Add memory_region_init_ram_from_fd()

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

Signed-off-by: Marc-André Lureau <[email protected]>
Message-Id: <20170602141229[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 80e605a96abd4053a98dc3137bbfc838df80b307..51a54c92d5f73db8783cde678af9612a21eef327 100644 (file)
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -456,6 +456,26 @@ 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 0ddc4cc28deb5d2153da67665ff9d36c0ef2f4ce..b2ace20bac981fd0b89439e4e4420e9dacd4ffe7 100644 (file)
--- a/memory.c
+++ b/memory.c
@@ -1397,6 +1397,22 @@ 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,