1 files changed, 45 insertions, 10 deletions

diff --git a/softmmu/physmem.c b/softmmu/physmem.c
index 43ae70f..4e1b27a 100644
--- a/softmmu/physmem.c
+++ b/softmmu/physmem.c
@@ -42,6 +42,7 @@
 #include "qemu/config-file.h"
 #include "qemu/error-report.h"
 #include "qemu/qemu-print.h"
+#include "qemu/log.h"
 #include "qemu/memalign.h"
 #include "exec/memory.h"
 #include "exec/ioport.h"
@@ -2760,6 +2761,33 @@ static bool prepare_mmio_access(MemoryRegion *mr)
     return release_lock;
 }
 
+/**
+ * flatview_access_allowed
+ * @mr: #MemoryRegion to be accessed
+ * @attrs: memory transaction attributes
+ * @addr: address within that memory region
+ * @len: the number of bytes to access
+ *
+ * Check if a memory transaction is allowed.
+ *
+ * Returns: true if transaction is allowed, false if denied.
+ */
+static bool flatview_access_allowed(MemoryRegion *mr, MemTxAttrs attrs,
+                                    hwaddr addr, hwaddr len)
+{
+    if (likely(!attrs.memory)) {
+        return true;
+    }
+    if (memory_region_is_ram(mr)) {
+        return true;
+    }
+    qemu_log_mask(LOG_GUEST_ERROR,
+                  "Invalid access to non-RAM device at "
+                  "addr 0x%" HWADDR_PRIX ", size %" HWADDR_PRIu ", "
+                  "region '%s'\n", addr, len, memory_region_name(mr));
+    return false;
+}
+
 /* Called within RCU critical section.  */
 static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr,
                                            MemTxAttrs attrs,
@@ -2774,7 +2802,10 @@ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr,
     const uint8_t *buf = ptr;
 
     for (;;) {
-        if (!memory_access_is_direct(mr, true)) {
+        if (!flatview_access_allowed(mr, attrs, addr1, l)) {
+            result |= MEMTX_ACCESS_ERROR;
+            /* Keep going. */
+        } else if (!memory_access_is_direct(mr, true)) {
             release_lock |= prepare_mmio_access(mr);
             l = memory_access_size(mr, l, addr1);
             /* XXX: could force current_cpu to NULL to avoid
@@ -2816,14 +2847,14 @@ static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
     hwaddr l;
     hwaddr addr1;
     MemoryRegion *mr;
-    MemTxResult result = MEMTX_OK;
 
     l = len;
     mr = flatview_translate(fv, addr, &addr1, &l, true, attrs);
-    result = flatview_write_continue(fv, addr, attrs, buf, len,
-                                     addr1, l, mr);
-
-    return result;
+    if (!flatview_access_allowed(mr, attrs, addr, len)) {
+        return MEMTX_ACCESS_ERROR;
+    }
+    return flatview_write_continue(fv, addr, attrs, buf, len,
+                                   addr1, l, mr);
 }
 
 /* Called within RCU critical section.  */
@@ -2840,7 +2871,10 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
 
     fuzz_dma_read_cb(addr, len, mr);
     for (;;) {
-        if (!memory_access_is_direct(mr, false)) {
+        if (!flatview_access_allowed(mr, attrs, addr1, l)) {
+            result |= MEMTX_ACCESS_ERROR;
+            /* Keep going. */
+        } else if (!memory_access_is_direct(mr, false)) {
             /* I/O case */
             release_lock |= prepare_mmio_access(mr);
             l = memory_access_size(mr, l, addr1);
@@ -2883,6 +2917,9 @@ static MemTxResult flatview_read(FlatView *fv, hwaddr addr,
 
     l = len;
     mr = flatview_translate(fv, addr, &addr1, &l, false, attrs);
+    if (!flatview_access_allowed(mr, attrs, addr, len)) {
+        return MEMTX_ACCESS_ERROR;
+    }
     return flatview_read_continue(fv, addr, attrs, buf, len,
                                   addr1, l, mr);
 }
@@ -3139,12 +3176,10 @@ bool address_space_access_valid(AddressSpace *as, hwaddr addr,
                                 MemTxAttrs attrs)
 {
     FlatView *fv;
-    bool result;
 
     RCU_READ_LOCK_GUARD();
     fv = address_space_to_flatview(as);
-    result = flatview_access_valid(fv, addr, len, is_write, attrs);
-    return result;
+    return flatview_access_valid(fv, addr, len, is_write, attrs);
 }
 
 static hwaddr