[Qemu-devel] [PATCH v3 1/8] memory, exec: switch file ram allocation functions to 'flags' parameters

[Haozhong Zhang <haozhong.zhang@intel.com>]

As more flag parameters besides the existing 'share' are going to be
added to following functions
    memory_region_init_ram_from_file
    qemu_ram_alloc_from_fd
    qemu_ram_alloc_from_file
, let's switch them to use the 'flags' parameters so as to ease future
flag additions.

The existing 'share' flag is converted to the QEMU_RAM_SHARE bit in
flags, and other flag bits are ignored by above functions right now.

Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
---
 backends/hostmem-file.c |  3 ++-
 exec.c                  |  7 ++++---
 include/exec/memory.h   | 10 ++++++++--
 include/exec/ram_addr.h | 25 +++++++++++++++++++++++--
 memory.c                |  8 +++++---
 numa.c                  |  2 +-
 6 files changed, 43 insertions(+), 12 deletions(-)

diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
index 134b08d63a..30df843d90 100644
--- a/backends/hostmem-file.c
+++ b/backends/hostmem-file.c
@@ -58,7 +58,8 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
         path = object_get_canonical_path(OBJECT(backend));
         memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
                                  path,
-                                 backend->size, fb->align, backend->share,
+                                 backend->size, fb->align,
+                                 backend->share ? QEMU_RAM_SHARE : 0,
                                  fb->mem_path, errp);
         g_free(path);
     }
diff --git a/exec.c b/exec.c
index 4d8addb263..537bf12412 100644
--- a/exec.c
+++ b/exec.c
@@ -2000,12 +2000,13 @@ static void ram_block_add(RAMBlock *new_block, Error **errp, bool shared)
 
 #ifdef __linux__
 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
-                                 bool share, int fd,
+                                 uint64_t flags, int fd,
                                  Error **errp)
 {
     RAMBlock *new_block;
     Error *local_err = NULL;
     int64_t file_size;
+    bool share = flags & QEMU_RAM_SHARE;
 
     if (xen_enabled()) {
         error_setg(errp, "-mem-path not supported with Xen");
@@ -2061,7 +2062,7 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
 
 
 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
-                                   bool share, const char *mem_path,
+                                   uint64_t flags, const char *mem_path,
                                    Error **errp)
 {
     int fd;
@@ -2073,7 +2074,7 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
         return NULL;
     }
 
-    block = qemu_ram_alloc_from_fd(size, mr, share, fd, errp);
+    block = qemu_ram_alloc_from_fd(size, mr, flags, fd, errp);
     if (!block) {
         if (created) {
             unlink(mem_path);
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 15e81113ba..0fc9d23a48 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -487,6 +487,9 @@ void memory_region_init_resizeable_ram(MemoryRegion *mr,
                                                        void *host),
                                        Error **errp);
 #ifdef __linux__
+
+#define QEMU_RAM_SHARE      (1UL << 0)
+
 /**
  * memory_region_init_ram_from_file:  Initialize RAM memory region with a
  *                                    mmap-ed backend.
@@ -498,7 +501,10 @@ void memory_region_init_resizeable_ram(MemoryRegion *mr,
  * @size: size of the region.
  * @align: alignment of the region base address; if 0, the default alignment
  *         (getpagesize()) will be used.
- * @share: %true if memory must be mmaped with the MAP_SHARED flag
+ * @flags: specify properties of this memory region, which can be one or bit-or
+ *         of following values:
+ *         - QEMU_RAM_SHARE: memory must be mmaped with the MAP_SHARED flag
+ *         Other bits are ignored.
  * @path: the path in which to allocate the RAM.
  * @errp: pointer to Error*, to store an error if it happens.
  *
@@ -510,7 +516,7 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
                                       const char *name,
                                       uint64_t size,
                                       uint64_t align,
-                                      bool share,
+                                      uint64_t flags,
                                       const char *path,
                                       Error **errp);
 
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index cf2446a176..b8b01d1eb9 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -72,12 +72,33 @@ static inline unsigned long int ramblock_recv_bitmap_offset(void *host_addr,
 
 long qemu_getrampagesize(void);
 unsigned long last_ram_page(void);
+
+/**
+ * qemu_ram_alloc_from_file,
+ * qemu_ram_alloc_from_fd:  Allocate a ram block from the specified back
+ *                          file or device
+ *
+ * Parameters:
+ *  @size: the size in bytes of the ram block
+ *  @mr: the memory region where the ram block is
+ *  @flags: specify the properties of the ram block, which can be one
+ *          or bit-or of following values
+ *          - QEMU_RAM_SHARE: mmap the back file or device with MAP_SHARED
+ *          Other bits are ignored.
+ *  @mem_path or @fd: specify the back file or device
+ *  @errp: pointer to Error*, to store an error if it happens
+ *
+ * Return:
+ *  On success, return a pointer to the ram block.
+ *  On failure, return NULL.
+ */
 RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
-                                   bool share, const char *mem_path,
+                                   uint64_t flags, const char *mem_path,
                                    Error **errp);
 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
-                                 bool share, int fd,
+                                 uint64_t flags, int fd,
                                  Error **errp);
+
 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
                                   MemoryRegion *mr, Error **errp);
 RAMBlock *qemu_ram_alloc(ram_addr_t size, bool share, MemoryRegion *mr,
diff --git a/memory.c b/memory.c
index 6515131ac2..e89500837a 100644
--- a/memory.c
+++ b/memory.c
@@ -1582,7 +1582,7 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
                                       const char *name,
                                       uint64_t size,
                                       uint64_t align,
-                                      bool share,
+                                      uint64_t flags,
                                       const char *path,
                                       Error **errp)
 {
@@ -1591,7 +1591,7 @@ void memory_region_init_ram_from_file(MemoryRegion *mr,
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram;
     mr->align = align;
-    mr->ram_block = qemu_ram_alloc_from_file(size, mr, share, path, errp);
+    mr->ram_block = qemu_ram_alloc_from_file(size, mr, flags, path, errp);
     mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
 }
 
@@ -1607,7 +1607,9 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr,
     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->ram_block = qemu_ram_alloc_from_fd(size, mr,
+                                           share ? QEMU_RAM_SHARE : 0,
+                                           fd, errp);
     mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
 }
 #endif
diff --git a/numa.c b/numa.c
index 7e0e789b02..ff5a0bbe18 100644
--- a/numa.c
+++ b/numa.c
@@ -457,7 +457,7 @@ static void allocate_system_memory_nonnuma(MemoryRegion *mr, Object *owner,
     if (mem_path) {
 #ifdef __linux__
         Error *err = NULL;
-        memory_region_init_ram_from_file(mr, owner, name, ram_size, 0, false,
+        memory_region_init_ram_from_file(mr, owner, name, ram_size, 0, 0,
                                          mem_path, &err);
         if (err) {
             error_report_err(err);
-- 
2.16.1