Re: [Qemu-devel] [PATCH v2 RESEND] Add skip_dump flag to ignore memory region during dump

[Paolo Bonzini <pbonzini@redhat.com>]

On 09/15/2014 05:58 AM, Nikunj A Dadhania wrote:
> The PCI MMIO might be disabled or the device in the reset state.
> Make sure we do not dump these memory regions.
> 
> Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
> Acked-by: Alex Williamson <alex.williamson@redhat.com>
> CC: Paolo Bonzini <pbonzini@redhat.com>
> ---
> 
> Resending, missed to CC Paolo
> 
> V1: 
>    * Make the flag generic in place of using vfio_mmap (Alex)
> 
>  hw/misc/vfio.c        |  1 +
>  include/exec/memory.h | 19 +++++++++++++++++++
>  memory.c              | 11 +++++++++++
>  memory_mapping.c      |  3 ++-
>  4 files changed, 33 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
> index d69bb29..c9c0398 100644
> --- a/hw/misc/vfio.c
> +++ b/hw/misc/vfio.c
> @@ -2722,6 +2722,7 @@ static int vfio_mmap_bar(VFIODevice *vdev, VFIOBAR *bar,
>          }
>  
>          memory_region_init_ram_ptr(submem, OBJECT(vdev), name, size, *map);
> +        memory_region_set_skip_dump(submem);
>      } else {
>  empty_region:
>          /* Create a zero sized sub-region to make cleanup easy. */
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index fc6e93d..2b5c1f2 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -144,6 +144,7 @@ struct MemoryRegion {
>      bool terminates;
>      bool romd_mode;
>      bool ram;
> +    bool skip_dump;
>      bool readonly; /* For RAM regions */
>      bool enabled;
>      bool rom_device;
> @@ -434,6 +435,24 @@ uint64_t memory_region_size(MemoryRegion *mr);
>  bool memory_region_is_ram(MemoryRegion *mr);
>  
>  /**
> + * memory_region_is_skip_dump: check whether a memory region should not be
> + *                             dumped
> + *
> + * Returns %true is a memory region should not be dumped(e.g. VFIO BAR MMAP).
> + *
> + * @mr: the memory region being queried
> + */
> +bool memory_region_is_skip_dump(MemoryRegion *mr);
> +
> +/**
> + * memory_region_set_skip_dump: Set skip_dump flag, dump will ignore this memory
> + *                              region
> + *
> + * @mr: the memory region being queried
> + */
> +void memory_region_set_skip_dump(MemoryRegion *mr);
> +
> +/**
>   * memory_region_is_romd: check whether a memory region is in ROMD mode
>   *
>   * Returns %true if a memory region is a ROM device and currently set to allow
> diff --git a/memory.c b/memory.c
> index 664d3e6..cbd8cad 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -847,6 +847,7 @@ void memory_region_init(MemoryRegion *mr,
>      mr->enabled = true;
>      mr->terminates = false;
>      mr->ram = false;
> +    mr->skip_dump = false;
>      mr->romd_mode = true;
>      mr->readonly = false;
>      mr->rom_device = false;

This hunk is not needed anymore; removed and applied, thanks.

Paolo

> @@ -1032,6 +1033,11 @@ void memory_region_init_ram_ptr(MemoryRegion *mr,
>      mr->ram_addr = qemu_ram_alloc_from_ptr(size, ptr, mr);
>  }
>  
> +void memory_region_set_skip_dump(MemoryRegion *mr)
> +{
> +    mr->skip_dump = true;
> +}
> +
>  void memory_region_init_alias(MemoryRegion *mr,
>                                Object *owner,
>                                const char *name,
> @@ -1129,6 +1135,11 @@ bool memory_region_is_ram(MemoryRegion *mr)
>      return mr->ram;
>  }
>  
> +bool memory_region_is_skip_dump(MemoryRegion *mr)
> +{
> +    return mr->skip_dump;
> +}
> +
>  bool memory_region_is_logging(MemoryRegion *mr)
>  {
>      return mr->dirty_log_mask;
> diff --git a/memory_mapping.c b/memory_mapping.c
> index 87a6ed5..7b69801 100644
> --- a/memory_mapping.c
> +++ b/memory_mapping.c
> @@ -203,7 +203,8 @@ static void guest_phys_blocks_region_add(MemoryListener *listener,
>      GuestPhysBlock *predecessor;
>  
>      /* we only care about RAM */
> -    if (!memory_region_is_ram(section->mr)) {
> +    if (!memory_region_is_ram(section->mr) ||
> +        memory_region_is_skip_dump(section->mr)) {
>          return;
>      }
>  
>