Re: [Qemu-devel] [RFC][PATCH 04/14 v7] Add API to get memory mapping

[Wen Congyang]

At 03/01/2012 03:11 PM, HATAYAMA Daisuke Wrote:
> From: Wen Congyang <address@hidden>
> Subject: Re: [RFC][PATCH 04/14 v7] Add API to get memory mapping
> Date: Thu, 01 Mar 2012 14:17:53 +0800
> 
>> At 03/01/2012 02:01 PM, HATAYAMA Daisuke Wrote:
>>> From: Wen Congyang <address@hidden>
>>> Subject: [RFC][PATCH 04/14 v7] Add API to get memory mapping
>>> Date: Thu, 01 Mar 2012 10:43:13 +0800
>>>
>>>> +int qemu_get_guest_memory_mapping(MemoryMappingList *list)
>>>> +{
>>>> +    CPUState *env;
>>>> +    MemoryMapping *memory_mapping;
>>>> +    RAMBlock *block;
>>>> +    ram_addr_t offset, length;
>>>> +    int ret;
>>>> +
>>>> +#if defined(CONFIG_HAVE_GET_MEMORY_MAPPING)
>>>> +    for (env = first_cpu; env != NULL; env = env->next_cpu) {
>>>> +        ret = cpu_get_memory_mapping(list, env);
>>>> +        if (ret < 0) {
>>>> +            return -1;
>>>> +        }
>>>> +    }
>>>> +#else
>>>> +    return -2;
>>>> +#endif
>>>> +
>>>> +    /* some memory may be not mapped, add them into memory mapping's list 
>>>> */
>>>
>>> The part from here is logic fully for 2nd kernel? If so, I think it
>>> better to describe why this addtional mapping is needed; we should
>>> assume most people doesn't know kdump mechanism.
>>
>> Not only for 2nd kernel. If the guest has 1 vcpu, and is in the 2nd kernel,
>> we need this logic for 1st kernel.
>>
> 
> So you should describe two cases explicitly. I don't understand them
> from ``some memory''.
> 
> and please consider cleanup below too. Conditionals over two lines are
> hard to read.

OK. I will fix it.

Thanks
Wen Congyang

> 
>>>
>>> I think it more readable if shortening memory_mapping->phys_addr and
>>> memmory_maping->length at the berinning of the innermost foreach loop.
>>>
>>>   m_phys_addr = memory_mapping->phys_addr;
>>>   m_length = memory_mapping->length;
>>>
>>> Then, each conditionals becomes compact.
> 
> Thanks.
> HATAYAMA, Daisuke
> 
>