[Qemu-devel] [PATCH v2 RESEND] Add skip_dump flag to ignore memory region during dump

[Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>]

The PCI MMIO might be disabled or the device in the reset state.
Make sure we do not dump these memory regions.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
CC: Paolo Bonzini <pbonzini@redhat.com>
---

Resending, missed to CC Paolo

V1: 
   * Make the flag generic in place of using vfio_mmap (Alex)

 hw/misc/vfio.c        |  1 +
 include/exec/memory.h | 19 +++++++++++++++++++
 memory.c              | 11 +++++++++++
 memory_mapping.c      |  3 ++-
 4 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index d69bb29..c9c0398 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -2722,6 +2722,7 @@ static int vfio_mmap_bar(VFIODevice *vdev, VFIOBAR *bar,
         }
 
         memory_region_init_ram_ptr(submem, OBJECT(vdev), name, size, *map);
+        memory_region_set_skip_dump(submem);
     } else {
 empty_region:
         /* Create a zero sized sub-region to make cleanup easy. */
diff --git a/include/exec/memory.h b/include/exec/memory.h
index fc6e93d..2b5c1f2 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -144,6 +144,7 @@ struct MemoryRegion {
     bool terminates;
     bool romd_mode;
     bool ram;
+    bool skip_dump;
     bool readonly; /* For RAM regions */
     bool enabled;
     bool rom_device;
@@ -434,6 +435,24 @@ uint64_t memory_region_size(MemoryRegion *mr);
 bool memory_region_is_ram(MemoryRegion *mr);
 
 /**
+ * memory_region_is_skip_dump: check whether a memory region should not be
+ *                             dumped
+ *
+ * Returns %true is a memory region should not be dumped(e.g. VFIO BAR MMAP).
+ *
+ * @mr: the memory region being queried
+ */
+bool memory_region_is_skip_dump(MemoryRegion *mr);
+
+/**
+ * memory_region_set_skip_dump: Set skip_dump flag, dump will ignore this memory
+ *                              region
+ *
+ * @mr: the memory region being queried
+ */
+void memory_region_set_skip_dump(MemoryRegion *mr);
+
+/**
  * memory_region_is_romd: check whether a memory region is in ROMD mode
  *
  * Returns %true if a memory region is a ROM device and currently set to allow
diff --git a/memory.c b/memory.c
index 664d3e6..cbd8cad 100644
--- a/memory.c
+++ b/memory.c
@@ -847,6 +847,7 @@ void memory_region_init(MemoryRegion *mr,
     mr->enabled = true;
     mr->terminates = false;
     mr->ram = false;
+    mr->skip_dump = false;
     mr->romd_mode = true;
     mr->readonly = false;
     mr->rom_device = false;
@@ -1032,6 +1033,11 @@ void memory_region_init_ram_ptr(MemoryRegion *mr,
     mr->ram_addr = qemu_ram_alloc_from_ptr(size, ptr, mr);
 }
 
+void memory_region_set_skip_dump(MemoryRegion *mr)
+{
+    mr->skip_dump = true;
+}
+
 void memory_region_init_alias(MemoryRegion *mr,
                               Object *owner,
                               const char *name,
@@ -1129,6 +1135,11 @@ bool memory_region_is_ram(MemoryRegion *mr)
     return mr->ram;
 }
 
+bool memory_region_is_skip_dump(MemoryRegion *mr)
+{
+    return mr->skip_dump;
+}
+
 bool memory_region_is_logging(MemoryRegion *mr)
 {
     return mr->dirty_log_mask;
diff --git a/memory_mapping.c b/memory_mapping.c
index 87a6ed5..7b69801 100644
--- a/memory_mapping.c
+++ b/memory_mapping.c
@@ -203,7 +203,8 @@ static void guest_phys_blocks_region_add(MemoryListener *listener,
     GuestPhysBlock *predecessor;
 
     /* we only care about RAM */
-    if (!memory_region_is_ram(section->mr)) {
+    if (!memory_region_is_ram(section->mr) ||
+        memory_region_is_skip_dump(section->mr)) {
         return;
     }
 
-- 
1.8.3.1