Re: [Qemu-devel] [PATCH V9 2/6] memory: use sparse feature define RAM_FLAG.

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jan 16, 2019 at 04:10:29PM +0800, Zhang Yi wrote:
> Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

OK so if you apply this patch, do you get
any sparse warning at all?

If not how come?

And we need to ask patchew maintainers to 

Overall I'd suggest that since you no longer need
a new RAM flag, split this effort out and finish
MAP_SYNC work first.


> ---
>  include/exec/memory.h | 12 ++++++------
>  include/qemu/osdep.h  |  9 +++++++++
>  2 files changed, 15 insertions(+), 6 deletions(-)
> 
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index 667466b..03824d9 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -104,27 +104,27 @@ struct IOMMUNotifier {
>  typedef struct IOMMUNotifier IOMMUNotifier;
>  
>  /* RAM is pre-allocated and passed into qemu_ram_alloc_from_ptr */
> -#define RAM_PREALLOC   (1 << 0)
> +#define RAM_PREALLOC ((QEMU_FORCE QemuMmapFlags) (1 << 0))
>  
>  /* RAM is mmap-ed with MAP_SHARED */
> -#define RAM_SHARED     (1 << 1)
> +#define RAM_SHARED ((QEMU_FORCE QemuMmapFlags) (1 << 1))
>  
>  /* Only a portion of RAM (used_length) is actually used, and migrated.
>   * This used_length size can change across reboots.
>   */
> -#define RAM_RESIZEABLE (1 << 2)
> +#define RAM_RESIZEABLE ((QEMU_FORCE QemuMmapFlags) (1 << 2))
>  
>  /* UFFDIO_ZEROPAGE is available on this RAMBlock to atomically
>   * zero the page and wake waiting processes.
>   * (Set during postcopy)
>   */
> -#define RAM_UF_ZEROPAGE (1 << 3)
> +#define RAM_UF_ZEROPAGE ((QEMU_FORCE QemuMmapFlags) (1 << 3))
>  
>  /* RAM can be migrated */
> -#define RAM_MIGRATABLE (1 << 4)
> +#define RAM_MIGRATABLE ((QEMU_FORCE QemuMmapFlags) (1 << 4))
>  
>  /* RAM is a persistent kind memory */
> -#define RAM_PMEM (1 << 5)
> +#define RAM_PMEM ((QEMU_FORCE QemuMmapFlags) (1 << 5))
>  
>  static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
>                                         IOMMUNotifierFlag flags,
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index 3bf48bc..457d24e 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -185,6 +185,15 @@ extern int daemon(int, int);
>  #define ESHUTDOWN 4099
>  #endif
>  
> +#ifdef __CHECKER__
> +#define QEMU_BITWISE __attribute__((bitwise))
> +#define QEMU_FORCE   __attribute__((force))
> +#else
> +#define QEMU_BITWISE
> +#define QEMU_FORCE
> +#endif
> +
> +typedef unsigned QEMU_BITWISE QemuMmapFlags;
>  /* time_t may be either 32 or 64 bits depending on the host OS, and
>   * can be either signed or unsigned, so we can't just hardcode a
>   * specific maximum value. This is not a C preprocessor constant,
> -- 
> 2.7.4