Re: [Qemu-devel] [RFC][PATCH 00/16 v6] introducing a new, dedicated memory dump mechanism

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

At 02/09/2012 11:16 AM, 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.

Hi, Jan Kiszka

At 01/10/2012 09:30 PM, Luiz Capitulino Wrote:
> Btw, I'd like to have an ack from Jan for the general approach of this
> command.
> 

Do you agree with the general approach of this command?

Thanks
Wen Congyang

> 
> 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.
> 5. 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.
> 
> 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):
>   monitor: introduce qemu_suspend_monitor()/qemu_resume_monitor()
>   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
>   target-i386: Add API to write elf notes to core file
>   target-i386: Add API to add extra memory mapping
>   target-i386: add API to get dump info
>   introduce a new monitor command 'dump' to dump guest's memory
>   run dump at the background
>   support detached dump
>   support to cancel the current dumping
>   support to set dumping speed
>   support to query dumping status
>   auto cancel dumping after vm state is changed to run
>   allow user to dump a fraction of the memory
> 
>  Makefile.target         |   11 +-
>  cpu-all.h               |   18 +
>  cpu-common.h            |    2 +
>  dump.c                  |  885 +++++++++++++++++++++++++++++++++++++++++++++++
>  dump.h                  |   13 +
>  exec.c                  |   16 +
>  hmp-commands.hx         |   49 +++
>  hmp.c                   |   49 +++
>  hmp.h                   |    4 +
>  memory_mapping.c        |  222 ++++++++++++
>  memory_mapping.h        |   41 +++
>  monitor.c               |   37 ++
>  monitor.h               |    2 +
>  qapi-schema.json        |   72 ++++
>  qmp-commands.hx         |  119 +++++++
>  target-i386/arch-dump.c |  574 ++++++++++++++++++++++++++++++
>  vl.c                    |    5 +-
>  17 files changed, 2112 insertions(+), 7 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
> 
>