When the reconnect in NBD client is in progress, the iochannel used for
NBD connection doesn't exist.  Therefore an attempt to detach it from
the aio_context of the parent BlockDriverState results in a NULL pointer
dereference.

The problem is triggerable, in particular, when an outgoing migration is
about to finish, and stopping the dataplane tries to move the
BlockDriverState from the iothread aio_context to the main loop.  If the
NBD connection is lost before this point, and the NBD client has entered
the reconnect procedure, QEMU crashes:

  #0  qemu_aio_coroutine_enter (ctx=0x5618056c7580, co=0x0)
      at /build/qemu-6MF7tq/qemu-5.0.1/util/qemu-coroutine.c:109
  #1  0x00005618034b1b68 in nbd_client_attach_aio_context_bh (
      opaque=0x561805ed4c00) at /build/qemu-6MF7tq/qemu-5.0.1/block/nbd.c:164
  #2  0x000056180353116b in aio_wait_bh (opaque=0x7f60e1e63700)
      at /build/qemu-6MF7tq/qemu-5.0.1/util/aio-wait.c:55
  #3  0x0000561803530633 in aio_bh_call (bh=0x7f60d40a7e80)
      at /build/qemu-6MF7tq/qemu-5.0.1/util/async.c:136
  #4  aio_bh_poll (ctx=ctx@entry=0x5618056c7580)
      at /build/qemu-6MF7tq/qemu-5.0.1/util/async.c:164
  #5  0x0000561803533e5a in aio_poll (ctx=ctx@entry=0x5618056c7580,
      blocking=blocking@entry=true)
      at /build/qemu-6MF7tq/qemu-5.0.1/util/aio-posix.c:650
  #6  0x000056180353128d in aio_wait_bh_oneshot (ctx=0x5618056c7580,
      cb=<optimized out>, opaque=<optimized out>)
      at /build/qemu-6MF7tq/qemu-5.0.1/util/aio-wait.c:71
  #7  0x000056180345c50a in bdrv_attach_aio_context (new_context=0x5618056c7580,
      bs=0x561805ed4c00) at /build/qemu-6MF7tq/qemu-5.0.1/block.c:6172
  #8  bdrv_set_aio_context_ignore (bs=bs@entry=0x561805ed4c00,
      new_context=new_context@entry=0x5618056c7580,
      ignore=ignore@entry=0x7f60e1e63780)
      at /build/qemu-6MF7tq/qemu-5.0.1/block.c:6237
  #9  0x000056180345c969 in bdrv_child_try_set_aio_context (
      bs=bs@entry=0x561805ed4c00, ctx=0x5618056c7580,
      ignore_child=<optimized out>, errp=<optimized out>)
      at /build/qemu-6MF7tq/qemu-5.0.1/block.c:6332
  #10 0x00005618034957db in blk_do_set_aio_context (blk=0x56180695b3f0,
      new_context=0x5618056c7580, update_root_node=update_root_node@entry=true,
      errp=errp@entry=0x0)
      at /build/qemu-6MF7tq/qemu-5.0.1/block/block-backend.c:1989
  #11 0x00005618034980bd in blk_set_aio_context (blk=<optimized out>,
      new_context=<optimized out>, errp=errp@entry=0x0)
      at /build/qemu-6MF7tq/qemu-5.0.1/block/block-backend.c:2010
  #12 0x0000561803197953 in virtio_blk_data_plane_stop (vdev=<optimized out>)
      at /build/qemu-6MF7tq/qemu-5.0.1/hw/block/dataplane/virtio-blk.c:292
  #13 0x00005618033d67bf in virtio_bus_stop_ioeventfd (bus=0x5618056d9f08)
      at /build/qemu-6MF7tq/qemu-5.0.1/hw/virtio/virtio-bus.c:245
  #14 0x00005618031c9b2e in virtio_vmstate_change (opaque=0x5618056d9f90,
      running=0, state=<optimized out>)
      at /build/qemu-6MF7tq/qemu-5.0.1/hw/virtio/virtio.c:3220
  #15 0x0000561803208bfd in vm_state_notify (running=running@entry=0,
      state=state@entry=RUN_STATE_FINISH_MIGRATE)
      at /build/qemu-6MF7tq/qemu-5.0.1/softmmu/vl.c:1275
  #16 0x0000561803155c02 in do_vm_stop (state=RUN_STATE_FINISH_MIGRATE,
      send_stop=<optimized out>) at /build/qemu-6MF7tq/qemu-5.0.1/cpus.c:1032
  #17 0x00005618033e3765 in migration_completion (s=0x5618056e6960)
      at /build/qemu-6MF7tq/qemu-5.0.1/migration/migration.c:2914
  #18 migration_iteration_run (s=0x5618056e6960)
      at /build/qemu-6MF7tq/qemu-5.0.1/migration/migration.c:3275
  #19 migration_thread (opaque=opaque@entry=0x5618056e6960)
      at /build/qemu-6MF7tq/qemu-5.0.1/migration/migration.c:3439
  #20 0x0000561803536ad6 in qemu_thread_start (args=<optimized out>)
      at /build/qemu-6MF7tq/qemu-5.0.1/util/qemu-thread-posix.c:519
  #21 0x00007f61085d06ba in start_thread ()
     from /lib/x86_64-linux-gnu/libpthread.so.0
  #22 0x00007f610830641d in sysctl () from /lib/x86_64-linux-gnu/libc.so.6
  #23 0x0000000000000000 in ?? ()

Fix it by checking that the iochannel is non-null before trying to
detach it from the aio_context.  If it is null, no detaching is needed,
and it will get reattached in the proper aio_context once the connection
is reestablished.

Signed-off-by: Roman Kagan <rvkagan@yandex-team.ru>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210129073859.683063-2-rvkagan@yandex-team.ru>
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert now copy_range parameters which are already 64bit to signed
type.

It's safe as we don't work with requests overflowing BDRV_MAX_LENGTH
(which is less than INT64_MAX), and do check the requests in
bdrv_co_copy_range_internal() (by bdrv_check_request32(), which calls
bdrv_check_request()).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-17-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

Now, since bdrv_co_preadv_part() and bdrv_co_pwritev_part() have been
updated, update all their wrappers.

For all of them type of 'bytes' is widening, so callers are safe. We
have update request_fn in blkverify.c simultaneously. Still it's just a
pointer to one of bdrv_co_pwritev() or bdrv_co_preadv(), and type is
widening for callers of the request_fn anyway.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-16-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, prepare bdrv_co_preadv_part() and bdrv_co_pwritev_part() and their
remaining dependencies now.

bdrv_pad_request() is updated simultaneously, as pointer to bytes passed
to it both from bdrv_co_pwritev_part() and bdrv_co_preadv_part().

So, all callers of bdrv_pad_request() are updated to pass 64bit bytes.
bdrv_pad_request() is already good for 64bit requests, add
corresponding assertion.

Look at bdrv_co_preadv_part() and bdrv_co_pwritev_part().
Type is widening, so callers are safe. Let's look inside the functions.

In bdrv_co_preadv_part() and bdrv_aligned_pwritev() we only pass bytes
to other already int64_t interfaces (and some obviously safe
calculations), it's OK.

In bdrv_co_do_zero_pwritev() aligned_bytes may become large now, still
it's passed to bdrv_aligned_pwritev which supports int64_t bytes.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-15-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, prepare bdrv_aligned_preadv() now.

Make the bytes variable in bdrv_padding_rmw_read() int64_t, as it is
only used for pass-through to bdrv_aligned_preadv().

All bdrv_aligned_preadv() callers are safe as type is widening. Let's
look inside:

 - add a new-style assertion that request is good.
 - callees bdrv_is_allocated(), bdrv_co_do_copy_on_readv() supports
   int64_t bytes
 - conversion of bytes_remaining is OK, as we never have requests
   overflowing BDRV_MAX_LENGTH
 - looping through bytes_remaining is ok, num is updated to int64_t
   - for bdrv_driver_preadv we have same limit of max_transfer
   - qemu_iovec_memset is OK, as bytes+qiov_offset should not overflow
     qiov->size anyway (thanks to bdrv_check_qiov_request())

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-14-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, prepare bdrv_co_do_copy_on_readv() now.

'bytes' type widening, so callers are safe. Look at the function
itself:

bytes, skip_bytes and progress become int64_t.

bdrv_round_to_clusters() is OK, cluster_bytes now may be large.
trace_bdrv_co_do_copy_on_readv() is OK

looping through cluster_bytes is still OK.

pnum is still capped to max_transfer, and to MAX_BOUNCE_BUFFER when we
are going to do COR operation. Therefor calculations in
qemu_iovec_from_buf() and bdrv_driver_preadv() should not change.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-13-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, prepare bdrv_aligned_pwritev() now and convert the dependencies:
bdrv_co_write_req_prepare() and bdrv_co_write_req_finish() to signed
type bytes.

Conversion of bdrv_co_write_req_prepare() and
bdrv_co_write_req_finish() is definitely safe, as all requests in
block/io must not overflow BDRV_MAX_LENGTH. Still add assertions.

For bdrv_aligned_pwritev() 'bytes' type is widened, so callers are
safe. Let's check usage of the parameter inside the function.

Passing to bdrv_co_write_req_prepare() and bdrv_co_write_req_finish()
is OK.

Passing to qemu_iovec_* is OK after new assertion. All other callees
are already updated to int64_t.

Checking alignment is not changed, offset + bytes and qiov_offset +
bytes calculations are safe (thanks to new assertions).

max_transfer is kept to be int for now. It has a default of INT_MAX
here, and some drivers may rely on it. It's to be refactored later.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-12-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, prepare bdrv_co_do_pwrite_zeroes() now.

Callers are safe, as converting int to int64_t is safe. Concentrate on
'bytes' usage in the function (thx to Eric Blake):

    compute 'int tail' via % 'int alignment' - safe
    fragmentation loop 'int num' - still fragments with a cap on
      max_transfer

    use of 'num' within the loop
    MIN(bytes, max_transfer) as well as %alignment - still works, so
         calculations in if (head) {} are safe
    clamp size by 'int max_write_zeroes' - safe
    drv->bdrv_co_pwrite_zeroes(int) - safe because of clamping
    clamp size by 'int max_transfer' - safe
    buf allocation is still clamped to max_transfer
    qemu_iovec_init_buf(size_t) - safe because of clamping
    bdrv_driver_pwritev(uint64_t) - safe

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-11-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver wrappers parameters which are already 64bit to
signed type.

Requests in block/io.c must never exceed BDRV_MAX_LENGTH (which is less
than INT64_MAX), which makes the conversion to signed 64bit type safe.

Add corresponding assertions.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-10-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

All requests in block/io must not overflow BDRV_MAX_LENGTH, all
external users of BdrvTrackedRequest already have corresponding
assertions, so we are safe. Add some assertions still.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-9-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

Operations with qiov add more restrictions on bytes, let's cover it.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-8-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

The function is called from 64bit io handlers, and bytes is just passed
to throttle_account() which is 64bit too (unsigned though). So, let's
convert intermediate argument to 64bit too.

This patch is a first in the 64-bit-blocklayer series, so we are
generally moving to int64_t for both offset and bytes parameters on all
io paths. Main motivation is realization of 64-bit write_zeroes
operation for fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

Patch-correctness audit by Eric Blake:

  Caller has 32-bit, this patch now causes widening which is safe:
  block/block-backend.c: blk_do_preadv() passes 'unsigned int'
  block/block-backend.c: blk_do_pwritev_part() passes 'unsigned int'
  block/throttle.c: throttle_co_pwrite_zeroes() passes 'int'
  block/throttle.c: throttle_co_pdiscard() passes 'int'

  Caller has 64-bit, this patch fixes potential bug where pre-patch
  could narrow, except it's easy enough to trace that callers are still
  capped at 2G actions:
  block/throttle.c: throttle_co_preadv() passes 'uint64_t'
  block/throttle.c: throttle_co_pwritev() passes 'uint64_t'

  Implementation in question: block/throttle-groups.c
  throttle_group_co_io_limits_intercept() takes 'unsigned int bytes'
  and uses it: argument to util/throttle.c throttle_account(uint64_t)

  All safe: it patches a latent bug, and does not introduce any 64-bit
  gotchas once throttle_co_p{read,write}v are relaxed, and assuming
  throttle_account() is not buggy.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Message-Id: <20201211183934.169161-7-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

Make bdrv_pad_request() honest: return error if
qemu_iovec_init_extended() failed.

Update also bdrv_padding_destroy() to clean the structure for safety.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-6-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

Prepare for the following patch when bdrv_pad_request() will be able to
fail. Update the comments.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-5-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Signed-off-by: Eric Blake <eblake@redhat.com>

Calculation of sum may theoretically overflow, so use 64bit type and
add some good assertions.

Use int64_t constantly.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-4-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: tweak assertion order]
Signed-off-by: Eric Blake <eblake@redhat.com>

Actually, we can't extend the io vector in all cases. Handle possible
MAX_IOV and size_t overflows.

For now add assertion to callers (actually they rely on success anyway)
and fix them in the following patch.

Add also some additional good assertions to qemu_iovec_init_slice()
while being here.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

It's better to pass &error_abort than just assert that result is 0: on
crash, we'll immediately see the reason in the backtrace.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-2-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: fix iotest 206 fallout]
Signed-off-by: Eric Blake <eblake@redhat.com>

Commit f93e19fb adjusted various iotest whitespace discrepancies.
But another one snuck in during 61623f82, and we missed the
semantic merge conflict at the time because 185 is not run as part of
the default 'make check'.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210202185914.614705-1-eblake@redhat.com>
[eblake: adjust commit message]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Machine queue, 2021-02-02

Feature:
* nvdimm: read-only file support (Stefan Hajnoczi)

# gpg: Signature made Tue 02 Feb 2021 19:27:21 GMT
# gpg:                using RSA key 5A322FD5ABC4D3DBACCFD1AA2807936F984DC5A6
# gpg:                issuer "ehabkost@redhat.com"
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost-gl/tags/machine-next-pull-request:
  nvdimm: check -object memory-backend-file, readonly=on option
  hostmem-file: add readonly=on|off option
  memory: add readonly support to memory_region_init_ram_from_file()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Block layer patches:

- Fix double processing of nodes in bdrv_set_aio_context()
- Fix potential hang in block export shutdown
- block/nvme: Minor tracing improvements
- iotests: Some more fixups for the 'check' rewrite
- MAINTAINERS: Add Vladimir as co-maintainer for Block Jobs

# gpg: Signature made Tue 02 Feb 2021 16:26:02 GMT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  block: Fix VM size column width in bdrv_snapshot_dump()
  block/nvme: Trace NVMe spec version supported by the controller
  block/nvme: Properly display doorbell stride length in trace event
  iotests: Fix -makecheck output
  iotests: check: return 1 on failure
  iotests: Revert emulator selection to old behaviour
  iotests/297: pylint: ignore too many statements
  block: move blk_exp_close_all() to qemu_cleanup()
  block: Avoid processing BDS twice in bdrv_set_aio_context_ignore()
  MAINTAINERS: Add Vladimir as co-maintainer for Block Jobs

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

size_to_str() can return a size like "4.24 MiB", with a single digit
integer part and two fractional digits. This is eight characters, but
commit b39847a5 changed the format string to only reserve seven
characters for the column.

This can result in unaligned columns, which in turn changes the output of
iotests case 267 because exceeding the column size defeats the attempt
to filter the size out of the output (observed with the ppc64 emulator).
The resulting change is only a whitespace change, but since commit
f203080b this is enough for iotests to consider the test failed.

Taking a character away from the tag name column and adding it to the VM
size column doesn't change anything in the common case (the tag name is
left justified, the VM size is right justified), but fixes this case.

Fixes: b39847a5
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210202155911.179865-1-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

NVMe controllers implement different versions of the spec,
and different features of it. It is useful to gather this
information when debugging.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210127212137.3482291-3-philmd@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Commit 15b2260b ("block/nvme: Trace controller capabilities")
misunderstood the doorbell stride value from the datasheet, use
the correct one. The 'doorbell_scale' variable used few lines
later is correct.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210127212137.3482291-2-philmd@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

For -makecheck, the old 'check' implementation skipped the output when
starting a test. It only had the condensed output at the end of a test.

testrunner.py prints the normal output when starting a test even for
-makecheck. This output contains '\r' at the end so that it can be
overwritten with the result at the end of the test. However, for
-makecheck this is shorter output in a different format, so effectively
we end up with garbled output that mixes both output forms.

Revert to the old behaviour of only printing a message after the test
had completed in -makecheck mode.

Fixes: d74c754c
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210201161024.127921-1-kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

We should indicate failure by exit code, not only output.

Reported-by: Peter Maydell
Fixes: f203080b
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210201085041.3079-1-vsementsov@virtuozzo.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

If the qemu-system-{arch} binary for the host architecture can't be
found, the old 'check' implementation selected the alphabetically first
system emulator binary that it could find. The new Python implementation
just uses the first result of glob.iglob(), which has an undefined
order.

This is a problem that breaks CI because the iotests aren't actually
prepared to run on any emulator. They should be, so this is really a bug
in the failing test cases that should be fixed there, but as a quick
fix, let's revert to the old behaviour to let CI runs succeed again.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210202142802.119999-1-kwolf@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Ignore two complains, which now lead to 297 failure on testenv.py and
testrunner.py.

Fixes: 2e5a2f57
Fixes: d74c754c
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210129161323.615027-1-vsementsov@virtuozzo.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Move blk_exp_close_all() from bdrv_close() to qemu_cleanup(), before
bdrv_drain_all_begin().

Export drivers may have coroutines yielding at some point in the block
layer, so we need to shut them down before draining the block layer,
as otherwise they may get stuck blk_wait_while_drained().

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1900505


Signed-off-by: Sergio Lopez <slp@redhat.com>
Message-Id: <20210201125032.44713-3-slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Some graphs may contain an indirect reference to the first BDS in the
chain that can be reached while walking it bottom->up from one its
children.

Doubling-processing of a BDS is especially problematic for the
aio_notifiers, as they might attempt to work on both the old and the
new AIO contexts.

To avoid this problem, add every child and parent to the ignore list
before actually processing them.

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Sergio Lopez <slp@redhat.com>
Message-Id: <20210201125032.44713-2-slp@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

I'm developing Qemu backup for several years, and finally new backup
architecture, including block-copy generic engine and backup-top filter
landed upstream, great thanks to reviewers and especially to
Max Reitz!

I also have plans of moving other block-jobs onto block-copy, so that
we finally have one generic block copying path, fast and well-formed.

So, now I suggest to bring all parts of backup architecture into
"Block Jobs" subsystem (actually, aio_task is shared with qcow2 and
qemu-co-shared-resource can be reused somewhere else, but I'd keep an
eye on them in context of block-jobs) and add myself as co-maintainer.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210128144144.27617-1-vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

Check that -device nvdimm,unarmed=on is used when -object
memory-backend-file,readonly=on and document that -device
nvdimm,unarmed=on|off controls whether the NVDIMM appears read-only to
the guest.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20210104171320.575838-4-stefanha@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

Let -object memory-backend-file work on read-only files when the
readonly=on option is given. This can be used to share the contents of a
file between multiple guests while preventing them from consuming
Copy-on-Write memory if guests dirty the pages, for example.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20210104171320.575838-3-stefanha@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

There is currently no way to open(O_RDONLY) and mmap(PROT_READ) when
creating a memory region from a file. This functionality is needed since
the underlying host file may not allow writing.

Add a bool readonly argument to memory_region_init_ram_from_file() and
the APIs it calls.

Extend memory_region_init_ram_from_file() rather than introducing a
memory_region_init_rom_from_file() API so that callers can easily make a
choice between read/write and read-only at runtime without calling
different APIs.

No new RAMBlock flag is introduced for read-only because it's unclear
whether RAMBlocks need to know that they are read-only. Pass a bool
readonly argument instead.

Both of these design decisions can be changed in the future. It just
seemed like the simplest approach to me.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20210104171320.575838-2-stefanha@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

Pull request

# gpg: Signature made Mon 01 Feb 2021 15:46:52 GMT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha-gitlab/tags/tracing-pull-request:
  trace: update docs with meson build information
  trace: document how to specify multiple --trace patterns
  simpletrace: build() missing 2 required positional arguments
  trace: make the 'log' backend timestamp configurable
  error: rename error_with_timestamp to message_with_timestamp
  trace: add meson custom_target() depend_files for tracetool
  tracetool: also strip %l and %ll from systemtap format strings
  tracetool: fix "PRI" macro decoding
  trace: recommend "log" backend for getting started with tracing
  tracing: convert documentation to rST
  trace: fix simpletrace doc mismerge

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

The documentation still refers to the makefile and the old sub-directory
layout. Meson works differently: tracetool output is placed into the
builddir with mangled filenames like <builddir>/trace/trace-accel_kvm.h
for the accel/kvm/ trace.h definition.

This meson setup also requires a manually-created accel/kvm/trace.h file
that #includes the <builddir>/trace/trace-accel_kvm.h file. Document
this!

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20210112165859.225534-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

It is possible to repeat the --trace option to specify multiple
patterns. This may be preferrable to users who do not want to create a
file with a list of patterns.

Suggested-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210112165859.225534-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Commit 4e66c9ef "tracetool: add input filename and line number to
Event" forgot to add a line number and a filename argument at one
build method call site.

Traceback (most recent call last):
  File "./scripts/simpletrace.py", line 261, in <module>
    run(Formatter())
  File "./scripts/simpletrace.py", line 236, in run
    process(events, sys.argv[2], analyzer, read_header=read_header)
  File "./scripts/simpletrace.py", line 177, in process
    dropped_event =
      Event.build("Dropped_Event(uint64_t num_events_dropped)")
TypeError: build() missing 2 required positional arguments:
  'lineno' and 'filename'

Add the missing arguments.

Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20210131173415.3392-1-vr_qemu@t-online.de
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Timestamps in tracing output can be distracting. Make it possible to
control tid/timestamp printing with -msg timestamp=on|off. The default
is no tid/timestamps. Previously they were always printed.

Suggested-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210125113507.224287-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

The -msg timestamp=on|off option controls whether a timestamp is printed
with error_report() messages. The "-msg" name suggests that this option
has a wider effect than just error_report(). The next patch extends it
to the 'log' trace backend, so rename the variable from
error_with_timestamp to message_with_timestamp.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210125113507.224287-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Re-generate tracetool output when the tracetool source code changes. Use
the same approach as qapi_gen_depends and introduce a tracetool_depends
files list so meson is aware of the dependencies.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210125110958.214017-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>