monitor: Use address_space_read() to read memory

Currently monitor.c reads physical memory using
cpu_physical_memory_read(). This effectively hard-codes
assuming that all CPUs have the same view of physical
memory. Switch to address_space_read() instead, which
lets us use the AddressSpace for the CPU we're
reading memory for (falling back to address_space_memory
if there is no CPU, as happens with the "none" board).
As a bonus, this allows us to detect failures to read memory.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20181122172653.3413-3-peter.maydell@linaro.org

monitor.c

@@ -1605,7 +1605,13 @@ static void memory_dump(Monitor *mon, int count, int format, int wsize,
         if (l > line_size)
             l = line_size;
         if (is_physical) {
-            cpu_physical_memory_read(addr, buf, l);
+            AddressSpace *as = cs ? cs->as : &address_space_memory;
+            MemTxResult r = address_space_read(as, addr,
+                                               MEMTXATTRS_UNSPECIFIED, buf, l);
+            if (r != MEMTX_OK) {
+                monitor_printf(mon, " Cannot access memory\n");
+                break;
+            }
         } else {
             if (cpu_memory_rw_debug(cs, addr, buf, l, 0) < 0) {
                 monitor_printf(mon, " Cannot access memory\n");