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

[Pankaj Gupta <pagupta@redhat.com>]

> 
> From: Zhang Yi <yi.z.zhang@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.zhang@intel.com>
> Signed-off-by: Zhang Yi <yi.z.zhang@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

Looks good to me.

Reviewed-by: pagupta@redhat.com

> 
> 
>