Re: [Qemu-devel] [PATCH 00/43] Windbg supporting

[Mihail Abakumov]

Alistair Francis писал 2017-09-26 20:26:
> On Tue, Sep 26, 2017 at 4:04 AM, Mihail Abakumov
> <address@hidden> wrote:
> > We made the debugger module WinDbg (like GDB) for QEMU. This is the 
> > replacement of the remote stub in Windows kernel. Used for remote 
> > Windows kernel debugging without debugging mode.
> >
> > WinDbg is a multipurpose debugger for the Microsoft Windows computer 
> > operating system, distributed by Microsoft. Recent versions of WinDbg 
> > have been and are being distributed as part of the free Debugging 
> > Tools for Windows suite.
> >
> > How to start debugging QEMU using WinDbg:
> >   Run QEMU with next option:
> >     -windbg pipe:<name>
> >   QEMU will start and pause for waiting WinDbg connection.
> >   Run WinDbg with next options:
> >     -b -k com:pipe,baud=115200,port=\\.\pipe\<name>,resets=0
> >   Wait for debugger connect to kernel.
> >
> > Note: You can add Symbol Search Path in WinDbg such as 
> > srv*c:\tmp*http://msdl.microsoft.com/download/symbols.
> >
> > How it works:
> > The WinDbg debugger has the possibility of connecting to a remote 
> > debug service (Kdsrv.exe) in the Windows kernel. Therefore, it is 
> > possible to connect to the guest system running in the QEMU emulator. 
> > Kernel debugging is possible only with the enabled debugging mode, may 
> > change at the same time. Our module of WinDbg debugger for QEMU is an 
> > alternative of the remote debugging service in the kernel. Thus, the 
> > debugger connects to the debugging module, not to the kernel of the 
> > operating system. The module obtains all the necessary information 
> > answering debugger requests from the QEMU emulator. At the same time 
> > for debugging there is no need to enable debugging mode in the kernel. 
> > This leads to hidden debugging. Our module supports all features of 
> > WinDbg regarding remote debugging, besides interception of events and 
> > exceptions. Only i386 is supported now.
> >
> > ---
>
> This looks pretty cool! Thanks for sending the patches.
>
> I had a quick look through it. I think something worth keeping in mind
> is that ideally we want this to support every target. So generally
> it's best to have the target specific code in the target/ directory
> and then make the stubs all generic. At the moment it looks like there
> is a fair bit of x86 specific code in the debugger.
>
> I guess this is a weird case though as Windows only runs on x86, but
> in the future it sounds like ARM will be supported and it'd be great
> if this could be easily extended to support that.
>
> Thanks,
> Alistair

Once again, thank you for your feedback.

I done it. I moved the target specific code in the 'target/' directory 
and made the stub for unsupported 'targets'.
Problems with targets received by Patchew I've already fixed.

Thanks,
Mihail Abakumov

> > Mihail Abakumov (43):
> >       windbg: added empty windbgstub files
> >       windbg: added windbg's KD header file
> >       windbg: modified windbgkd.h
> >       windbg: added '-windbg' option
> >       windbg: added helper features
> >       windbg: added WindbgState
> >       windbg: added chardev
> >       windbg: hook to wrmsr operation
> >       windbg: handler of fs/gs register
> >       windbg: structures for parsing data stream
> >       windbg: parsing data stream
> >       windbg: send data and control packets
> >       windbg: handler of parsing context
> >       windbg: init DBGKD_ANY_WAIT_STATE_CHANGE
> >       windbg: sized data buffer
> >       windbg: generate ExceptionStateChange
> >       windbg: generate LoadSymbolsStateChange
> >       windbg: windbg_vm_stop
> >       windbg: implemented windbg_process_control_packet
> >       windbg: implemented windbg_process_data_packet
> >       windbg: implemented windbg_process_manipulate_packet
> >       windbg: implemented kd_api_read_virtual_memory and 
> > kd_api_read_virtual_memory
> >       windbg: kernel's structures
> >       windbg: implemented kd_api_get_context and kd_api_set_context
> >       windbg: implemented kd_api_read_control_space and 
> > kd_api_write_control_space
> >       windbg: implemented windbg_read_context
> >       windbg: implemented windbg_write_context
> >       windbg: implemented windbg_read_ks_regs
> >       windbg: implemented windbg_write_ks_regs
> >       windbg: implemented windbg_set_sr
> >       windbg: implemented windbg_set_dr
> >       windbg: implemented windbg_set_dr7
> >       windbg: implemented windbg_hw_breakpoint_insert and 
> > windbg_hw_breakpoint_remove
> >       windbg: implemented kd_api_write_breakpoint and 
> > kd_api_restore_breakpoint
> >       windbg: debug exception subscribing
> >       windbg: implemented kd_api_continue
> >       windbg: implemented kd_api_read_io_space and 
> > kd_api_write_io_space
> >       windbg: implemented kd_api_read_physical_memory and 
> > kd_api_write_physical_memory
> >       windbg: implemented kd_api_get_version
> >       windbg: implemented kd_api_read_msr and kd_api_write_msr
> >       windbg: implemented kd_api_search_memory
> >       windbg: implemented kd_api_fill_memory
> >       windbg: implemented kd_api_query_memory
> >
> >
> >  Makefile.target                 |    5
> >  cpus.c                          |   18
> >  gdbstub.c                       |    4
> >  include/exec/windbgkd.h         | 1030 ++++++++++++++++++++++
> >  include/exec/windbgstub-utils.h |  132 +++
> >  include/exec/windbgstub.h       |   21
> >  include/sysemu/sysemu.h         |    2
> >  qemu-options.hx                 |    8
> >  target/i386/misc_helper.c       |    3
> >  vl.c                            |    8
> >  windbgstub-utils.c              | 1788 
> > +++++++++++++++++++++++++++++++++++++++
> >  windbgstub.c                    |  464 ++++++++++
> >  12 files changed, 3482 insertions(+), 1 deletion(-)
> >  create mode 100755 include/exec/windbgkd.h
> >  create mode 100755 include/exec/windbgstub-utils.h
> >  create mode 100755 include/exec/windbgstub.h
> >  create mode 100755 windbgstub-utils.c
> >  create mode 100755 windbgstub.c
> >
> > --
> > Thanks,
> > Mihail Abakumov