Re: [Qemu-devel] [PATCH 11/11 v10] introduce a new monitor command 'dump-guest-memory' to dump guest's memory

[Wen Congyang <wency@cn.fujitsu.com>]

At 03/23/2012 05:40 PM, HATAYAMA Daisuke Wrote:
> From: Wen Congyang <wency@cn.fujitsu.com>
> Subject: [PATCH 11/11 v10] introduce a new monitor command 'dump-guest-memory' to dump guest's memory
> Date: Tue, 20 Mar 2012 11:57:43 +0800
> 
>> +/* get the memory's offset in the vmcore */
>> +static target_phys_addr_t get_offset(target_phys_addr_t phys_addr,
>> +                                     DumpState *s)
>> +{
>> +    RAMBlock *block;
>> +    target_phys_addr_t offset = s->memory_offset;
>> +    int64_t size_in_block, start;
>> +
>> +    if (s->has_filter) {
>> +        if (phys_addr < s->begin || phys_addr >= s->begin + s->length) {
>> +            return -1;
>> +        }
>> +    }
>> +
>> +    QLIST_FOREACH(block, &ram_list.blocks, next) {
>> +        if (s->has_filter) {
>> +            if (block->offset >= s->begin + s->length ||
>> +                block->offset + block->length <= s->begin) {
>> +                /* This block is out of the range */
>> +                continue;
>> +            }
>> +
>> +            if (s->begin <= block->offset) {
>> +                start = block->offset;
>> +            } else {
>> +                start = s->begin;
>> +            }
>> +
>> +            size_in_block = block->length - (start - block->offset);
>> +            if (s->begin + s->length < block->offset + block->length) {
>> +                size_in_block -= block->offset + block->length -
>> +                                 (s->begin + s->length);
>> +            }
>> +        } else {
>> +            start = block->offset;
>> +            size_in_block = block->length;
>> +        }
>> +
>> +        if (phys_addr >= start && phys_addr < start + size_in_block) {
>> +            return phys_addr - start + offset;
>> +        }
>> +
>> +        offset += size_in_block;
>> +    }
>> +
>> +    return -1;
>> +}
> 
> OK. -1 is assigned to offset when the corresponding memory is filtered
> and so not contained in dumpfile. But please give -1 a name. I want
> the name to tell me the data is filterred.
> 
> Also, I couldn't imagine get_offset() does filtering processing. This
> is important for the purspective of dump because there's data not
> saved in dumpfile. Could you claify this in some way? By moving
> filtering processing to the outside, or splitting it into anotehr
> funciton.

offset should not be -1. I remove the PT_LOAD in the function memory_mapping_filter().
In the previous patchset, Luiz said he wants to squash the filtering
feature to this patch.

Thanks
Wen Congyang

> 
> Thanks.
> HATAYAMA, Daisuke
> 
>