Re: [Qemu-devel] [RFC][PATCH 00/16 v8] introducing a new, dedicated memory dump mechanism

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

At 03/08/2012 01:38 AM, Luiz Capitulino Wrote:
> On Mon, 5 Mar 2012 21:41:02 -0300
> Luiz Capitulino <lcapitulino@redhat.com> wrote:
> 
>> On Mon, 05 Mar 2012 17:12:00 +0800
>> Wen Congyang <wency@cn.fujitsu.com> wrote:
>>
>>> At 03/02/2012 05:59 PM, Wen Congyang Wrote:
>>>> Hi, all
>>>>
>>>> 'virsh dump' can not work when host pci device is used by guest. We have
>>>> discussed this issue here:
>>>> http://lists.nongnu.org/archive/html/qemu-devel/2011-10/msg00736.html
>>>>
>>>> The last version is here:
>>>> http://lists.nongnu.org/archive/html/qemu-devel/2012-02/msg04228.html
>>>>
>>>> We have determined to introduce a new command dump to dump memory. The core
>>>> file's format can be elf.
>>>>
>>>> Note:
>>>> 1. The guest should be x86 or x86_64. The other arch is not supported now.
>>>> 2. If you use old gdb, gdb may crash. I use gdb-7.3.1, and it does not crash.
>>>> 3. If the OS is in the second kernel, gdb may not work well, and crash can
>>>>    work by specifying '--machdep phys_addr=xxx' in the command line. The
>>>>    reason is that the second kernel will update the page table, and we can
>>>>    not get the page table for the first kernel.
>>>> 4. The cpu's state is stored in QEMU note. You neet to modify crash to use
>>>>    it to calculate phys_base.
>>>> 5. If the guest OS is 32 bit and the memory size is larger than 4G, the vmcore
>>>>    is elf64 format. You should use the gdb which is built with --enable-64-bit-bfd.
>>>> 6. This patchset is based on the upstream tree, and apply one patch that is still
>>>>    in Luiz Capitulino's tree, because I use the API qemu_get_fd() in this patchset.
>>>>
>>>
>>> Hi, Jan, Luiz Capitulino
>>> Do you have any comments?
>>
>> I haven't had a chance to review it yet, will do in the next few days.
> 
> Wen, I've started reviewing this but before I ask you to make more changes
> to this series, it's better to wait for a conclusion of the asynchronous
> command discussion thread:
> 
>  http://lists.gnu.org/archive/html/qemu-devel/2012-03/msg01067.html

OK. I see this thread.

Thanks
Wen Congyang

> 
> 
>