[4/9] Add memory_region_init_ram_from_fd()

Commit Message

Marc-André Lureau April 12, 2016, 11:55 a.m. UTC

From: Marc-André Lureau <[e-mail]>

Add a new function to Initialize a RAM memory region with a mmap-ed file
descriptor.

Signed-off-by: Marc-André Lureau <[e-mail]>
---
 include/exec/memory.h | 20 ++++++++++++++++++++
 memory.c              | 16 ++++++++++++++++
 2 files changed, 36 insertions(+)

Patch

diff --git a/include/exec/memory.h b/include/exec/memory.h
index e2a3e99..017bfdd 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -399,6 +399,26 @@  void memory_region_init_ram_from_file(MemoryRegion *mr,
                                       bool share,
                                       const char *path,
                                       Error **errp);
+
+/**
+ * memory_region_init_ram_from_fd:  Initialize RAM memory region with a
+ *                                  mmap-ed backend.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: the name of the region.
+ * @size: size of the region.
+ * @share: %true if memory must be mmaped with the MAP_SHARED flag
+ * @fd: the fd to mmap.
+ * @errp: pointer to Error*, to store an error if it happens.
+ */
+void memory_region_init_ram_from_fd(MemoryRegion *mr,
+                                    struct Object *owner,
+                                    const char *name,
+                                    uint64_t size,
+                                    bool share,
+                                    int fd,
+                                    Error **errp);
 #endif
 
 /**
diff --git a/memory.c b/memory.c
index f76f85d..dad99a9 100644
--- a/memory.c
+++ b/memory.c
@@ -1351,6 +1351,22 @@  void memory_region_init_ram_from_file(MemoryRegion *mr,
     mr->ram_block = qemu_ram_alloc_from_file(size, mr, share, path, errp);
     mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
 }
+
+void memory_region_init_ram_from_fd(MemoryRegion *mr,
+                                    struct Object *owner,
+                                    const char *name,
+                                    uint64_t size,
+                                    bool share,
+                                    int fd,
+                                    Error **errp)
+{
+    memory_region_init(mr, owner, name, size);
+    mr->ram = true;
+    mr->terminates = true;
+    mr->destructor = memory_region_destructor_ram;
+    mr->ram_block = qemu_ram_alloc_from_fd(size, mr, share, fd, errp);
+    mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
+}
 #endif
 
 void memory_region_init_ram_ptr(MemoryRegion *mr,