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

[HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>]

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.

Thanks.
HATAYAMA, Daisuke