softmmu/memory: Log invalid memory accesses

Log invalid memory accesses with as GUEST_ERROR.

This is particularly useful since commit 5d971f9e which reverted
("memory: accept mismatching sizes in memory_region_access_valid").

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20201005152725.2143444-1-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

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;