memory: differentiate memory_region_is_logging and memory_region_get_dirty_log_mask

For now memory regions only track DIRTY_MEMORY_VGA individually, but
this will change soon.  To support this, split memory_region_is_logging
in two functions: one that returns a given bit from dirty_log_mask,
and one that returns the entire mask.  memory_region_is_logging gets an
extra parameter so that the compiler flags misuse.

While VGA-specific users (including the Xen listener!) will want to keep
checking that bit, KVM and vhost check for "any bit except migration"
(because migration is handled via the global start/stop listener
callbacks).

Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 7b0929d54f..156d506063 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -591,11 +591,23 @@ const char *memory_region_name(const MemoryRegion *mr);
 /**
  * memory_region_is_logging: return whether a memory region is logging writes
  *
- * Returns %true if the memory region is logging writes
+ * Returns %true if the memory region is logging writes for the given client
  *
  * @mr: the memory region being queried
+ * @client: the client being queried
  */
-bool memory_region_is_logging(MemoryRegion *mr);
+bool memory_region_is_logging(MemoryRegion *mr, uint8_t client);
+
+/**
+ * memory_region_get_dirty_log_mask: return the clients for which a
+ * memory region is logging writes.
+ *
+ * Returns a bitmap of clients, which right now will be either 0 or
+ * (1 << DIRTY_MEMORY_VGA).
+ *
+ * @mr: the memory region being queried
+ */
+uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr);
 
 /**
  * memory_region_is_rom: check whether a memory region is ROM