At 02/15/2012 05:21 PM, Jan Kiszka Wrote: > 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?
'virsh dump' uses mirgation to implement dumping now. So the vmcore has all registers. > >> >> I think crash may work without this. I will verify it. I want to modify crash to make it work without this. I am discussing it with Dave Anderson in crash community now. > > Does gdb require this? IIRC, the answer is no. Thanks Wen Congyang > > Jan >