[Qemu-devel] [PATCH v11 1/3] util/mmap-alloc: Add a 'is_pmem' parameter to qemu_ram_mmap

[Zhang, Yi]

From: Zhang Yi <yi.z.zh...@linux.intel.com>

besides the existing 'shared' flags, we are going to add
'is_pmem' to qemu_ram_mmap(), which indicated the memory backend
file is a persist memory.

Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com>
Signed-off-by: Zhang Yi <yi.z.zh...@linux.intel.com>
---
 exec.c                    |  2 +-
 include/qemu/mmap-alloc.h | 21 ++++++++++++++++++++-
 util/mmap-alloc.c         |  6 +++++-
 util/oslib-posix.c        |  2 +-
 4 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/exec.c b/exec.c
index bb6170d..27cea52 100644
--- a/exec.c
+++ b/exec.c
@@ -1860,7 +1860,7 @@ static void *file_ram_alloc(RAMBlock *block,
     }
 
     area = qemu_ram_mmap(fd, memory, block->mr->align,
-                         block->flags & RAM_SHARED);
+                         block->flags & RAM_SHARED, block->flags & RAM_PMEM);
     if (area == MAP_FAILED) {
         error_setg_errno(errp, errno,
                          "unable to map backing store for guest RAM");
diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h
index 50385e3..190688a 100644
--- a/include/qemu/mmap-alloc.h
+++ b/include/qemu/mmap-alloc.h
@@ -7,7 +7,26 @@ size_t qemu_fd_getpagesize(int fd);
 
 size_t qemu_mempath_getpagesize(const char *mem_path);
 
-void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared);
+/**
+ * qemu_ram_mmap: mmap the specified file or device.
+ *
+ * Parameters:
+ *  @fd: the file or the device to mmap
+ *  @size: the number of bytes to be mmaped
+ *  @align: if not zero, specify the alignment of the starting mapping address;
+ *          otherwise, the alignment in use will be determined by QEMU.
+ *  @shared: map has RAM_SHARED flag.
+ *  @is_pmem: map has RAM_PMEM flag.
+ *
+ * Return:
+ *  On success, return a pointer to the mapped area.
+ *  On failure, return MAP_FAILED.
+ */
+void *qemu_ram_mmap(int fd,
+                    size_t size,
+                    size_t align,
+                    bool shared,
+                    bool is_pmem);
 
 void qemu_ram_munmap(void *ptr, size_t size);
 
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index fd329ec..97bbeed 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -75,7 +75,11 @@ size_t qemu_mempath_getpagesize(const char *mem_path)
     return getpagesize();
 }
 
-void *qemu_ram_mmap(int fd, size_t size, size_t align, bool shared)
+void *qemu_ram_mmap(int fd,
+                    size_t size,
+                    size_t align,
+                    bool shared,
+                    bool is_pmem)
 {
     /*
      * Note: this always allocates at least one extra page of virtual address
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index fbd0dc8..040937f 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -203,7 +203,7 @@ void *qemu_memalign(size_t alignment, size_t size)
 void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment, bool shared)
 {
     size_t align = QEMU_VMALLOC_ALIGN;
-    void *ptr = qemu_ram_mmap(-1, size, align, shared);
+    void *ptr = qemu_ram_mmap(-1, size, align, shared, false);
 
     if (ptr == MAP_FAILED) {
         return NULL;
-- 
2.7.4