On Mon, Oct 05, 2020 at 05:58:41PM +0200, Kevin Wolf wrote: > Some QMP command handlers can block the main loop for a relatively long > time, for example because they perform some I/O. This is quite nasty. > Allowing such handlers to run in a coroutine where they can yield (and > therefore release the BQL) while waiting for an event such as I/O > completion solves the problem. > > This series adds the infrastructure to allow this and switches > block_resize to run in a coroutine as a first example. > > This is an alternative solution to Marc-André's "monitor: add > asynchronous command type" series. > > v8: > - Replaced bdrv_co_move_to_aio_context() with bdrv_co_enter()/leave(), > added bdrv_co_lock()/unlock() and fixed the iothread support in > qmp_block_resize() with the new functions [Stefan] > - More detailed documentation of 'coroutine' flag for commands [Markus] > - Improved comment for dropping out of coroutine context in > qmp_dispatch() [Markus] > - Coding style changes [Markus] > - Resolve some more merge conflicts on rebase > > v7: > - Added patch 2 to add a Monitor parameter to monitor_get_cpu_index(), > too [Markus] > - Let monitor_set_cur() return the old monitor [Markus] > - Fixed comment about linking stub objects in test-util-sockets [Markus] > - More detailed commit message for per-coroutine current monitor and > document that monitor_set_cur(NULL) must be called eventually [Markus] > - Resolve some merge conflicts on rebase > > v6: > - Fixed cur_mon behaviour: It should always point to the Monitor while > we're in the handler coroutine, but be NULL while the handler > coroutines has yielded. [Markus] > - Give HMP handlers the coroutine option, too, because they will call > QMP handlers, and life is easier when we know whether we are in > coroutine context or not. > - Fixed block_resize for block devices in iothreads and for HMP > - Resolved some merge conflict with QAPI generator and monitor > refactorings that were merged in the meantime > > v5: > - Improved comments and documentation [Markus] > > v4: > - Forbid 'oob': true, 'coroutine': true [Markus] > - Removed Python type hints [Markus] > - Introduced separate bool qmp_dispatcher_co_shutdown to make it clearer > how a shutdown request is signalled to the dispatcher [Markus] > - Allow using aio_poll() with iohandler_ctx and use that instead of > aio_bh_poll() [Markus] > - Removed coroutine_fn from qmp_block_resize() again because at least > one caller (HMP) calls it outside of coroutine context [Markus] > - Tried to make the synchronisation between dispatcher and the monitor > thread clearer, and fixed a race condition > - Improved documentation and comments > > v3: > - Fix race between monitor thread and dispatcher that could schedule the > dispatcher coroutine twice if a second requests comes in before the > dispatcher can wake up [Patchew] > > v2: > - Fix typo in a commit message [Eric] > - Use hyphen instead of underscore for the test command [Eric] > - Mark qmp_block_resize() as coroutine_fn [Stefan] > > > Kevin Wolf (14): > monitor: Add Monitor parameter to monitor_set_cpu() > monitor: Add Monitor parameter to monitor_get_cpu_index() > monitor: Use getter/setter functions for cur_mon > hmp: Update current monitor only in handle_hmp_command() > qmp: Assert that no other monitor is active > qmp: Call monitor_set_cur() only in qmp_dispatch() > monitor: Make current monitor a per-coroutine property > qapi: Add a 'coroutine' flag for commands > qmp: Move dispatcher to a coroutine > hmp: Add support for coroutine command handlers > util/async: Add aio_co_reschedule_self() > block: Add bdrv_co_enter()/leave() > block: Add bdrv_lock()/unlock() > block: Convert 'block_resize' to coroutine > > qapi/block-core.json | 3 +- > docs/devel/qapi-code-gen.txt | 29 ++++++ > docs/sphinx/qapidoc.py | 2 +- > include/block/aio.h | 10 ++ > include/block/block.h | 31 ++++++ > include/monitor/monitor.h | 7 +- > include/qapi/qmp/dispatch.h | 5 +- > monitor/monitor-internal.h | 7 +- > audio/wavcapture.c | 8 +- > block.c | 50 +++++++++ > blockdev.c | 16 +-- > dump/dump.c | 2 +- > hw/core/machine-hmp-cmds.c | 2 +- > hw/scsi/vhost-scsi.c | 2 +- > hw/virtio/vhost-vsock.c | 2 +- > migration/fd.c | 4 +- > monitor/hmp-cmds.c | 4 +- > monitor/hmp.c | 44 ++++++-- > monitor/misc.c | 38 +++---- > monitor/monitor.c | 101 ++++++++++++++++-- > monitor/qmp-cmds-control.c | 2 + > monitor/qmp-cmds.c | 2 +- > monitor/qmp.c | 131 +++++++++++++++++------- > net/socket.c | 2 +- > net/tap.c | 6 +- > qapi/qmp-dispatch.c | 65 +++++++++++- > qapi/qmp-registry.c | 3 + > qga/main.c | 2 +- > softmmu/cpus.c | 2 +- > stubs/monitor-core.c | 10 +- > tests/test-qmp-cmds.c | 10 +- > tests/test-util-sockets.c | 12 +-- > trace/control.c | 2 +- > util/aio-posix.c | 8 +- > util/async.c | 30 ++++++ > util/qemu-error.c | 6 +- > util/qemu-print.c | 3 +- > util/qemu-sockets.c | 1 + > scripts/qapi/commands.py | 10 +- > scripts/qapi/expr.py | 11 +- > scripts/qapi/introspect.py | 2 +- > scripts/qapi/schema.py | 13 ++- > tests/qapi-schema/test-qapi.py | 7 +- > hmp-commands.hx | 1 + > tests/qapi-schema/meson.build | 1 + > tests/qapi-schema/oob-coroutine.err | 2 + > tests/qapi-schema/oob-coroutine.json | 2 + > tests/qapi-schema/oob-coroutine.out | 0 > tests/qapi-schema/qapi-schema-test.json | 1 + > tests/qapi-schema/qapi-schema-test.out | 2 + > 50 files changed, 573 insertions(+), 143 deletions(-) > create mode 100644 tests/qapi-schema/oob-coroutine.err > create mode 100644 tests/qapi-schema/oob-coroutine.json > create mode 100644 tests/qapi-schema/oob-coroutine.out > > -- > 2.25.4 > Reviewed-by: Stefan Hajnoczi