async: Add an optional reentrancy guard to the BH API
Devices can pass their MemoryReentrancyGuard (from their DeviceState),
when creating new BHes. Then, the async API will toggle the guard
before/after calling the BH call-back. This prevents bh->mmio reentrancy
issues.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Message-Id: <20230427211013.2994127-3-alxndr@bu.edu>
[thuth: Fix "line over 90 characters" checkpatch.pl error]
Signed-off-by: Thomas Huth <thuth@redhat.com>
diff --git a/include/block/aio.h b/include/block/aio.h
index e267d91..89bbc53 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -23,6 +23,8 @@
#include "qemu/thread.h"
#include "qemu/timer.h"
#include "block/graph-lock.h"
+#include "hw/qdev-core.h"
+
typedef struct BlockAIOCB BlockAIOCB;
typedef void BlockCompletionFunc(void *opaque, int ret);
@@ -323,9 +325,11 @@
* is opaque and must be allocated prior to its use.
*
* @name: A human-readable identifier for debugging purposes.
+ * @reentrancy_guard: A guard set when entering a cb to prevent
+ * device-reentrancy issues
*/
QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
- const char *name);
+ const char *name, MemReentrancyGuard *reentrancy_guard);
/**
* aio_bh_new: Allocate a new bottom half structure
@@ -334,7 +338,17 @@
* string.
*/
#define aio_bh_new(ctx, cb, opaque) \
- aio_bh_new_full((ctx), (cb), (opaque), (stringify(cb)))
+ aio_bh_new_full((ctx), (cb), (opaque), (stringify(cb)), NULL)
+
+/**
+ * aio_bh_new_guarded: Allocate a new bottom half structure with a
+ * reentrancy_guard
+ *
+ * A convenience wrapper for aio_bh_new_full() that uses the cb as the name
+ * string.
+ */
+#define aio_bh_new_guarded(ctx, cb, opaque, guard) \
+ aio_bh_new_full((ctx), (cb), (opaque), (stringify(cb)), guard)
/**
* aio_notify: Force processing of pending events.
