block-coroutine-wrapper.py: support functions without bs arg

Right now, we take the first parameter of the function to get the
BlockDriverState to pass to bdrv_poll_co(), that internally calls
functions that figure in which aiocontext the coroutine should run.

However, it is useless to pass a bs just to get its own AioContext,
so instead pass it directly, and default to the main loop if no
BlockDriverState is passed as parameter.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221128142337.657646-12-eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/block-gen.h

@@ -30,7 +30,7 @@
 
 /* Base structure for argument packing structures */
 typedef struct BdrvPollCo {
-    BlockDriverState *bs;
+    AioContext *ctx;
     bool in_progress;
     int ret;
     Coroutine *co; /* Keep pointer here for debugging */
@@ -40,8 +40,8 @@ static inline int bdrv_poll_co(BdrvPollCo *s)
 {
     assert(!qemu_in_coroutine());
 
-    bdrv_coroutine_enter(s->bs, s->co);
-    BDRV_POLL_WHILE(s->bs, s->in_progress);
+    aio_co_enter(s->ctx, s->co);
+    AIO_WAIT_WHILE(s->ctx, s->in_progress);
 
     return s->ret;
 }

scripts/block-coroutine-wrapper.py

@@ -75,12 +75,14 @@ def __init__(self, return_type: str, name: str, args: str,
 
         t = self.args[0].type
         if t == 'BlockDriverState *':
-            bs = 'bs'
+            ctx = 'bdrv_get_aio_context(bs)'
         elif t == 'BdrvChild *':
-            bs = 'child->bs'
+            ctx = 'bdrv_get_aio_context(child->bs)'
+        elif t == 'BlockBackend *':
+            ctx = 'blk_get_aio_context(blk)'
         else:
-            bs = 'blk_bs(blk)'
-        self.bs = bs
+            ctx = 'qemu_get_aio_context()'
+        self.ctx = ctx
 
     def gen_list(self, format: str) -> str:
         return ', '.join(format.format_map(arg.__dict__) for arg in self.args)
@@ -127,7 +129,7 @@ def create_mixed_wrapper(func: FuncDecl) -> str:
         return {name}({ func.gen_list('{name}') });
     }} else {{
         {struct_name} s = {{
-            .poll_state.bs = {func.bs},
+            .poll_state.ctx = {func.ctx},
             .poll_state.in_progress = true,
 
 { func.gen_block('            .{name} = {name},') }
@@ -150,7 +152,7 @@ def create_co_wrapper(func: FuncDecl) -> str:
 int {func.name}({ func.gen_list('{decl}') })
 {{
     {struct_name} s = {{
-        .poll_state.bs = {func.bs},
+        .poll_state.ctx = {func.ctx},
         .poll_state.in_progress = true,
 
 { func.gen_block('        .{name} = {name},') }
@@ -166,8 +168,6 @@ def create_co_wrapper(func: FuncDecl) -> str:
 def gen_wrapper(func: FuncDecl) -> str:
     assert not '_co_' in func.name
     assert func.return_type == 'int'
-    assert func.args[0].type in ['BlockDriverState *', 'BdrvChild *',
-                                 'BlockBackend *']
 
     name = func.co_name
     struct_name = func.struct_name