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

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

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?

Thanks
Wen Congyang

> Changes from v7 to v8:
> 1. addressed Hatayama's comments
> 
> Changes from v6 to v7:
> 1. addressed Jan's comments
> 2. fix some bugs
> 3. store cpu's state into the vmcore
> 
> Changes from v5 to v6:
> 1. allow user to dump a fraction of the memory
> 2. fix some bugs
> 
> Changes from v4 to v5:
> 1. convert the new command dump to QAPI 
> 
> Changes from v3 to v4:
> 1. support it to run asynchronously
> 2. add API to cancel dumping and query dumping progress
> 3. add API to control dumping speed
> 4. auto cancel dumping when the user resumes vm, and the status is failed.
> 
> Changes from v2 to v3:
> 1. address Jan Kiszka's comment
> 
> Changes from v1 to v2:
> 1. fix virt addr in the vmcore.
> 
> Wen Congyang (16):
>   Add API to create memory mapping list
>   Add API to check whether a physical address is I/O address
>   implement cpu_get_memory_mapping()
>   Add API to check whether paging mode is enabled
>   Add API to get memory mapping
>   Add API to get memory mapping without do paging
>   target-i386: Add API to write elf notes to core file
>   target-i386: Add API to write cpu status to core file
>   target-i386: add API to get dump info
>   make gdb_id() generally avialable
>   introduce a new monitor command 'dump' to dump guest's memory
>   support to cancel the current dumping
>   support to query dumping status
>   run dump at the background
>   support detached dump
>   allow user to dump a fraction of the memory
> 
>  Makefile.target                   |    3 +
>  configure                         |    8 +
>  cpu-all.h                         |   66 +++
>  cpu-common.h                      |    2 +
>  dump.c                            |  980 +++++++++++++++++++++++++++++++++++++
>  dump.h                            |   23 +
>  elf.h                             |    5 +
>  exec.c                            |   11 +
>  gdbstub.c                         |    9 -
>  gdbstub.h                         |    9 +
>  hmp-commands.hx                   |   44 ++
>  hmp.c                             |   89 ++++
>  hmp.h                             |    3 +
>  memory_mapping.c                  |  290 +++++++++++
>  memory_mapping.h                  |   60 +++
>  monitor.c                         |    7 +
>  qapi-schema.json                  |   58 +++
>  qmp-commands.hx                   |  110 +++++
>  target-i386/arch_dump.c           |  433 ++++++++++++++++
>  target-i386/arch_memory_mapping.c |  271 ++++++++++
>  vl.c                              |    5 +-
>  21 files changed, 2475 insertions(+), 11 deletions(-)
>  create mode 100644 dump.c
>  create mode 100644 dump.h
>  create mode 100644 memory_mapping.c
>  create mode 100644 memory_mapping.h
>  create mode 100644 target-i386/arch_dump.c
>  create mode 100644 target-i386/arch_memory_mapping.c
> 
> 
> 
> 
>