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

[Alexander Graf <agraf@suse.de>]

On 12.09.14 17:28, Alex Williamson wrote:
> On Fri, 2014-09-12 at 16:27 +0530, 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>

I think you want to CC Paolo, as according to MAINTAINERS he's
maintaining the memory API.


Alex

>> ---
> 
> Looks ok to me.
> 
> Acked-by: Alex Williamson <alex.williamson@redhat.com>
> 
>> 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;
>> @@ -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;
>>      }
>>  
> 
> 
>