On 12/30/25 11:33 PM, Pierrick Bouvier wrote:
Writing plugins in C can be sometimes tedious, especially when using Glib to
keep track of execution state. We can directly use the same C API but write our
plugin in C++, benefiting from its great standard library offering strings,
smart pointers, data structures and synchronization mechanisms.
It's common for downstream QEMU forks to provide C++ for plugins, like this:
- https://github.com/panda-re/panda/tree/dev/panda/plugins
- https://github.com/FlorentRevest/DejaView/tree/main/src/qemu_plugin
Hopefully this will help more people to use upstream QEMU, and as a benefit, get
their contribution back and help to develop plugins ecosystem upstream directly.
This series first cleans up build system for plugins, factorizing details
between contrib/plugins and tests/tcg/plugins folders.
Then, we perform codebase cleanups to fix conflicts between existing headers
and C++ headers.
After that, we can update the C++ standard used by QEMU, to benefit fully
from latest updates of the language.
Finally, we define an empty C++ plugin, making sure we can keep track of
possible regression in qemu-plugin header.
Note: This series is *not* a trojan horse to bring C++ in QEMU
codebase, nor to define an alternative C++ API for plugins. It's just enabling
more users to get the most out of existing C plugin API.
CI: https://gitlab.com/pbo-linaro/qemu/-/pipelines/2239199381
Pierrick Bouvier (11):
plugins: move win32_linker.c file to plugins directory
plugins: factorize plugin dependencies and library details
plugins: use complete filename for defining plugins sources
plugins: define plugin API symbols as extern "C" when compiling in C++
include: qemu/ctype.h -> qemu/qemu-ctype.h
include: qemu/coroutine.h -> qemu/qemu-coroutine.h
meson: fix supported compiler arguments in other languages than C
meson: enable cpp (optionally) for plugins
qga/vss-win32: fix clang warning with C++20
meson: update C++ standard to C++23
contrib/plugins: add empty cpp plugin
meson.build | 24 ++--
block/parallels.h | 2 +-
block/qcow2.h | 2 +-
fsdev/qemu-fsdev-throttle.h | 2 +-
hw/9pfs/9p.h | 2 +-
include/block/block-global-state.h | 2 +-
include/block/block-hmp-cmds.h | 2 +-
include/block/block-io.h | 2 +-
include/block/reqlist.h | 2 +-
include/block/throttle-groups.h | 2 +-
include/qemu/coroutine_int.h | 2 +-
include/qemu/job.h | 2 +-
.../qemu/{coroutine.h => qemu-coroutine.h} | 0
include/qemu/{ctype.h => qemu-ctype.h} | 0
include/qemu/qemu-plugin.h | 8 ++
migration/migration.h | 2 +-
ui/console-priv.h | 2 +-
block.c | 2 +-
block/block-copy.c | 2 +-
block/io_uring.c | 2 +-
block/linux-aio.c | 2 +-
block/mirror.c | 2 +-
block/progress_meter.c | 2 +-
block/ssh.c | 2 +-
block/vdi.c | 2 +-
block/vvfat.c | 2 +-
chardev/char.c | 2 +-
gdbstub/gdbstub.c | 2 +-
hw/9pfs/coth.c | 2 +-
hw/block/virtio-blk.c | 2 +-
hw/core/bus.c | 2 +-
hw/core/qdev-properties-system.c | 2 +-
hw/core/qdev-properties.c | 2 +-
hw/hyperv/syndbg.c | 2 +-
hw/nvme/nguid.c | 2 +-
hw/s390x/ccw-device.c | 2 +-
hw/s390x/ipl.c | 2 +-
hw/s390x/s390-virtio-ccw.c | 2 +-
hw/scsi/scsi-generic.c | 2 +-
migration/migration.c | 2 +-
migration/rdma.c | 2 +-
monitor/fds.c | 2 +-
monitor/hmp.c | 2 +-
nbd/client-connection.c | 2 +-
net/colo-compare.c | 2 +-
net/net.c | 2 +-
net/tap-solaris.c | 2 +-
{contrib/plugins => plugins}/win32_linker.c | 0
qapi/qapi-util.c | 2 +-
qapi/qmp-dispatch.c | 2 +-
qobject/json-parser.c | 2 +-
target/ppc/ppc-qmp-cmds.c | 2 +-
target/riscv/cpu.c | 2 +-
target/riscv/riscv-qmp-cmds.c | 2 +-
tests/qtest/libqtest.c | 2 +-
tests/qtest/migration/migration-util.c | 2 +-
tests/unit/test-aio-multithread.c | 2 +-
tests/vhost-user-bridge.c | 2 +-
ui/console.c | 2 +-
ui/keymaps.c | 2 +-
ui/ui-qmp-cmds.c | 2 +-
util/cutils.c | 2 +-
util/id.c | 2 +-
util/qemu-co-shared-resource.c | 2 +-
util/qemu-co-timeout.c | 2 +-
util/qemu-coroutine-io.c | 2 +-
util/readline.c | 2 +-
util/thread-pool.c | 2 +-
contrib/plugins/cpp.cpp | 119 ++++++++++++++++++
contrib/plugins/meson.build | 25 ++--
plugins/meson.build | 15 ++-
qga/vss-win32/requester.cpp | 6 +-
tests/tcg/plugins/meson.build | 18 +--
73 files changed, 237 insertions(+), 104 deletions(-)
rename include/qemu/{coroutine.h => qemu-coroutine.h} (100%)
rename include/qemu/{ctype.h => qemu-ctype.h} (100%)
rename {contrib/plugins => plugins}/win32_linker.c (100%)
create mode 100644 contrib/plugins/cpp.cpp
v2 sent:
https://lore.kernel.org/qemu-devel/[email protected]/T/#t
