This patch allows the user to specify whether to use active or only
background mode for mirror block jobs.  Currently, this setting will
remain constant for the duration of the entire block job.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-14-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

This patch implements active synchronous mirroring.  In active mode, the
passive mechanism will still be in place and is used to copy all
initially dirty clusters off the source disk; but every write request
will write data both to the source and the target disk, so the source
cannot be dirtied faster than data is mirrored to the target.  Also,
once the block job has converged (BLOCK_JOB_READY sent), source and
target are guaranteed to stay in sync (unless an error occurs).

Active mode is completely optional and currently disabled at runtime.  A
later patch will add a way for users to enable it.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-13-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Signed-off-by: NMax Reitz <mreitz@redhat.com>
Message-id: 20180613181823.13618-12-mreitz@redhat.com
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NMax Reitz <mreitz@redhat.com>

This will allow us to access the block job data when the mirror block
driver becomes more complex.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-11-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

This new function allows to look for a consecutively dirty area in a
dirty bitmap.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 20180613181823.13618-10-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Add a function that wraps hbitmap_iter_next() and always calls it in
non-advancing mode first, and in advancing mode next.  The result should
always be the same.

By using this function everywhere we called hbitmap_iter_next() before,
we should get good test coverage for non-advancing hbitmap_iter_next().
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 20180613181823.13618-9-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

This new parameter allows the caller to just query the next dirty
position without moving the iterator.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 20180613181823.13618-8-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Currently, bdrv_replace_node() refuses to create loops from one BDS to
itself if the BDS to be replaced is the backing node of the BDS to
replace it: Say there is a node A and a node B.  Replacing B by A means
making all references to B point to A.  If B is a child of A (i.e. A has
a reference to B), that would mean we would have to make this reference
point to A itself -- so we'd create a loop.

bdrv_replace_node() (through should_update_child()) refuses to do so if
B is the backing node of A.  There is no reason why we should create
loops if B is not the backing node of A, though.  The BDS graph should
never contain loops, so we should always refuse to create them.

If B is a child of A and B is to be replaced by A, we should simply
leave B in place there because it is the most sensible choice.

A more specific argument would be: Putting filter drivers into the BDS
graph is basically the same as appending an overlay to a backing chain.
But the main child BDS of a filter driver is not "backing" but "file",
so restricting the no-loop rule to backing nodes would fail here.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-7-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

With this, the mirror_top_bs is no longer just a technically required
node in the BDS graph but actually represents the block job operation.

Also, drop MirrorBlockJob.source, as we can reach it through
mirror_top_bs->backing.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-6-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

This patch makes the mirror code differentiate between simply waiting
for any operation to complete (mirror_wait_for_free_in_flight_slot())
and specifically waiting for all operations touching a certain range of
the virtual disk to complete (mirror_wait_on_conflicts()).
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-5-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Attach a CoQueue to each in-flight operation so if we need to wait for
any we can use it to wait instead of just blindly yielding and hoping
for some operation to wake us.

A later patch will use this infrastructure to allow requests accessing
the same area of the virtual disk to specifically wait for each other.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-4-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

In order to talk to the source BDS (and maybe in the future to the
target BDS as well) directly, we need to convert our existing AIO
requests into coroutine I/O requests.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-id: 20180613181823.13618-3-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

When converting mirror's I/O to coroutines, we are going to need a point
where these coroutines are created.  mirror_perform() is going to be
that point.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NJeff Cody <jcody@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Message-id: 20180613181823.13618-2-mreitz@redhat.com
Signed-off-by: NMax Reitz <mreitz@redhat.com>

Removing a drive with drive_del while it is being used to run an I/O
intensive workload can cause QEMU to crash.

An AIO flush can yield at some point:

blk_aio_flush_entry()
 blk_co_flush(blk)
  bdrv_co_flush(blk->root->bs)
   ...
    qemu_coroutine_yield()

and let the HMP command to run, free blk->root and give control
back to the AIO flush:

    hmp_drive_del()
     blk_remove_bs()
      bdrv_root_unref_child(blk->root)
       child_bs = blk->root->bs
       bdrv_detach_child(blk->root)
        bdrv_replace_child(blk->root, NULL)
         blk->root->bs = NULL
        g_free(blk->root) <============== blk->root becomes stale
       bdrv_unref(child_bs)
        bdrv_delete(child_bs)
         bdrv_close()
          bdrv_drained_begin()
           bdrv_do_drained_begin()
            bdrv_drain_recurse()
             aio_poll()
              ...
              qemu_coroutine_switch()

and the AIO flush completion ends up dereferencing blk->root:

  blk_aio_complete()
   scsi_aio_complete()
    blk_get_aio_context(blk)
     bs = blk_bs(blk)
 ie, bs = blk->root ? blk->root->bs : NULL
            ^^^^^
            stale

The problem is that we should avoid making block driver graph
changes while we have in-flight requests. Let's drain all I/O
for this BB before calling bdrv_root_unref_child().
Signed-off-by: NGreg Kurz <groug@kaod.org>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This tests both adding and remove a node between bdrv_drain_all_begin()
and bdrv_drain_all_end(), and enabled the existing detach test for
drain_all.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

bdrv_drain_all_*() used bdrv_next() to iterate over all root nodes and
did a subtree drain for each of them. This works fine as long as the
graph is static, but sadly, reality looks different.

If the graph changes so that root nodes are added or removed, we would
have to compensate for this. bdrv_next() returns each root node only
once even if it's the root node for multiple BlockBackends or for a
monitor-owned block driver tree, which would only complicate things.

The much easier and more obviously correct way is to fundamentally
change the way the functions work: Iterate over all BlockDriverStates,
no matter who owns them, and drain them individually. Compensation is
only necessary when a new BDS is created inside a drain_all section.
Removal of a BDS doesn't require any action because it's gone afterwards
anyway.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

In the future, bdrv_drained_all_begin/end() will drain all invidiual
nodes separately rather than whole subtrees. This means that we don't
want to propagate the drain to all parents any more: If the parent is a
BDS, it will already be drained separately. Recursing to all parents is
unnecessary work and would make it an O(n²) operation.

Prepare the drain function for the changed drain_all by adding an
ignore_bds_parents parameter to the internal implementation that
prevents the propagation of the drain to BDS parents. We still (have to)
propagate it to non-BDS parents like BlockBackends or Jobs because those
are not drained separately.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Before we can introduce a single polling loop for all nodes in
bdrv_drain_all_begin(), we must make sure to run it outside of coroutine
context like we already do for bdrv_do_drained_begin().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

bdrv_drain_all() wants to have a single polling loop for draining the
in-flight requests of all nodes. This means that the AIO_WAIT_WHILE()
condition relies on activity in multiple AioContexts, which is polled
from the mainloop context. We must therefore call AIO_WAIT_WHILE() from
the mainloop thread and use the AioWait notification mechanism.

Just randomly picking the AioContext of any non-mainloop thread would
work, but instead of bothering to find such a context in the caller, we
can just as well accept NULL for ctx.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This adds a test case that goes wrong if bdrv_drain_invoke() calls
aio_poll().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

We cannot allow aio_poll() in bdrv_drain_invoke(begin=true) until we're
done with propagating the drain through the graph and are doing the
single final BDRV_POLL_WHILE().

Just schedule the coroutine with the callback and increase bs->in_flight
to make sure that the polling phase will wait for it.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Signed-off-by: NKevin Wolf <kwolf@redhat.com>

bdrv_do_drained_begin() is only safe if we have a single
BDRV_POLL_WHILE() after quiescing all affected nodes. We cannot allow
that parent callbacks introduce a nested polling loop that could cause
graph changes while we're traversing the graph.

Split off bdrv_do_drained_begin_quiesce(), which only quiesces a single
node without waiting for its requests to complete. These requests will
be waited for in the BDRV_POLL_WHILE() call down the call chain.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

If bdrv_do_drained_begin() polls during its subtree recursion, the graph
can change and mess up the bs->children iteration. Test that this
doesn't happen.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Anything can happen inside BDRV_POLL_WHILE(), including graph
changes that may interfere with its callers (e.g. child list iteration
in recursive callers of bdrv_do_drained_begin).

Switch to a single BDRV_POLL_WHILE() call for the whole subtree at the
end of bdrv_do_drained_begin() to avoid such effects. The recursion
happens now inside the loop condition. As the graph can only change
between bdrv_drain_poll() calls, but not inside of it, doing the
recursion here is safe.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

This patch adds two bdrv-drain tests for what happens if some BDS goes
away during the drainage.

The basic idea is that you have a parent BDS with some child nodes.
Then, you drain one of the children.  Because of that, the party who
actually owns the parent decides to (A) delete it, or (B) detach all its
children from it -- both while the child is still being drained.

A real-world case where this can happen is the mirror block job, which
may exit if you drain one of its children.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

For bdrv_drain(), recursively waiting for child node requests is
pointless because we didn't quiesce their parents, so new requests could
come in anyway. Letting the function work only on a single node makes it
more consistent.

For subtree drains and drain_all, we already have the recursion in
bdrv_do_drained_begin(), so the extra recursion doesn't add anything
either.

Remove the useless code.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

We already requested that block jobs be paused in .bdrv_drained_begin,
but no guarantee was made that the job was actually inactive at the
point where bdrv_drained_begin() returned.

This introduces a new callback BdrvChildRole.bdrv_drained_poll() and
uses it to make bdrv_drain_poll() consider block jobs using the node to
be drained.

For the test case to work as expected, we have to switch from
block_job_sleep_ns() to qemu_co_sleep_ns() so that the test job is even
considered active and must be waited for when draining the node.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Commit 91af091f added an additional aio_poll() to BDRV_POLL_WHILE()
in order to make sure that all pending BHs are executed on drain. This
was the wrong place to make the fix, as it is useless overhead for all
other users of the macro and unnecessarily complicates the mechanism.

This patch effectively reverts said commit (the context has changed a
bit and the code has moved to AIO_WAIT_WHILE()) and instead polls in the
loop condition for drain.

The effect is probably hard to measure in any real-world use case
because actual I/O will dominate, but if I run only the initialisation
part of 'qemu-img convert' where it calls bdrv_block_status() for the
whole image to find out how much data there is copy, this phase actually
needs only roughly half the time after this patch.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

Since we use bdrv_do_drained_begin/end() for bdrv_drain_all_begin/end(),
coroutine context is automatically left with a BH, preventing the
deadlocks that made bdrv_drain_all*() unsafe in coroutine context. Now
that we even removed the old polling code as dead code, it's obvious
that it's compatible now.

Enable the coroutine test cases for bdrv_drain_all().
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

All involved nodes are already idle, we called bdrv_do_drain_begin() on
them.

The comment in the code suggested that this was not correct because the
completion of a request on one node could spawn a new request on a
different node (which might have been drained before, so we wouldn't
drain the new request). In reality, new requests to different nodes
aren't spawned out of nothing, but only in the context of a parent
request, and they aren't submitted to random nodes, but only to child
nodes. As long as we still poll for the completion of the parent request
(which we do), draining each root node separately is good enough.

Remove the additional polling code from bdrv_drain_all_begin() and
replace it with an assertion that all nodes are already idle after we
drained them separately.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

All callers pass false for the 'recursive' parameter now. Remove it.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

bdrv_do_drain_begin/end() implement already everything that
bdrv_drain_all_begin/end() need and currently still do manually: Disable
external events, call parent drain callbacks, call block driver
callbacks.

It also does two more things:

The first is incrementing bs->quiesce_counter. bdrv_drain_all() already
stood out in the test case by behaving different from the other drain
variants. Adding this is not only safe, but in fact a bug fix.

The second is calling bdrv_drain_recurse(). We already do that later in
the same function in a loop, so basically doing an early first iteration
doesn't hurt.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

As long as nobody keeps the other I/O thread from working, there is no
reason why bdrv_drain() wouldn't work with cross-AioContext events. The
key is that the root request we're waiting for is in the AioContext
we're polling (which it always is for bdrv_drain()) so that aio_poll()
is woken up in the end.

Add a test case that shows that it works. Remove the comment in
bdrv_drain() that claims otherwise.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

Migration pull 2018-06-15

# gpg: Signature made Fri 15 Jun 2018 16:13:17 BST
# gpg:                using RSA key 0516331EBC5BFDE7
# gpg: Good signature from "Dr. David Alan Gilbert (RH2) <dgilbert@redhat.com>"
# Primary key fingerprint: 45F5 C71B 4A0C B7FB 977A  9FA9 0516 331E BC5B FDE7

* remotes/dgilbert/tags/pull-migration-20180615a:
  migration: calculate expected_downtime with ram_bytes_remaining()
  migration/postcopy: Wake rate limit sleep on postcopy request
  migration: Wake rate limiting for urgent requests
  migration/postcopy: Add max-postcopy-bandwidth parameter
  migration: introduce migration_update_rates
  migration: fix counting xbzrle cache_miss_rate
  migration/block-dirty-bitmap: fix dirty_bitmap_load
  migration: Poison ramblock loops in migration
  migration: Fixes for non-migratable RAMBlocks
  typedefs: add QJSON
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/edgar/tags/edgar/xilinx-next-2018-06-15.for-upstream' into staging

xilinx-next-2018-06-15.for-upstream

# gpg: Signature made Fri 15 Jun 2018 15:32:47 BST
# gpg:                using RSA key 29C596780F6BCA83
# gpg: Good signature from "Edgar E. Iglesias (Xilinx key) <edgar.iglesias@xilinx.com>"
# gpg:                 aka "Edgar E. Iglesias <edgar.iglesias@gmail.com>"
# Primary key fingerprint: AC44 FEDC 14F7 F1EB EDBF  4151 29C5 9678 0F6B CA83

* remotes/edgar/tags/edgar/xilinx-next-2018-06-15.for-upstream:
  target-microblaze: Rework NOP/zero instruction handling
  target-microblaze: mmu: Correct masking of output addresses
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Block layer patches:

- Fix options that work only with -drive or -blockdev, but not with
  both, because of QDict type confusion
- rbd: Add options 'auth-client-required' and 'key-secret'
- Remove deprecated -drive options serial/addr/cyls/heads/secs/trans
- rbd, iscsi: Remove deprecated 'filename' option
- Fix 'qemu-img map' crash with unaligned image size
- Improve QMP documentation for jobs

# gpg: Signature made Fri 15 Jun 2018 15:20:03 BST
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream: (26 commits)
  block: Remove dead deprecation warning code
  block: Remove deprecated -drive option serial
  block: Remove deprecated -drive option addr
  block: Remove deprecated -drive geometry options
  rbd: New parameter key-secret
  rbd: New parameter auth-client-required
  block: Fix -blockdev / blockdev-add for empty objects and arrays
  check-block-qdict: Cover flattening of empty lists and dictionaries
  check-block-qdict: Rename qdict_flatten()'s variables for clarity
  block-qdict: Simplify qdict_is_list() some
  block-qdict: Clean up qdict_crumple() a bit
  block-qdict: Tweak qdict_flatten_qdict(), qdict_flatten_qlist()
  block-qdict: Simplify qdict_flatten_qdict()
  block: Make remaining uses of qobject input visitor more robust
  block: Factor out qobject_input_visitor_new_flat_confused()
  block: Clean up a misuse of qobject_to() in .bdrv_co_create_opts()
  block: Fix -drive for certain non-string scalars
  block: Fix -blockdev for certain non-string scalars
  qobject: Move block-specific qdict code to block-qdict.c
  block: Add block-specific QDict header
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target-arm and miscellaneous queue:
 * fix KVM state save/restore for GICv3 priority registers for high IRQ numbers
 * hw/arm/mps2-tz: Put ethernet controller behind PPC
 * hw/sh/sh7750: Convert away from old_mmio
 * hw/m68k/mcf5206: Convert away from old_mmio
 * hw/block/pflash_cfi02: Convert away from old_mmio
 * hw/watchdog/wdt_i6300esb: Convert away from old_mmio
 * hw/input/pckbd: Convert away from old_mmio
 * hw/char/parallel: Convert away from old_mmio
 * armv7m: refactor to get rid of armv7m_init() function
 * arm: Don't crash if user tries to use a Cortex-M CPU without an NVIC
 * hw/core/or-irq: Support more than 16 inputs to an OR gate
 * cpu-defs.h: Document CPUIOTLBEntry 'addr' field
 * cputlb: Pass cpu_transaction_failed() the correct physaddr
 * CODING_STYLE: Define our preferred form for multiline comments
 * Add and use new stn_*_p() and ldn_*_p() memory access functions
 * target/arm: More parts of the upcoming SVE support
 * aspeed_scu: Implement RNG register
 * m25p80: add support for two bytes WRSR for Macronix chips
 * exec.c: Handle IOMMUs being in the path of TCG CPU memory accesses
 * target/arm: Allow ARMv6-M Thumb2 instructions

# gpg: Signature made Fri 15 Jun 2018 15:24:03 BST
# gpg:                using RSA key 3C2525ED14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20180615: (43 commits)
  target/arm: Allow ARMv6-M Thumb2 instructions
  exec.c: Handle IOMMUs in address_space_translate_for_iotlb()
  iommu: Add IOMMU index argument to translate method
  iommu: Add IOMMU index argument to notifier APIs
  iommu: Add IOMMU index concept to IOMMU API
  m25p80: add support for two bytes WRSR for Macronix chips
  aspeed_scu: Implement RNG register
  target/arm: Implement SVE Floating Point Arithmetic - Unpredicated Group
  target/arm: Implement SVE Integer Wide Immediate - Unpredicated Group
  target/arm: Implement FDUP/DUP
  target/arm: Implement SVE Integer Compare - Scalars Group
  target/arm: Implement SVE Predicate Count Group
  target/arm: Implement SVE Partition Break Group
  target/arm: Implement SVE Integer Compare - Immediate Group
  target/arm: Implement SVE Integer Compare - Vectors Group
  target/arm: Implement SVE Select Vectors Group
  target/arm: Implement SVE vector splice (predicated)
  target/arm: Implement SVE reverse within elements
  target/arm: Implement SVE copy to vector (predicated)
  target/arm: Implement SVE conditionally broadcast/extract element
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

ARMv6-M supports 6 Thumb2 instructions. This patch checks for these
instructions and allows their execution.
Like Thumb2 cores, ARMv6-M always interprets BL instruction as 32-bit.

This patch is required for future Cortex-M0 support.
Signed-off-by: NJulia Suvorova <jusual@mail.ru>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Message-id: 20180612204632.28780-1-jusual@mail.ru
[PMM: move armv6m_insn[] and armv6m_mask[] closer to
 point of use, and mark 'const'. Check for M-and-not-v7
 rather than M-and-6.]
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

Currently we don't support board configurations that put an IOMMU
in the path of the CPU's memory transactions, and instead just
assert() if the memory region fonud in address_space_translate_for_iotlb()
is an IOMMUMemoryRegion.

Remove this limitation by having the function handle IOMMUs.
This is mostly straightforward, but we must make sure we have
a notifier registered for every IOMMU that a transaction has
passed through, so that we can flush the TLB appropriately
when any of the IOMMUs change their mappings.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Message-id: 20180604152941.20374-5-peter.maydell@linaro.org