[PATCH] softmmu/memory: Log invalid memory accesses

[Philippe Mathieu-Daudé]

Log invalid memory accesses with as GUEST_ERROR.

This is particularly useful since commit 5d971f9e67 which reverted
("memory: accept mismatching sizes in memory_region_access_valid").

Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com>
---
 softmmu/memory.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/softmmu/memory.c b/softmmu/memory.c
index fa280a19f7..403ff3abc9 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -14,6 +14,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/log.h"
 #include "qapi/error.h"
 #include "cpu.h"
 #include "exec/memory.h"
@@ -1353,10 +1354,18 @@ bool memory_region_access_valid(MemoryRegion *mr,
 {
     if (mr->ops->valid.accepts
         && !mr->ops->valid.accepts(mr->opaque, addr, size, is_write, attrs)) {
+        qemu_log_mask(LOG_GUEST_ERROR, "Invalid access at addr "
+                                       "0x%" HWADDR_PRIX ", size %u, "
+                                       "region '%s', reason: rejected\n",
+                      addr, size, memory_region_name(mr));
         return false;
     }
 
     if (!mr->ops->valid.unaligned && (addr & (size - 1))) {
+        qemu_log_mask(LOG_GUEST_ERROR, "Invalid access at addr "
+                                       "0x%" HWADDR_PRIX ", size %u, "
+                                       "region '%s', reason: unaligned\n",
+                      addr, size, memory_region_name(mr));
         return false;
     }
 
@@ -1367,6 +1376,13 @@ bool memory_region_access_valid(MemoryRegion *mr,
 
     if (size > mr->ops->valid.max_access_size
         || size < mr->ops->valid.min_access_size) {
+        qemu_log_mask(LOG_GUEST_ERROR, "Invalid access at addr "
+                                       "0x%" HWADDR_PRIX ", size %u, "
+                                       "region '%s', reason: invalid size "
+                                       "(min:%u max:%u)\n",
+                      addr, size, memory_region_name(mr),
+                      mr->ops->valid.min_access_size,
+                      mr->ops->valid.max_access_size);
         return false;
     }
     return true;
-- 
2.26.2