Merge tag 'pull-nbd-2023-09-07-v2' of https://repo.or.cz/qemu/ericb into staging

NBD patches for 2023-09-07

- Andrey Drobyshev - fix regression in iotest 197 under -nbd
- Stefan Hajnoczi - allow co

Merge tag 'pull-nbd-2023-09-07-v2' of https://repo.or.cz/qemu/ericb into staging

NBD patches for 2023-09-07

- Andrey Drobyshev - fix regression in iotest 197 under -nbd
- Stefan Hajnoczi - allow coroutine read and write context to split
across threads
- Philippe Mathieu-Daudé - remove a VLA allocation
- Denis V. Lunev - fix regression in iotest 233 with qemu-nbd -v --fork

# -----BEGIN PGP SIGNATURE-----
#
# iQEzBAABCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAmT7EsUACgkQp6FrSiUn
# Q2qiKgf9EqCWPmcsH2nvXrDvZmDc0/I4tineaNY+hSdPtSb6RFA1IH8AvzkrkPYU
# 9ojX6QFp1Z30fUs+pwweQhBMYta03QyjCFhsbPRmDq391dtIDCeww3o+RD1kw/pg
# 2ZC+P9N1U3pi2Hi8FhxH17GYYgOQnHMKM9gt1V7JOQvFsDFWbTo9sFj8p/BPoWxV
# I3TeLQDWqVnNjf57lG2pwhdKc8DbKoqRmA3XNiXiKI5inEBeRJsTdMMGn4YWpwJE
# Y5imM/PbyCqRKQ6MYyJenVk4QVTe1IKO6D4vf1ZHLDBEiaw9NaeYHlk6lnDC4O9v
# PeTycAwND6cMKYlKMyEzcJXv9IdRBw==
# =jAZi
# -----END PGP SIGNATURE-----
# gpg: Signature made Fri 08 Sep 2023 08:25:41 EDT
# gpg: using RSA key 71C2CC22B1C4602927D2F3AAA7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>" [full]
# gpg: aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>" [full]
# gpg: aka "[jpeg image of size 6874]" [full]
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2 F3AA A7A1 6B4A 2527 436A

* tag 'pull-nbd-2023-09-07-v2' of https://repo.or.cz/qemu/ericb:
qemu-nbd: document -v behavior in respect to --fork in man
qemu-nbd: Restore "qemu-nbd -v --fork" output
qemu-nbd: invent nbd_client_release_pipe() helper
qemu-nbd: put saddr into into struct NbdClientOpts
qemu-nbd: move srcpath into struct NbdClientOpts
qemu-nbd: define struct NbdClientOpts when HAVE_NBD_DEVICE is not defined
qemu-nbd: improve error message for dup2 error
util/iov: Avoid dynamic stack allocation
io: follow coroutine AioContext in qio_channel_yield()
io: check there are no qio_channel_yield() coroutines during ->finalize()
nbd: drop unused nbd_start_negotiate() aio_context argument
nbd: drop unused nbd_receive_negotiate() aio_context argument
qemu-iotests/197: use more generic commands for formats other than qcow2

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

show more ...

io: follow coroutine AioContext in qio_channel_yield()

The ongoing QEMU multi-queue block layer effort makes it possible for multiple
threads to process I/O in parallel. The nbd block driver is not

io: follow coroutine AioContext in qio_channel_yield()

The ongoing QEMU multi-queue block layer effort makes it possible for multiple
threads to process I/O in parallel. The nbd block driver is not compatible with
the multi-queue block layer yet because QIOChannel cannot be used easily from
coroutines running in multiple threads. This series changes the QIOChannel API
to make that possible.

In the current API, calling qio_channel_attach_aio_context() sets the
AioContext where qio_channel_yield() installs an fd handler prior to yielding:

qio_channel_attach_aio_context(ioc, my_ctx);
...
qio_channel_yield(ioc); // my_ctx is used here
...
qio_channel_detach_aio_context(ioc);

This API design has limitations: reading and writing must be done in the same
AioContext and moving between AioContexts involves a cumbersome sequence of API
calls that is not suitable for doing on a per-request basis.

There is no fundamental reason why a QIOChannel needs to run within the
same AioContext every time qio_channel_yield() is called. QIOChannel
only uses the AioContext while inside qio_channel_yield(). The rest of
the time, QIOChannel is independent of any AioContext.

In the new API, qio_channel_yield() queries the AioContext from the current
coroutine using qemu_coroutine_get_aio_context(). There is no need to
explicitly attach/detach AioContexts anymore and
qio_channel_attach_aio_context() and qio_channel_detach_aio_context() are gone.
One coroutine can read from the QIOChannel while another coroutine writes from
a different AioContext.

This API change allows the nbd block driver to use QIOChannel from any thread.
It's important to keep in mind that the block driver already synchronizes
QIOChannel access and ensures that two coroutines never read simultaneously or
write simultaneously.

This patch updates all users of qio_channel_attach_aio_context() to the
new API. Most conversions are simple, but vhost-user-server requires a
new qemu_coroutine_yield() call to quiesce the vu_client_trip()
coroutine when not attached to any AioContext.

While the API is has become simpler, there is one wart: QIOChannel has a
special case for the iohandler AioContext (used for handlers that must not run
in nested event loops). I didn't find an elegant way preserve that behavior, so
I added a new API called qio_channel_set_follow_coroutine_ctx(ioc, true|false)
for opting in to the new AioContext model. By default QIOChannel uses the
iohandler AioHandler. Code that formerly called
qio_channel_attach_aio_context() now calls
qio_channel_set_follow_coroutine_ctx(ioc, true) once after the QIOChannel is
created.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20230830224802.493686-5-stefanha@redhat.com>
[eblake: also fix migration/rdma.c]
Signed-off-by: Eric Blake <eblake@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-for-5.2-pull-request' into staging

Pull request trivial branch 20201027

# gpg: Signature made Tue 27 Oct 2020 16:29:47 GMT
# gpg:

Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-for-5.2-pull-request' into staging

Pull request trivial branch 20201027

# gpg: Signature made Tue 27 Oct 2020 16:29:47 GMT
# gpg: using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg: issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg: aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg: aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F 5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/trivial-branch-for-5.2-pull-request:
CHANGELOG: remove disused file
qdev: Fix two typos
scripts/qmp: delete 'qmp' script
cryptodev: Fix Lesser GPL version number
io: Fix Lesser GPL version number
cpus: Drop declaration of cpu_remove()
Makefile: Add *.[ch].inc files to cscope/ctags/TAGS
elf2dmp: Fix memory leak on main() error paths

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

show more ...

io: Fix Lesser GPL version number

There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "

io: Fix Lesser GPL version number

There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

show more ...

io: Fix Lesser GPL version number

There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "

io: Fix Lesser GPL version number

There is no "version 2" of the "Lesser" General Public License.
It is either "GPL version 2.0" or "Lesser GPL version 2.1".
This patch replaces all occurrences of "Lesser GPL version 2" with
"Lesser GPL version 2.1" in comment section.

Signed-off-by: Chetan Pant <chetan4windows@gmail.com>
Acked-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20201014134033.14095-1-chetan4windows@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-include-2016-07-12' into staging

Clean up #include "..." vs <...> and header guards

# gpg: Signature made Tue 12 Jul 2016 15:23:43 BST
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-include-2016-07-12' into staging

Clean up #include "..." vs <...> and header guards

# gpg: Signature made Tue 12 Jul 2016 15:23:43 BST
# gpg: using RSA key 0x3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-include-2016-07-12:
cris: Fix broken header guard in hw/cris/boot.h
Clean up decorations and whitespace around header guards
Clean up ill-advised or unusual header guards
libdecnumber: Don't error out on decNumberLocal.h re-inclusion
libdecnumber: Don't fool around with guards to avoid #include
Clean up header guards that don't match their file name
Drop Emacs local variables lists redundant with .dir-locals.el
spapr_pci: Include spapr.h instead of playing games with #error
tcg: Clean up tcg-target.h header guards
linux-user: Fix broken header guard in syscall_defs.h
linux-user: Clean up hostdep.h header guards
linux-user: Clean up target_structs.h header guards
linux-user: Clean up target_signal.h header guards
linux-user: Clean up target_cpu.h header guards
linux-user: Clean up target_syscall.h header guards
target-*: Clean up cpu.h header guards
scripts: New clean-header-guards.pl
Use #include "..." for our own headers, <...> for others

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

show more ...

Clean up ill-advised or unusual header guards

Cleaned up with scripts/clean-header-guards.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>

Merge remote-tracking branch 'remotes/berrange/tags/pull-io-next-2016-02-16-1' into staging

Merge I/O fixes 2016/02/16 v1

# gpg: Signature made Tue 16 Feb 2016 15:42:29 GMT using RSA key ID 15104FD

Merge remote-tracking branch 'remotes/berrange/tags/pull-io-next-2016-02-16-1' into staging

Merge I/O fixes 2016/02/16 v1

# gpg: Signature made Tue 16 Feb 2016 15:42:29 GMT using RSA key ID 15104FDF
# gpg: Good signature from "Daniel P. Berrange <dan@berrange.com>"
# gpg: aka "Daniel P. Berrange <berrange@redhat.com>"

* remotes/berrange/tags/pull-io-next-2016-02-16-1:
io: convert QIOChannelBuffer to use uint8_t instead of char
io: introduce helper for creating channels from file descriptors
io: improve docs for QIOChannelSocket async functions

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

show more ...

io: introduce helper for creating channels from file descriptors

Depending on what object a file descriptor refers to a different
type of IO channel will be needed - either a QIOChannelFile or
a QIO

io: introduce helper for creating channels from file descriptors

Depending on what object a file descriptor refers to a different
type of IO channel will be needed - either a QIOChannelFile or
a QIOChannelSocket. Introduce a qio_channel_new_fd() method
which will return the appropriate channel implementation.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

show more ...