Re: [PATCH v5 1/3] memory: drop guest writes to read-only ram device regions

[Philippe Mathieu-Daudé]

On 4/30/20 7:19 AM, Yan Zhao wrote:

for ram device regions, drop guest writes if the regions is read-only.

Cc: Philippe Mathieu-Daudé <phi...@redhat.com>
Signed-off-by: Yan Zhao <yan.y.z...@intel.com>
Signed-off-by: Xin Zeng <xin.z...@intel.com>
---
  memory.c | 15 ++++++++++++---
  1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/memory.c b/memory.c
index 601b749906..90a748912f 100644
--- a/memory.c
+++ b/memory.c
@@ -34,6 +34,7 @@
  #include "sysemu/accel.h"
  #include "hw/boards.h"
  #include "migration/vmstate.h"
+#include "qemu/log.h"

//#define DEBUG_UNASSIGNED @@ -1307,12 +1308,19 @@ static uint64_t memory_region_ram_device_read(void *opaque,

      return data;
  }

-static void memory_region_ram_device_write(void *opaque, hwaddr addr,

-                                           uint64_t data, unsigned size)
+static MemTxResult memory_region_ram_device_write(void *opaque, hwaddr addr,
+                                           uint64_t data, unsigned size,
+                                           MemTxAttrs attrs)

Style alignment is now of and can be adjusted easily.

  {
      MemoryRegion *mr = opaque;

trace_memory_region_ram_device_write(get_cpu_index(), mr, addr, data, size);

+    if (mr->readonly) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "Invalid write to read only ram device region addr 0x%"
+                       HWADDR_PRIx" size %u\n", addr, size);

Style alignment of here too.

Otherwise:
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>

+        return MEMTX_ERROR;
+    }

switch (size) {

      case 1:
@@ -1328,11 +1336,12 @@ static void memory_region_ram_device_write(void 
*opaque, hwaddr addr,
          *(uint64_t *)(mr->ram_block->host + addr) = data;
          break;
      }
+    return MEMTX_OK;
  }

static const MemoryRegionOps ram_device_mem_ops = {

      .read = memory_region_ram_device_read,
-    .write = memory_region_ram_device_write,
+    .write_with_attrs = memory_region_ram_device_write,
      .endianness = DEVICE_HOST_ENDIAN,
      .valid = {
          .min_access_size = 1,