Re: [Qemu-devel] [RFC][PATCH 05/16 v8] Add API to get memory mapping

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

At 03/07/2012 11:27 PM, HATAYAMA Daisuke Wrote:
> From: Wen Congyang <wency@cn.fujitsu.com>
> Subject: [RFC][PATCH 05/16 v8] Add API to get memory mapping
> Date: Fri, 02 Mar 2012 18:18:23 +0800
> 
>> Add API to get all virtual address and physical address mapping.
>> If there is no virtual address for some physical address, the virtual
>> address is 0.
>>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> ---
>>  memory_mapping.c |   88 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  memory_mapping.h |    8 +++++
>>  2 files changed, 96 insertions(+), 0 deletions(-)
>>
>> diff --git a/memory_mapping.c b/memory_mapping.c
>> index 718f271..f74c5d0 100644
>> --- a/memory_mapping.c
>> +++ b/memory_mapping.c
>> @@ -164,3 +164,91 @@ void memory_mapping_list_init(MemoryMappingList *list)
>>      list->last_mapping = NULL;
>>      QTAILQ_INIT(&list->head);
>>  }
>> +
>> +int qemu_get_guest_memory_mapping(MemoryMappingList *list)
>> +{
>> +    CPUState *env;
>> +    MemoryMapping *memory_mapping;
>> +    RAMBlock *block;
>> +    ram_addr_t offset, length, m_length;
>> +    target_phys_addr_t m_phys_addr;
>> +    int ret;
>> +    bool paging_mode;
>> +
>> +#if defined(CONFIG_HAVE_GET_MEMORY_MAPPING)
>> +    paging_mode = cpu_paging_enabled(first_cpu);
>> +    if (paging_mode) {
>> +        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 in the memory mapping's list:
>> +     * 1. the guest doesn't use paging
>> +     * 2. the guest is in 2nd kernel, and the memory used by 1st kernel is not
>> +     *    in paging table
>> +     * add them into memory mapping's list
>> +     */
>> +    QLIST_FOREACH(block, &ram_list.blocks, next) {
> 
> How does the memory portion referenced by PT_LOAD program headers with
> p_vaddr == 0 looks through gdb? If we cannot access such portions,
> part not referenced by the page table CR3 has is unnecessary, isn't
> it?

The part is unnecessary if you use gdb. But it is necessary if you use crash.

Thanks
Wen Congyang

> 
> Thanks.
> HATAYAMA, Daisuke
> 
>