Re: [Qemu-devel] [PATCH] dump: add Windows dump format to dump-guest-memory

[Viktor Prutyanov <viktor.prutyanov@virtuozzo.com>]

On Tue, 17 Apr 2018 14:03:18 +0200
Marc-André Lureau <marcandre.lureau@gmail.com> wrote:

> Hi
> 
> On Mon, Apr 16, 2018 at 9:40 PM, Viktor Prutyanov
> <viktor.prutyanov@virtuozzo.com> wrote:
> > This patch adds Windows crashdumping feature. Now QEMU can produce
> > crashdump file understandable for WinDbg. The crashdump will be
> > obtained by joining physical memory dump and 8K header exposed
> > through vmcoreinfo/fw_cfg device by guest driver at BSOD time.
> > Option '-w' was added to dump-guest-memory command. At the moment,
> > only x64 configuration is supported. Suitable driver can be found at
> > https://github.com/virtio-win/kvm-guest-drivers-windows/tree/master/fwcfg64
> >
> > Signed-off-by: Viktor Prutyanov <viktor.prutyanov@virtuozzo.com>  
> 
> Why do you reuse VMCOREINFO_FORMAT_ELF ? It looks like a hack to me. I
> can imagine there is some code similarity for new format support, like
> the cpu_physical_memory_read(addr, s->guest_note, size), but what else
> do you gain from reusing VMCOREINFO_FORMAT_ELF instead of introducing
> explicitely a new windows dump specific format ? This could really
> help avoiding some confusion imho

Reuse of VMCOREINFO_FORMAT_ELF makes possible to produce valid ELF-dump
which can be converted to Windows dump format later with another tool.