From: CJ Chen <cjchen@igel.co.jp>

When it comes to this pattern: .valid.unaligned = false and
impl.unaligned = true, is effectlvely contradictory. The .valid
structure indicates that unaligned access should be rejected at
the access validation phase, yet .impl suggests the underlying
device implementation can handle unaligned operations. As a result,
the upper-layer code will never even reach the .impl logic.

Add an assertion that the MemoryRegionOps doesn't specify
this invalid combination.

Signed-off-by: CJ Chen <cjchen@igel.co.jp>
Tested-by: CJ Chen <cjchen@igel.co.jp>
Suggested-by: Peter Xu <peterx@redhat.com>
Acked-by: Tomoyuki Hirose <hrstmyk811m@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
[PMM: tweaked commit message]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Link: https://lore.kernel.org/r/20260428093339.2087081-5-peter.maydell@linaro.org
Signed-off-by: Peter Xu <peterx@redhat.com>
---
 system/memory.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/system/memory.c b/system/memory.c
index 225bbe38c3..739ba11da6 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -1573,6 +1573,7 @@ void memory_region_init_io(MemoryRegion *mr, Object *owner,
                            const MemoryRegionOps *ops, void *opaque,
                            const char *name, uint64_t size)
 {
+    g_assert(!ops || !(ops->impl.unaligned && !ops->valid.unaligned));
     memory_region_init(mr, owner, name, size);
     memory_region_set_ops(mr, ops, opaque);
 }
-- 
2.53.0