Re: [Qemu-devel] [PATCH 0/8] Basic device state visualization

[Blue Swirl <blauwirbel@gmail.com>]

On 5/14/10, Jan Kiszka <jan.kiszka@siemens.com> wrote:
> While recently fixing the SCSI reset issues, I once again had the need
>  for displaying the state of involved devices. So far the common approach
>  is to attach gdb to qemu (or even inject some printf). But that time I
>  hacked up a 30-minute patch to dump the vmstate of any (fully converted)
>  qdev device.
>
>  This series now lays the ground for more sophisticated visulization. It
>  adds the monitor command 'device_show <qdev-path>', freezes the vmstate
>  of the addressed device, sticks it into a QMP dict, and either transmit
>  this via QMP or pretty-prints it on a monitor console. Some example:
>
>  (qemu) device_show /i440FX-pcihost/pci.0/piix3-usb-uhci
>  dev: piix3-usb-uhci, id ""
>   dev.
>     version_id:         00000002
>     config:             a0 7d d1 00 00 00 00 00 - b0 7e d1 00 00 00 00 00
>                         ...
>     irq_state:          00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
>   num_ports_vmstate:    02
>   ports[00].
>       ctrl:             0083
>   ports[01].
>       ctrl:             0080
>   cmd:                  00c1
>   status:               0000
>   intr:                 0000
>   frnum:                0077
>   fl_base_addr:         0fffc000
>   sof_timing:           40
>   status2:              00
>   frame_timer:          0000000000cb2bd0
>
>  Basically, this is the level of support I recently saw in a
>  demonstration of some commercial simulator as well. We are just lacking
>  support for the yet unconverted devices. And I think we can even do
>  better on the long term, e.g. by annotating state variables that contain
>  flags, or by pretty-printing buffers like the PCI config space, or...
>
>  Let's give this a start, I bet it will be helpful while adding complex
>  device models like AHCI or EHCI. Looking forward to feedback!

Nice! I think this confirms that there is no future for the qdev side
of my yesterday's patch, this is much better.