Merge tag 'for-upstream' of https://repo.or.cz/qemu/kevin into staging

Block layer patches

- Code cleanups around block graph modification
- Simplify drain
- coroutine_fn correctness fixes, including splitting generated
  coroutine wrappers into co_wrapper (to be called only from
  non-coroutine context) and co_wrapper_mixed (both coroutine and
  non-coroutine context)
- Introduce a block graph rwlock

# gpg: Signature made Thu 15 Dec 2022 15:08:34 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

* tag 'for-upstream' of https://repo.or.cz/qemu/kevin: (50 commits)
  block: GRAPH_RDLOCK for functions only called by co_wrappers
  block: use co_wrapper_mixed_bdrv_rdlock in functions taking the rdlock
  block-coroutine-wrapper.py: introduce annotations that take the graph rdlock
  Mark assert_bdrv_graph_readable/writable() GRAPH_RD/WRLOCK
  graph-lock: TSA annotations for lock/unlock functions
  block: assert that graph read and writes are performed correctly
  block: remove unnecessary assert_bdrv_graph_writable()
  block: wrlock in bdrv_replace_child_noperm
  block: Fix locking in external_snapshot_prepare()
  test-bdrv-drain: Fix incorrrect drain assumptions
  clang-tsa: Add macros for shared locks
  clang-tsa: Add TSA_ASSERT() macro
  Import clang-tsa.h
  async: Register/unregister aiocontext in graph lock list
  graph-lock: Implement guard macros
  graph-lock: Introduce a lock to protect block graph operations
  block: Factor out bdrv_drain_all_begin_nopoll()
  block/dirty-bitmap: convert coroutine-only functions to co_wrapper
  block: convert bdrv_create to co_wrapper
  block-coroutine-wrapper.py: support also basic return types
  ...

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

1 files changed, 114 insertions, 0 deletions

diff --git a/include/qemu/clang-tsa.h b/include/qemu/clang-tsa.h
new file mode 100644
index 0000000000..ba06fb8c92
--- /dev/null
+++ b/include/qemu/clang-tsa.h
@@ -0,0 +1,114 @@
+#ifndef CLANG_TSA_H
+#define CLANG_TSA_H
+
+/*
+ * Copyright 2018 Jarkko Hietaniemi <jhi@iki.fi>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without
+ * limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/* http://clang.llvm.org/docs/ThreadSafetyAnalysis.html
+ *
+ * TSA is available since clang 3.6-ish.
+ */
+#ifdef __clang__
+#  define TSA(x)   __attribute__((x))
+#else
+#  define TSA(x)   /* No TSA, make TSA attributes no-ops. */
+#endif
+
+/* TSA_CAPABILITY() is used to annotate typedefs:
+ *
+ * typedef pthread_mutex_t TSA_CAPABILITY("mutex") tsa_mutex;
+ */
+#define TSA_CAPABILITY(x) TSA(capability(x))
+
+/* TSA_GUARDED_BY() is used to annotate global variables,
+ * the data is guarded:
+ *
+ * Foo foo TSA_GUARDED_BY(mutex);
+ */
+#define TSA_GUARDED_BY(x) TSA(guarded_by(x))
+
+/* TSA_PT_GUARDED_BY() is used to annotate global pointers, the data
+ * behind the pointer is guarded.
+ *
+ * Foo* ptr TSA_PT_GUARDED_BY(mutex);
+ */
+#define TSA_PT_GUARDED_BY(x) TSA(pt_guarded_by(x))
+
+/* The TSA_REQUIRES() is used to annotate functions: the caller of the
+ * function MUST hold the resource, the function will NOT release it.
+ *
+ * More than one mutex may be specified, comma-separated.
+ *
+ * void Foo(void) TSA_REQUIRES(mutex);
+ */
+#define TSA_REQUIRES(...) TSA(requires_capability(__VA_ARGS__))
+#define TSA_REQUIRES_SHARED(...) TSA(requires_shared_capability(__VA_ARGS__))
+
+/* TSA_EXCLUDES() is used to annotate functions: the caller of the
+ * function MUST NOT hold resource, the function first acquires the
+ * resource, and then releases it.
+ *
+ * More than one mutex may be specified, comma-separated.
+ *
+ * void Foo(void) TSA_EXCLUDES(mutex);
+ */
+#define TSA_EXCLUDES(...) TSA(locks_excluded(__VA_ARGS__))
+
+/* TSA_ACQUIRE() is used to annotate functions: the caller of the
+ * function MUST NOT hold the resource, the function will acquire the
+ * resource, but NOT release it.
+ *
+ * More than one mutex may be specified, comma-separated.
+ *
+ * void Foo(void) TSA_ACQUIRE(mutex);
+ */
+#define TSA_ACQUIRE(...) TSA(acquire_capability(__VA_ARGS__))
+#define TSA_ACQUIRE_SHARED(...) TSA(acquire_shared_capability(__VA_ARGS__))
+
+/* TSA_RELEASE() is used to annotate functions: the caller of the
+ * function MUST hold the resource, but the function will then release it.
+ *
+ * More than one mutex may be specified, comma-separated.
+ *
+ * void Foo(void) TSA_RELEASE(mutex);
+ */
+#define TSA_RELEASE(...) TSA(release_capability(__VA_ARGS__))
+#define TSA_RELEASE_SHARED(...) TSA(release_shared_capability(__VA_ARGS__))
+
+/* TSA_NO_TSA is used to annotate functions.  Use only when you need to.
+ *
+ * void Foo(void) TSA_NO_TSA;
+ */
+#define TSA_NO_TSA TSA(no_thread_safety_analysis)
+
+/*
+ * TSA_ASSERT() is used to annotate functions: This function will assert that
+ * the lock is held. When it returns, the caller of the function is assumed to
+ * already hold the resource.
+ *
+ * More than one mutex may be specified, comma-separated.
+ */
+#define TSA_ASSERT(...) TSA(assert_capability(__VA_ARGS__))
+#define TSA_ASSERT_SHARED(...) TSA(assert_shared_capability(__VA_ARGS__))
+
+#endif /* #ifndef CLANG_TSA_H */