Re: [PATCH V8 12/39] memory: flat section iterator

[Steven Sistare]

On 7/3/2022 3:52 AM, Peng Liang wrote:
> On 6/15/2022 10:51 PM, Steve Sistare wrote:
>> Add an iterator over the sections of a flattened address space.
>>
>> Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
>> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>> ---
>>  include/exec/memory.h | 31 +++++++++++++++++++++++++++++++
>>  softmmu/memory.c      | 20 ++++++++++++++++++++
>>  2 files changed, 51 insertions(+)
>>
>> diff --git a/include/exec/memory.h b/include/exec/memory.h
>> index a03301d..6a257a4 100644
>> --- a/include/exec/memory.h
>> +++ b/include/exec/memory.h
>> @@ -2343,6 +2343,37 @@ void 
>> memory_region_set_ram_discard_manager(MemoryRegion *mr,
>>                                             RamDiscardManager *rdm);
>>  
>>  /**
>> + * memory_region_section_cb: callback for 
>> address_space_flat_for_each_section()
>> + *
>> + * @mrs: MemoryRegionSection of the range
>> + * @opaque: data pointer passed to address_space_flat_for_each_section()
>> + * @errp: error message, returned to the address_space_flat_for_each_section
>> + *        caller.
>> + *
>> + * Returns: non-zero to stop the iteration, and 0 to continue.  The same
>> + * non-zero value is returned to the address_space_flat_for_each_section 
>> caller.
>> + */
>> +
>> +typedef int (*memory_region_section_cb)(MemoryRegionSection *mrs,
>> +                                        void *opaque,
>> +                                        Error **errp);
>> +
>> +/**
>> + * address_space_flat_for_each_section: walk the ranges in the address space
>> + * flat view and call @func for each.  Return 0 on success, else return 
>> non-zero
>> + * with a message in @errp.
>> + *
>> + * @as: target address space
>> + * @func: callback function
>> + * @opaque: passed to @func
>> + * @errp: passed to @func
>> + */
>> +int address_space_flat_for_each_section(AddressSpace *as,
>> +                                        memory_region_section_cb func,
>> +                                        void *opaque,
>> +                                        Error **errp);
>> +
>> +/**
>>   * memory_region_find: translate an address/size relative to a
>>   * MemoryRegion into a #MemoryRegionSection.
>>   *
>> diff --git a/softmmu/memory.c b/softmmu/memory.c
>> index 0fe6fac..e5aefdd 100644
>> --- a/softmmu/memory.c
>> +++ b/softmmu/memory.c
>> @@ -2683,6 +2683,26 @@ bool memory_region_is_mapped(MemoryRegion *mr)
>>      return !!mr->container || mr->mapped_via_alias;
>>  }
>>  
>> +int address_space_flat_for_each_section(AddressSpace *as,
>> +                                        memory_region_section_cb func,
>> +                                        void *opaque,
>> +                                        Error **errp)
>> +{
>> +    FlatView *view = address_space_get_flatview(as);
>> +    FlatRange *fr;
>> +    int ret;
>> +
>> +    FOR_EACH_FLAT_RANGE(fr, view) {
>> +        MemoryRegionSection mrs = section_from_flat_range(fr, view);
>> +        ret = func(&mrs, opaque, errp);
>> +        if (ret) {
>> +            return ret;
>> +        }
>> +    }
>> +
> 
> Hi Steve,
> I guess a flatview_unref(view) is missing here? Because the return value
> of address_space_get_flatview has been flatview_ref.

Yes!  Good catch, will fix, thanks - Steve

>> +    return 0;
>> +}
>> +
>>  /* Same as memory_region_find, but it does not add a reference to the
>>   * returned region.  It must be called from an RCU critical section.
>>   */