[Qemu-devel] [RFC][PATCT 0/14 v4] dump memory when host pci device is used by guest

[Wen Congyang]

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.

Change 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.

Change from v2 to v3:
1. address Jan Kiszka's comment

Changes from v1 to v2:
1. fix virt addr in the vmcore.

Wen Congyang (14):
  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

 Makefile.target         |   11 +-
 cpu-all.h               |   18 +
 cpu-common.h            |    2 +
 dump.c                  |  796 +++++++++++++++++++++++++++++++++++++++++++++++
 dump.h                  |   14 +
 exec.c                  |   20 ++
 hmp-commands.hx         |   47 +++
 hmp.c                   |   24 ++
 hmp.h                   |    3 +
 memory_mapping.c        |  185 +++++++++++
 memory_mapping.h        |   39 +++
 monitor.c               |   10 +
 qapi-schema.json        |   54 ++++
 qmp-commands.hx         |  117 +++++++
 target-i386/arch-dump.c |  574 ++++++++++++++++++++++++++++++++++
 15 files changed, 1909 insertions(+), 5 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