Re: [Qemu-devel] [PATCH v2 5/5] qmp: add pmemload command

[Eric Blake]

On 04/12/2018 07:50 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>
> ---

Focusing on just the interface:

> +++ b/qapi/misc.json
> @@ -1185,6 +1185,26 @@
>  { '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

Should size be an optional parameter (default read to the end of the file)?

> +#
> +# @offset: the offset in the file to start from

Should offset be an optional parameter (default start reading from
offset 0 of the file)?

> +#
> +# @filename: the file to load the memory from as binary data
> +#
> +# Returns: Nothing on success
> +#
> +# Since: 2.13
> +##
> +{ '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

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