As more flag parameters besides the existing 'shared' are going to be
added to qemu_ram_mmap(), let's switch 'shared' to a 'flags' parameter
in advance, so as to ease the further additions.
Signed-off-by: Haozhong Zhang <haozhong.zh...@intel.com>
Suggested-by: "Michael S. Tsirkin" <m...@redhat.com>
---
exec.c | 2 +-
include/exec/memory.h | 3 +++
include/qemu/mmap-alloc.h | 19 ++++++++++++++++++-
util/mmap-alloc.c | 8 +++++---
util/oslib-posix.c | 2 +-
5 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/exec.c b/exec.c
index 629a508385..c0a5a52c4a 100644
--- a/exec.c
+++ b/exec.c
@@ -1653,7 +1653,7 @@ static void *file_ram_alloc(RAMBlock *block,
}
area = qemu_ram_mmap(fd, memory, block->mr->align,
- block->flags & RAM_SHARED);
+ (block->flags & RAM_SHARED) ? QEMU_RAM_SHARE : 0);
if (area == MAP_FAILED) {
error_setg_errno(errp, errno,
"unable to map backing store for guest RAM");
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 07c5d6d597..4790cd9e13 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -455,6 +455,9 @@ void memory_region_init_resizeable_ram(MemoryRegion *mr,
uint64_t length,
void *host),
Error **errp);
+
+#define QEMU_RAM_SHARE (1UL << 0)
+
#ifdef __linux__
/**
* memory_region_init_ram_from_file: Initialize RAM memory region with a
diff --git a/include/qemu/mmap-alloc.h b/include/qemu/mmap-alloc.h
index 50385e3f81..dc5e8b5efb 100644
--- a/include/qemu/mmap-alloc.h
+++ b/include/qemu/mmap-alloc.h
@@ -7,7 +7,24 @@ 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.
+ * @flags: specifies additional properties of the mapping, which can be one or
+ * bit-or of following values
+ * - QEMU_RAM_SHARE: mmap with MAP_SHARED flag
+ * Other bits are ignored.
+ *
+ * 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, uint64_t flags);
void qemu_ram_munmap(void *ptr, size_t size);
diff --git a/util/mmap-alloc.c b/util/mmap-alloc.c
index 2fd8cbcc6f..cd95566800 100644
--- a/util/mmap-alloc.c
+++ b/util/mmap-alloc.c
@@ -13,6 +13,7 @@
#include "qemu/osdep.h"
#include "qemu/mmap-alloc.h"
#include "qemu/host-utils.h"
+#include "exec/memory.h"
#define HUGETLBFS_MAGIC 0x958458f6
@@ -73,7 +74,7 @@ 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, uint64_t flags)
{
/*
* Note: this always allocates at least one extra page of virtual address
@@ -90,11 +91,12 @@ void *qemu_ram_mmap(int fd, size_t size, size_t align, bool
shared)
* anonymous memory is OK.
*/
int anonfd = fd == -1 || qemu_fd_getpagesize(fd) == getpagesize() ? -1 :
fd;
- int flags = anonfd == -1 ? MAP_ANONYMOUS : MAP_NORESERVE;
- void *ptr = mmap(0, total, PROT_NONE, flags | MAP_PRIVATE, anonfd, 0);
+ int mmap_flags = anonfd == -1 ? MAP_ANONYMOUS : MAP_NORESERVE;
+ void *ptr = mmap(0, total, PROT_NONE, mmap_flags | MAP_PRIVATE, anonfd, 0);
#else
void *ptr = mmap(0, total, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
#endif
+ bool shared = flags & QEMU_RAM_SHARE;
size_t offset;
void *ptr1;
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 77369c92ce..2a78cfb67e 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -130,7 +130,7 @@ void *qemu_memalign(size_t alignment, size_t size)
void *qemu_anon_ram_alloc(size_t size, uint64_t *alignment)
{
size_t align = QEMU_VMALLOC_ALIGN;
- void *ptr = qemu_ram_mmap(-1, size, align, false);
+ void *ptr = qemu_ram_mmap(-1, size, align, 0);
if (ptr == MAP_FAILED) {
return NULL;
--
2.14.1
