr-helper.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Proper support of persistent reservation for multipath devices requires
communication with the multipath daemon, so that the reservation is
registered and applied when a path comes up.  The device mapper
utilities provide a library to do so; this patch makes qemu-pr-helper.c
detect multipath devices and, when one is found, delegate the operation
to libmpathpersist.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Introduce a privileged helper to run persistent reservation commands.
This lets virtual machines send persistent reservations without using
CAP_SYS_RAWIO or out-of-tree patches.  The helper uses Unix permissions
and SCM_RIGHTS to restrict access to processes that can access its socket
and prove that they have an open file descriptor for a raw SCSI device.

The next patch will also correct the usage of persistent reservations
with multipath devices.

It would also be possible to support for Linux's IOC_PR_* ioctls in
the future, to support NVMe devices.  For now, however, only SCSI is
supported.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Python queue, 2017-09-22

* MAINTAINERS update
* Fix logging issue on test scripts using qemu.py

# gpg: Signature made Fri 22 Sep 2017 15:41:43 BST
# gpg:                using RSA key 0x2807936F984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>"
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/python-next-pull-request:
  MAINTAINERS: Add Python scripts
  qemu.py: Call logging.basicConfig() automatically
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Cleber and I are volunteering to review and queue patches for the
Python scripts and modules in scripts/.

I'm setting "M: Odd fixes" because not all scripts are actively
maintained.
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170915230744.22942-1-ehabkost@redhat.com>
[ehabkost: add tests/*.py too]
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

Not all scripts using qemu.py configure the Python logging
module, and end up generating a "No handlers could be found for
logger" message instead of actual log messages.

To avoid requiring every script using qemu.py to configure
logging manually, call basicConfig() when creating a QEMUMachine
object.  This won't affect scripts that already set up logging,
but will ensure that scripts that don't configure logging keep
working.
Reported-by: NKevin Wolf <kwolf@redhat.com>
Fixes: 4738b0a8Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170921162234.847-1-ehabkost@redhat.com>
Reviewed-by: NCleber Rosa <crosa@redhat.com>
Acked-by: NLukáš Doktor <ldoktor@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

migration/next for 20170922

# gpg: Signature made Fri 22 Sep 2017 13:15:06 BST
# gpg:                using RSA key 0xF487EF185872D723
# gpg: Good signature from "Juan Quintela <quintela@redhat.com>"
# gpg:                 aka "Juan Quintela <quintela@trasno.org>"
# Primary key fingerprint: 1899 FF8E DEBF 58CC EE03  4B82 F487 EF18 5872 D723

* remotes/juanquintela/tags/migration/20170922-1:
  migration: split ufd_version_check onto receive/request features part
  migration: fix hardcoded function name in error report
  migration: pass MigrationIncomingState* into migration check functions
  migration: split common postcopy out of ram postcopy
  migration: fix ram_save_pending
  migration: add has_postcopy savevm handler
  bitmap: provide to_le/from_le helpers
  bitmap: introduce bitmap_count_one()
  bitmap: remove BITOP_WORD()
  migration: Split migration_fd_process_incoming
  migration: Create multifd migration threads
  migration: Create x-multifd-page-count parameter
  migration: Create x-multifd-channels parameter
  migration: Add multifd capability
  migration: Create migration_has_all_channels
  migration: Add comments to channel functions
  migration: Teach it about G_SOURCE_REMOVE
  migration: Create migration_ioc_process_incoming()
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Apparently GCC gets bent over comparing enum values against zero.
Replace the conditional with something less readable.
Tested-by: NMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20170921013821.1673-1-jsnow@redhat.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

This modification is necessary for userfault fd features which are
required to be requested from userspace.
UFFD_FEATURE_THREAD_ID is a one of such "on demand" feature, which will
be introduced in the next patch.

QEMU have to use separate userfault file descriptor, due to
userfault context has internal state, and after first call of
ioctl UFFD_API it changes its state to UFFD_STATE_RUNNING (in case of
success), but kernel while handling ioctl UFFD_API expects UFFD_STATE_WAIT_API.
So only one ioctl with UFFD_API is possible per ufd.
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: NAlexey Perevalov <a.perevalov@samsung.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>