On 2012-02-15 06:19, Wen Congyang wrote:
> At 02/15/2012 01:35 AM, Jan Kiszka Wrote:
>> On 2012-02-09 04:24, Wen Congyang wrote:
>>> Crash needs extra memory mapping to determine phys_base.
>>>
>>> Signed-off-by: Wen Congyang <we...@cn.fujitsu.com>
>>> ---
>>> cpu-all.h | 2 ++
>>> target-i386/arch-dump.c | 43 +++++++++++++++++++++++++++++++++++++++++++
>>> 2 files changed, 45 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/cpu-all.h b/cpu-all.h
>>> index efb5ba3..290c43a 100644
>>> --- a/cpu-all.h
>>> +++ b/cpu-all.h
>>> @@ -530,10 +530,12 @@ int cpu_write_elf64_note(int fd, CPUState *env, int
>>> cpuid,
>>> target_phys_addr_t *offset);
>>> int cpu_write_elf32_note(int fd, CPUState *env, int cpuid,
>>> target_phys_addr_t *offset);
>>> +int cpu_add_extra_memory_mapping(MemoryMappingList *list);
>>> #else
>>> #define cpu_get_memory_mapping(list, env)
>>> #define cpu_write_elf64_note(fd, env, cpuid, offset) ({ -1; })
>>> #define cpu_write_elf32_note(fd, env, cpuid, offset) ({ -1; })
>>> +#define cpu_add_extra_memory_mapping(list) ({ 0; })
>>> #endif
>>>
>>> #endif /* CPU_ALL_H */
>>> diff --git a/target-i386/arch-dump.c b/target-i386/arch-dump.c
>>> index 4c0ff77..d96f6ae 100644
>>> --- a/target-i386/arch-dump.c
>>> +++ b/target-i386/arch-dump.c
>>> @@ -495,3 +495,46 @@ int cpu_write_elf32_note(int fd, CPUState *env, int
>>> cpuid,
>>> {
>>> return x86_write_elf32_note(fd, env, cpuid, offset);
>>> }
>>> +
>>> +/* This function is copied from crash */
>>
>> And what does it do there and here? I suppose it is Linux-specific - any
>> version? This should be documented and encoded in the function name.
>>
>>> +static target_ulong get_phys_base_addr(CPUState *env, target_ulong
>>> *base_vaddr)
>>> +{
>>> + int i;
>>> + target_ulong kernel_base = -1;
>>> + target_ulong last, mask;
>>> +
>>> + for (i = 30, last = -1; (kernel_base == -1) && (i >= 20); i--) {
>>> + mask = ~((1LL << i) - 1);
>>> + *base_vaddr = env->idt.base & mask;
>>> + if (*base_vaddr == last) {
>>> + continue;
>>> + }
>>> +
>>> + kernel_base = cpu_get_phys_page_debug(env, *base_vaddr);
>>> + last = *base_vaddr;
>>> + }
>>> +
>>> + return kernel_base;
>>> +}
>>> +
>>> +int cpu_add_extra_memory_mapping(MemoryMappingList *list)
>>
>> Again, what does "extra" mean? Probably guest-specific, no?
>
> crash will calculate the phys_base according to the virtual address and
> physical
> address stored in the PT_LOAD.
Crash is a Linux-only tool, dump must not be restricted to that guest -
but could contain transparent extensions of the file format if needed.
>
> If the vmcore is generated by 'virsh dump'(use migration to implement
> dumping),
> crash calculates the phys_base according to idt.base. The function
> get_phys_base_addr()
> uses the same way to calculates the phys_base.
Hmm, where are those special registers (idt, gdt, tr etc.) stored in the
vmcore file, BTW?
>
> I think crash may work without this. I will verify it.
Does gdb require this?
Jan
--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
