Re: [Qemu-devel] [RFC][PATCT 0/5 v2] dump memory when host pci device is used by guest

[Jan Kiszka]

On 2011-12-09 08:57, 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
> 
> 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.
> 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. 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.
> 
> Changes from v1 to v2:
> 1. fix virt addr in the vmcore.
> 
> Wen Congyang (5):
>   Add API to create memory mapping list
>   Add API to check whether a physical address is I/O address
>   target-i386: implement cpu_get_memory_mapping()
>   Add API to get memory mapping
>   introduce a new monitor command 'dump' to dump guest's memory
> 
>  Makefile.target      |    9 +-
>  cpu-all.h            |   10 +
>  cpu-common.h         |    1 +
>  dump.c               |  722 
> ++++++++++++++++++++++++++++++++++++++++++++++++++
>  dump.h               |    6 +
>  exec.c               |   20 ++
>  hmp-commands.hx      |   16 ++
>  memory_mapping.c     |  183 +++++++++++++
>  memory_mapping.h     |   30 ++
>  monitor.c            |    3 +
>  qmp-commands.hx      |   24 ++
>  target-i386/helper.c |  239 +++++++++++++++++
>  12 files changed, 1259 insertions(+), 4 deletions(-)
>  create mode 100644 dump.c
>  create mode 100644 dump.h
>  create mode 100644 memory_mapping.c
>  create mode 100644 memory_mapping.h

A general remark regarding code organization: Please factor out the
target specific bits and push them into target-*/dump.[ch] or whatever
appropriate file in that folder. Ugly #ifdefs should be avoided in
generic code as far as possible.

Thanks,
Jan

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