In commit 63f0f45f the following
mechanical change was made:

         if (!state) {
-            qemu_aio_wait();
+            aio_poll(state->s->aio_context, true);
         }

The new code now checks if state is NULL and then dereferences it
('state->s') which is obviously incorrect.

This commit replaces state->s->aio_context with
bdrv_get_aio_context(bs), fixing this problem.  The two other hunks
are concerned with getting the BlockDriverState pointer bs to where it
is needed.

The original bug causes a segfault when using libguestfs to access a
VMware vCenter Server and doing any kind of complex read-heavy
operations.  With this commit the segfault goes away.
Signed-off-by: NRichard W.M. Jones <rjones@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NBenoît Canet <benoit.canet@nodalink.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

In order to access VMware ESX efficiently, we need to send a session
cookie.  This patch is very simple and just allows you to send that
session cookie.  It punts on the question of how you get the session
cookie in the first place, but in practice you can just run a `curl'
command against the server and extract the cookie that way.

To use it, add file.cookie to the curl URL.  For example:

$ qemu-img info 'json: {
    "file.driver":"https",
    "file.url":"https://vcenter/folder/Windows%202003/Windows%202003-flat.vmdk?dcPath=Datacenter&dsName=datastore1",
    "file.sslverify":"off",
    "file.cookie":"vmware_soap_session=\"52a01262-bf93-ccce-d379-8dabb3e55560\""}'
image: [...]
file format: raw
virtual size: 8.0G (8589934592 bytes)
disk size: unavailable
Signed-off-by: NRichard W.M. Jones <rjones@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Now that drive_del acquires the AioContext we can safely allow deleting
the drive.  As with non-dataplane mode, all I/Os submitted by the guest
after drive_del will return EIO.

This patch makes hot unplug work with virtio-blk dataplane.  Previously
drive_del reported an error because the device was busy.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Make drive_del safe for dataplane where another thread may be running
the BlockDriverState's AioContext.

Note the assumption that AioContext's lifetime exceeds DriveInfo and
BlockDriverState.  We release AioContext after DriveInfo and
BlockDriverState are potentially freed.

This is clearly safe with the global AioContext but also with -object
iothread and implicit iothreads created by -device
virtio-blk-pci,x-data-plane=on (their lifetime is tied to DeviceState,
not BlockDriverState).
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

If two Linux AIO request completions are fetched in the same
io_getevents() call, QEMU will deadlock if request A's callback waits
for request B to complete using an aio_poll() loop.  This was reported
to happen with the mirror blockjob.

This patch moves completion processing into a BH and makes it resumable.
Nested event loops can resume completion processing so that request B
will complete and the deadlock will not occur.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Marcin Gibuła <m.gibula@beyond.pl>
Reported-by: NMarcin Gibuła <m.gibula@beyond.pl>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Tested-by: NMarcin Gibuła <m.gibula@beyond.pl>

This test case covers the basic bdrv_aio_multiwrite() scenarios:
1. Single request
2. Sequential requests (AABB)
3. Superset overlapping requests (AABBAA)
4. Subset overlapping requests (BBAABB)
5. Head overlapping requests (AABB)
6. Tail overlapping requests (BBAA)
7. Disjoint requests (AA BB)
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

When request A is a strict superset of request B:

  AAAAAAAA
    BBBB

multiwrite_merge() merges them as follows:

  AABBBB

The tail of request A should have been included:

  AABBBBAA

This patch fixes data loss but this code path is probably rare.  Since
guests cannot assume ordering between in-flight requests, few
applications submit overlapping write requests.
Reported-by: NSlava Pestov <sviatoslav.pestov@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>

Keep the NBD server always in the same AIO context as the exported BDS
by calling bdrv_add_aio_context_notifier() and implementing the required
callbacks.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

If a long-running operation on a BDS wants to always remain in the same
AIO context, it somehow needs to keep track of the BDS changing its
context. This adds a function for registering callbacks on a BDS which
are called whenever the BDS is attached or detached from an AIO context.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

There is no variant of aio_set_fd_handler() like qemu_set_fd_handler2(),
so we cannot give a can_read() callback function. Instead, unregister
the nbd_read() function whenever we cannot read and re-register it as
soon as we can read again.

All this is hidden behind the functions nbd_set_handlers() (which
registers all handlers for the AIO context and file descriptor belonging
to the given client), nbd_unset_handlers() (which unregisters them) and
nbd_update_can_read() (which checks whether NBD can read for the given
client and acts accordingly).
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

We should reinit local_err as NULL inside the while loop or g_free() will report
corrupption and abort the QEMU when sheepdog driver tries reconnecting.

This was broken in commit 356b4ca2.

qemu-system-x86_64: failed to get the header, Resource temporarily unavailable
qemu-system-x86_64: Failed to connect to socket: Connection refused
qemu-system-x86_64: (null)
[xcb] Unknown sequence number while awaiting reply
[xcb] Most likely this is a multi-threaded client and XInitThreads has not been called
[xcb] Aborting, sorry about that.
qemu-system-x86_64: ../../src/xcb_io.c:298: poll_for_response: Assertion `!xcb_xlib_threads_sequence_lost' failed.
Aborted (core dumped)

Cc: qemu-devel@nongnu.org
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NLiu Yuan <namei.unix@gmail.com>
Reviewed-by: NBenoît Canet <benoit.canet@nodalink.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Uses the same select/WSAEventSelect scheme as main-loop.c.
WSAEventSelect() is edge-triggered, so it cannot be used
directly, but it is still used as a way to exit from a
blocking g_poll().

Before g_poll() is called, we poll sockets with a non-blocking
select() to achieve the level-triggered semantics we require:
if a socket is ready, the g_poll() is made non-blocking too.

Based on a patch from Or Goshen.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This will be used to implement socket polling on Windows.
On Windows, select() and g_poll() are completely different;
sockets are polled with select() before calling g_poll,
and the g_poll must be nonblocking if select() says a
socket is ready.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Use EventNotifier instead of a pipe, which makes it trivial to test
timers on Windows.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

So far, aio_poll's scheme was dispatch/poll/dispatch, where
the first dispatch phase was used only in the GSource case in
order to avoid a blocking poll.  Earlier patches changed it to
dispatch/prepare/poll/dispatch, where prepare is aio_compute_timeout.

By making aio_dispatch public, we can remove the first dispatch
phase altogether, so that both aio_poll and the GSource use the same
prepare/poll/dispatch scheme.

This patch breaks the invariant that aio_poll(..., true) will not block
the first time it returns false.  This used to be fundamental for
qemu_aio_flush's implementation as "while (qemu_aio_wait()) {}" but
no code in QEMU relies on this invariant anymore.  The return value
of aio_poll() is now comparable with that of g_main_context_iteration.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Make the dispatching phase the same before blocking and afterwards.
The next patch will make aio_dispatch public and use it directly
for the GSource case, instead of aio_poll.  aio_poll can then be
simplified heavily.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Later, the call to aio_dispatch will move int the GSource wrapper, while the
standalone case will still be call the component functions aio_bh_poll,
aio_dispatch_handlers and timerlistgroup_run_timers.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This is similar to what aio_poll does in the stand-alone case.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Right now, QEMU invokes aio_bh_poll before the "poll" phase
of aio_poll.  It is simpler to do it afterwards and skip the
"poll" phase altogether when the OS-dependent parts of AioContext
are invoked from GSource.  This way, AioContext behaves more
similarly when used as a GSource vs. when used as stand-alone.

As a start, take bottom halves into account when computing the
poll timeout.  If a bottom half is ready, do a non-blocking
poll.  As a side effect, this makes idle bottom halves work
with aio_poll; an improvement, but not really an important
one since they are deprecated.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Name the 'granularity' parameter and give its expected value range.
Previously the device name was mistakenly reported as the parameter
name.

Note that the error class is unchanged from ERROR_CLASS_GENERIC_ERROR.
Reported-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NBenoît Canet <benoit.canet@nodalink.com>

block_job_sleep_ns is the only user. Since we are moving towards
AioContext aware code, it's better to use the explicit version and drop
the old one.
Signed-off-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NBenoît Canet <benoit.canet@nodalink.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

This patch adds single read pattern to quorum driver and quorum vote is default
pattern.

For now we do a quorum vote on all the reads, it is designed for unreliable
underlying storage such as non-redundant NFS to make sure data integrity at the
cost of the read performance.

For some use cases as following:

        VM
  --------------
  |            |
  v            v
  A            B

Both A and B has hardware raid storage to justify the data integrity on its own.
So it would help performance if we do a single read instead of on all the nodes.
Further, if we run VM on either of the storage node, we can make a local read
request for better performance.

This patch generalize the above 2 nodes case in the N nodes. That is,

vm -> write to all the N nodes, read just one of them. If single read fails, we
try to read next node in FIFO order specified by the startup command.

The 2 nodes case is very similar to DRBD[1] though lack of auto-sync
functionality in the single device/node failure for now. But compared with DRBD
we still have some advantages over it:

- Suppose we have 20 VMs running on one(assume A) of 2 nodes' DRBD backed
storage. And if A crashes, we need to restart all the VMs on node B. But for
practice case, we can't because B might not have enough resources to setup 20 VMs
at once. So if we run our 20 VMs with quorum driver, and scatter the replicated
images over the data center, we can very likely restart 20 VMs without any
resource problem.

After all, I think we can build a more powerful replicated image functionality
on quorum and block jobs(block mirror) to meet various High Availibility needs.

E.g, Enable single read pattern on 2 children,

-drive driver=quorum,children.0.file.filename=0.qcow2,\
children.1.file.filename=1.qcow2,read-pattern=fifo,vote-threshold=1

[1] http://en.wikipedia.org/wiki/Distributed_Replicated_Block_Device

[Dropped \n from an error_setg() error message
--Stefan]

Cc: Benoit Canet <benoit@irqsave.net>
Cc: Eric Blake <eblake@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NLiu Yuan <namei.unix@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Cc: Eric Blake <eblake@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NBenoît Canet <benoit.canet@nodalink.com>
Signed-off-by: NLiu Yuan <namei.unix@gmail.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

Recently, sheepdog revived its VDI locking functionality. This patch
updates sheepdog driver of QEMU for this feature. It changes an error
code for a case of failed locking. -EBUSY is a suitable one.
Reported-by: NValerio Pachera <sirio81@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Liu Yuan <namei.unix@gmail.com>
Cc: MORITA Kazutaka <morita.kazutaka@gmail.com>
Signed-off-by: NHitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The update is required for supporting iSCSI multipath. It doesn't
affect behavior of QEMU driver but adding a new field to vdi request
struct is required.

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Liu Yuan <namei.unix@gmail.com>
Cc: MORITA Kazutaka <morita.kazutaka@gmail.com>
Signed-off-by: NHitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

The out label has the qemu_progress_end() and other cleanup calls.
Always goto out in error paths so the cleanup happens.  These error
paths now return 1 instead of -1.

Note that bdrv_unref(NULL) is safe.  We just need to initialize bs to
NULL at the top of the function.

We can now remove the obsolete bs_old_backing = NULL and bs_new_backing
= NULL for safe mode.  Originally it was necessary in commit 3e85c6fd
("qemu-img rebase") but became useless in commit c2abccec ("qemu-img:
avoid calling exit(1) to release resources properly") because the
variables are already initialized during declaration.
Reported-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

If img_compare() fails to parse the cache flags the goto out3 code path
will call qemu_progress_end().  Make sure we actually call
qemu_progress_init() first.
Reported-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

The img_commit() return value is a process exit code.  Use 1 for failure
instead of -1.  The other failure paths in this function already use 1.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NMax Reitz <mreitz@redhat.com>

The curl hardcoded timeout (5 seconds) sometimes is not long
enough depending on the remote server configuration and network
traffic. The user should be able to set how much long he is
willing to wait for the connection.

Adding a new option to set this timeout gives the user this
flexibility. The previous default timeout of 5 seconds will be
used if this option is not present.
Reviewed-by: NFam Zheng <famz@redhat.com>
Signed-off-by: NDaniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Reviewed-by: NBenoit Canet <benoit.canet@nodalink.com>
Tested-by: NRichard W.M. Jones <rjones@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

We identify devices by their Open Firmware device paths.  The encoding
of bus numbers is incorrect: idebus_get_fw_dev_path() formats them in
decimal, while SeaBIOS uses hexadecimal.  With bus number > 9, SeaBIOS
will miss the bootindex (lucky case), or apply it to another device
(unlucky case).

Bug can't bite right now: ich9-ahci has six ports, and the sysbus-ahci
created by Calxeda Highbank has just one.

Fix it anyway, by changing %d to %x.

I couldn't find an Open Firmware spec covering this.  For what it's
worth, OVMF agrees with SeaBIOS.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

SCSI patches include bug fixes from Fam and Peter, improved error
reporting from Fam and a fix for DPRINTF bitrot.  Memory patches try
again to initialize name from the QOM name.

# gpg: Signature made Thu 28 Aug 2014 15:10:31 BST using RSA key ID 9B4D86F2
# gpg: Good signature from "Paolo Bonzini <pbonzini@redhat.com>"
# gpg:                 aka "Paolo Bonzini <bonzini@gnu.org>"

* remotes/bonzini/tags/for-upstream:
  memory: Lazy init name from QOM name as needed
  xen: hvm: Abstract away memory region name ref
  xen-hvm: Constify string
  virtio-scsi: Report error if num_queues is 0 or too large
  scsi-generic: remove superfluous DPRINTF avoid to break compiling
  block/iscsi: fix memory corruption on iscsi resize
  scsi-bus: Convert DeviceClass init to realize
  block: Pass errp in blkconf_geometry
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Mostly bugfixes + Alexey's interface-based implementation
of the NMI monitor command.

# gpg: Signature made Thu 28 Aug 2014 15:07:22 BST using RSA key ID 9B4D86F2
# gpg: Good signature from "Paolo Bonzini <pbonzini@redhat.com>"
# gpg:                 aka "Paolo Bonzini <bonzini@gnu.org>"

* remotes/kvm/tags/for-upstream:
  mc146818rtc: reinitialize irq_reinject_on_ack_count on reset
  target-i386: Add "tsc_adjust" CPU feature name
  target-i386: Add "mpx" CPU feature name
  vl: process -object after other backend options
  checkpatch.pl: adjust typedef definition to QEMU coding style
  x86: Clear MTRRs on vCPU reset
  x86: kvm: Add MTRR support for kvm_get|put_msrs()
  x86: Use common variable range MTRR counts
  target-i386: Don't forbid NX bit on PAE PDEs and PTEs
  spapr: Add support for new NMI interface
  s390x: Migrate to new NMI interface
  s390x: Convert QEMUMachine to MachineClass
  cpus: Define callback for QEMU "nmi" command
  kvm: run cpu state synchronization on target vcpu thread
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

To support name retrieval of MemoryRegions that were created
dynamically (that is, not via memory_region_init and friends). We
cache the name in MemoryRegion's state as
object_get_canonical_path_component mallocs the returned value
so it's not suitable for direct return to callers. Memory already
frees the name field, so this will be garbage collected along with
the MR object.
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

The mr->name field is removed. This slipped through compile testing.
Fix.
Reviewed-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

It's constant, and sourced from existing const strings. Avoid dodgy
casts by converting to const.
Signed-off-by: NPeter Crosthwaite <peter.crosthwaite@xilinx.com>
Reviewed-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

Merge remote-tracking branch 'remotes/stefanha/tags/fix-buildbot-12082014-pull-request' into staging

Pull request

# gpg: Signature made Thu 28 Aug 2014 13:43:00 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/fix-buildbot-12082014-pull-request:
  Revert "qemu-img: sort block formats in help message"
  block: sort formats alphabetically in bdrv_iterate_format()
  mirror: fix uninitialized variable delay_ns warnings
  trace: avoid Python 2.5 all() in tracetool
  libqtest: launch QEMU with QEMU_AUDIO_DRV=none
  qapi.py: avoid Python 2.5+ any() function
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

This reverts commit 1a443c1b and the
later commit 395071a7.

GSequence was introduced in glib 2.14.  RHEL 5 fails to compile since it
uses glib 2.12.3.

Now that bdrv_iterate_format() invokes the iteration callback in sorted
order these commits are unnecessary.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NBenoît Canet <benoit.canet@nodalink.com>

Format names are best consumed in alphabetical order.  This makes
human-readable output easy to produce.

bdrv_iterate_format() already has an array of format strings.  Sort them
before invoking the iteration callback.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NBenoît Canet <benoit.canet@nodalink.com>