Add a new .save_prepare() handler to struct SaveVMHandlers. This handler
is called early, even before migration starts, and can be used by
devices to perform early checks.

Refactor migrate_init() to be able to return errors and call
.save_prepare() from there.

Suggested-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

Initialization of mig_stats, compression_counters and VFIO bytes
transferred is hard-coded in migration code path and snapshot code path.

Make the code cleaner by initializing them in migrate_init().

Suggested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

If a device with enable-migration=on is added and it causes a migration
blocker, adding the device should fail with a proper error.

This is not the case with multiple device migration blocker when the
blocker already exists. If the blocker already exists and a device with
enable-migration=on is added which causes a migration blocker, adding
the device will succeed.

Fix it by failing adding the device in such case.

Fixes: 8bbcb64a ("vfio/migration: Make VFIO migration non-experimental")
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

The functions in target.c are not static, yet they don't have a proper
migration prefix. Add such prefix.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

Now that P2P support has been added to VFIO migration, allow migration
of multiple devices if all of them support P2P migration.

Single device migration is allowed regardless of P2P migration support.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: YangHang Liu <yanghliu@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

VFIO migration uAPI defines an optional intermediate P2P quiescent
state. While in the P2P quiescent state, P2P DMA transactions cannot be
initiated by the device, but the device can respond to incoming ones.
Additionally, all outstanding P2P transactions are guaranteed to have
been completed by the time the device enters this state.

The purpose of this state is to support migration of multiple devices
that might do P2P transactions between themselves.

Add support for P2P migration by transitioning all the devices to the
P2P quiescent state before stopping or starting the devices. Use the new
VMChangeStateHandler prepare_cb to achieve that behavior.

This will allow migration of multiple VFIO devices if all of them
support P2P migration.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Tested-by: YangHang Liu <yanghliu@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

Move the PRE_COPY and RUNNING state checks to helper functions.

This is in preparation for adding P2P VFIO migration support, where
these helpers will also test for PRE_COPY_P2P and RUNNING_P2P states.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: YangHang Liu <yanghliu@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

Add qdev_add_vm_change_state_handler_full() variant that allows setting
a prepare callback in addition to the main callback.

This will facilitate adding P2P support for VFIO migration in the
following patches.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: YangHang Liu <yanghliu@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

Add prepare callback to struct VMChangeStateEntry.

The prepare callback is optional and can be set by the new function
qemu_add_vm_change_state_handler_prio_full() that allows setting this
callback in addition to the main callback.

The prepare callbacks and main callbacks are called in two separate
phases: First all prepare callbacks are called and only then all main
callbacks are called.

The purpose of the new prepare callback is to allow all devices to run a
preliminary task before calling the devices' main callbacks.

This will facilitate adding P2P support for VFIO migration where all
VFIO devices need to be put in an intermediate P2P quiescent state
before being stopped or started by the main callback.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Tested-by: YangHang Liu <yanghliu@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

Changing the device state from STOP_COPY to STOP can take time as the
device may need to free resources and do other operations as part of the
transition. Currently, this is done in vfio_save_complete_precopy() and
therefore it is counted in the migration downtime.

To avoid this, change the device state from STOP_COPY to STOP in
vfio_save_cleanup(), which is called after migration has completed and
thus is not part of migration downtime.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Tested-by: YangHang Liu <yanghliu@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

trivial patches for 2023-09-08

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* tag 'pull-trivial-patches' of https://gitlab.com/mjt0k/qemu

: (22 commits)
  qxl: don't assert() if device isn't yet initialized
  hw/net/vmxnet3: Fix guest-triggerable assert()
  tests/qtest/usb-hcd: Remove the empty "init" tests
  target/ppc: use g_free() in test_opcode_table()
  hw/ppc: use g_free() in spapr_tce_table_post_load()
  trivial: Simplify the spots that use TARGET_BIG_ENDIAN as a numeric value
  accel/tcg: Fix typo in translator_io_start() description
  tests/qtest/test-hmp: Fix migrate_set_parameter xbzrle-cache-size test
  docs tests: Fix use of migrate_set_parameter
  qemu-options.hx: Rephrase the descriptions of the -hd* and -cdrom options
  hw/display/xlnx_dp: update comments
  block: spelling fixes
  misc/other: spelling fixes
  qga/: spelling fixes
  tests/: spelling fixes
  scripts/: spelling fixes
  include/: spelling fixes
  audio: spelling fixes
  xen: spelling fix
  riscv: spelling fixes
  ...

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

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

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* 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>

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230906093210.339585-8-den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: Wording improvement]
Signed-off-by: Eric Blake <eblake@redhat.com>

Closing stderr earlier is good for daemonized qemu-nbd under ssh
earlier, but breaks the case where -v is being used to track what is
happening in the server, as in iotest 233.

When we know we are verbose, we should preserve original stderr and
restore it once the setup stage is done. This commit restores the
original behavior with -v option. In this case original output
inside the test is kept intact.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
CC: Hanna Reitz <hreitz@redhat.com>
CC: Mike Maslenkin <mike.maslenkin@gmail.com>
Fixes: 5c56dd27 ("qemu-nbd: fix regression with qemu-nbd --fork run over ssh")
Message-ID: <20230906093210.339585-7-den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
[eblake: fix build by avoiding stderr as struct member name]
Signed-off-by: Eric Blake <eblake@redhat.com>

Pull request

- Jeuk Kim's emulated UFS device
- Fabiano Rosas' IOThread GSource "name" debugging aid

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* tag 'block-pull-request' of https://gitlab.com/stefanha/qemu

:
  tests/qtest: Introduce tests for UFS
  hw/ufs: Support for UFS logical unit
  hw/ufs: Support for Query Transfer Requests
  hw/ufs: Initial commit for emulated Universal-Flash-Storage
  iothread: Set the GSource "name" field

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

If the PCI BAR isn't yet mapped or was unmapped, QXL_IO_SET_MODE will
assert(). Instead, report a guest bug and keep going.

This can be reproduced with:

cat << EOF | ./qemu-system-x86_64 -vga qxl -m 2048 -nodefaults -qtest stdio
outl 0xcf8 0x8000101c
outl 0xcfc 0xc000
outl 0xcf8 0x80001001
outl 0xcfc 0x01000000
outl 0xc006 0x00
EOF

Fixes: https://gitlab.com/qemu-project/qemu/-/issues/1829



Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

The assert() that checks for valid MTU sizes can be triggered by
the guest (e.g. with the reproducer code from the bug ticket
https://gitlab.com/qemu-project/qemu/-/issues/517

 ). Let's avoid
this problem by simply logging the error and refusing to activate
the device instead.

Fixes: d05dcd94 ("net: vmxnet3: validate configuration values during activate")
Signed-off-by: Thomas Huth <thuth@redhat.com>
Cc: qemu-stable@nongnu.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
[Mjt: change format specifier from %d to %u for uint32_t argument]

These tests do nothing additional compared to the other test,
so let's remove the empty functions to avoid wasting some few
precious test cycles here.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

table[i] is allocated in create_new_table() using g_new().

Use g_free(table[i]) instead of free(table[i]) to comply with QEMU low
level memory management guidelines.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
[Mjt: minor commit comment tweak]

tcet->mig_table is copied from tcet->table, which in turn is created
in spapr_tce_alloc_table() using g_new0().

Use g_free() instead of free() to deallocate it.

Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
[Mjt: fix commit comments]

TARGET_BIG_ENDIAN is *always* defined, either as 0 for little endian
targets or as 1 for big endian targets. So we can use this as a value
directly in places that need such a 0 or 1 for some reason, instead
of taking a detour through an additional local variable or something
similar.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

Missed while reviewing commit dfd1b812
("accel/tcg: Introduce translator_io_start").

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

The command always fails with "Error: Parameter 'xbzrle_cache_size'
expects a power of two no less than the target page size".  The test
passes anyway.  Change the argument from 1 to 64k to make the test a
bit more useful.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

docs/multi-thread-compression.txt uses parameter names with
underscores instead of dashes.  Wrong since day one.

docs/rdma.txt, tests/qemu-iotests/181, and tests/qtest/test-hmp.c are
wrong the same way since commit cbde7be9 (v6.0.0).  Hard to see,
as test-hmp doesn't check whether the commands work, and iotest 181
appears to be unaffected.

Fixes: 263170e6 (docs: Add a doc about multiple thread compression)
Fixes: cbde7be9 (migrate: remove QMP/HMP commands for speed, downtime and cache size)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

The current description says that these options will create a device
on the IDE bus, which is only true on x86. So rephrase these sentences
a little bit to speak of "default bus" instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

Clarify somewhat misleading code comments.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>

with some rewording in
 tests/qemu-iotests/298
 tests/qtest/fuzz/generic_fuzz.c
 tests/unit/test-throttle.c
as suggested by Eric.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Eric Blake <eblake@redhat.com>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Acked-by: Alistair Francis <alistair.francis@wdc.com>

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Brian Cain <bcain@quicinc.com>

The file has been converted to .rst a while ago - make sure that the
references in the trace-events files are pointing to the right location
now.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

Move the code from main() and nbd_client_thread() into the specific
helper. This code is going to be grown.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230906093210.339585-6-den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

We pass other parameters into nbd_client_thread() in this way. This patch
makes the code more consistent.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230906093210.339585-5-den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

We pass other parameters into nbd_client_thread() in this way. This patch
makes the code more consistent.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230906093210.339585-4-den@openvz.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: Note that this also cleans up a -Wshadow issue, first
introduced in e5b815b0]
Signed-off-by: Eric Blake <eblake@redhat.com>