Re: [Qemu-devel] [PATCH v3 5/5] qmp: add pmemload command

[Eric Blake]

On 05/21/2018 10:36 AM, Simon Ruderich wrote:
> Adapted patch from Baojun Wang [1] with the following commit message:
>
>      I found this could be useful to have qemu-softmmu as a cross
>      debugger (launch with -s -S command line option), then if we can
>      have a command to load guest physical memory, we can use cross gdb
>      to do some target debug which gdb cannot do directly.
>
> pmemload is necessary to directly write physical memory which is not
> possible with gdb alone as it uses only logical addresses.
>
> The QAPI for pmemload uses "val" as parameter name for the physical
> address. This name is not very descriptive but is consistent with the
> existing pmemsave. Changing the parameter name of pmemsave is not
> possible without breaking the existing API.
>
> [1]: https://lists.gnu.org/archive/html/qemu-trivial/2014-04/msg00074.html
>
> Based-on-patch-by: Baojun Wang <address@hidden>
> Signed-off-by: Simon Ruderich <address@hidden>
> ---
>   cpus.c          | 41 +++++++++++++++++++++++++++++++++++++++++
>   hmp-commands.hx | 14 ++++++++++++++
>   hmp.c           | 12 ++++++++++++
>   hmp.h           |  1 +
>   qapi/misc.json  | 20 ++++++++++++++++++++
>   5 files changed, 88 insertions(+)

I haven't closely reviewed this, but a quick note:


> +++ b/qapi/misc.json
> @@ -1219,6 +1219,26 @@
>   { 'command': 'pmemsave',
>     'data': {'val': 'int', 'size': 'int', 'filename': 'str'} }
>   
> +##
> +# @pmemload:
> +#
> +# Load a portion of guest physical memory from a file.
> +#
> +# @val: the physical address of the guest to start from
> +#
> +# @size: the size of memory region to load
> +#
> +# @offset: the offset in the file to start from
> +#
> +# @filename: the file to load the memory from as binary data
> +#
> +# Returns: Nothing on success
> +#
> +# Since: 2.13

There was no 2.13 release, and this feature has missed the 3.0 
deadlines, so it would need to say 'Since: 3.1'

> +##
> +{ 'command': 'pmemload',
> +  'data': {'val': 'int', 'size': 'int', 'offset': 'int', 'filename': 'str'} }
> +
>   ##
>   # @cont:
>   #

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org