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

[Luiz Capitulino <lcapitulino@redhat.com>]

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