An read only file can be mapped with read write as long as the mapping is private, which is very common case. Make qemu_ram_alloc_from_file open file as read only when the mapping is private, otherwise open will fail when file does not allow write.
If this file does not exist or is a directory, the flag is not used, so it should be OK. from https://gitlab.com/qemu-project/qemu/-/issues/1689 Signed-off-by: Thiner Logoer <logoerthin...@163.com> --- softmmu/physmem.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/softmmu/physmem.c b/softmmu/physmem.c index 3df73542e1..e8036ee335 100644 --- a/softmmu/physmem.c +++ b/softmmu/physmem.c @@ -1945,8 +1945,15 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, int fd; bool created; RAMBlock *block; + + /* + * If map is private, the fd does not need to be writable. + * This only get effective when the file is existent. + */ + bool open_as_readonly = readonly || !(ram_flags & RAM_SHARED); - fd = file_ram_open(mem_path, memory_region_name(mr), readonly, &created, + fd = file_ram_open(mem_path, memory_region_name(mr), + open_as_readonly, &created, errp); if (fd < 0) { return NULL; -- 2.40.1
