Marc-André Lureau <[email protected]> writes:
> Add a new 'info ramblock-attributes' HMP command and the corresponding
> 'x-query-ramblock-attributes' QMP command to display the shared/private
> memory attributes for ram blocks.
>
> The QMP command returns structured data (RamBlockAttributesInfo list
> with per-range shared/populated attributes), while HMP formats it for
> human consumption.
>
> This is useful for debugging confidential guests (TDX, SNP) to inspect
> which memory regions are shared vs private, and their population state
> when a RamDiscardManager is present (e.g. virtio-mem).
>
> Signed-off-by: Marc-André Lureau <[email protected]>
> ---
> qapi/machine.json | 55 +++++++++++++++++++++++++++++++++
> include/monitor/hmp.h | 1 +
> hw/core/machine-hmp-cmds.c | 32 +++++++++++++++++++
> system/ram-block-attributes.c | 72
> +++++++++++++++++++++++++++++++++++++++++++
> hmp-commands-info.hx | 13 ++++++++
> 5 files changed, 173 insertions(+)
>
> diff --git a/qapi/machine.json b/qapi/machine.json
> index 685e4e29b87..aac8a235cf6 100644
> --- a/qapi/machine.json
> +++ b/qapi/machine.json
I have a few fairly ignorant questions. They may or may not indicate a
need for doc improvements.
> @@ -1738,6 +1738,61 @@
> 'returns': 'HumanReadableText',
> 'features': [ 'unstable' ] }
>
> +##
> +# @RamBlockAttributeRange:
> +#
> +# A contiguous range within a ram block with uniform attributes.
RAM please. More of the same below, not flagging it again.
> +#
> +# @start: start offset in bytes within the ram block
> +#
> +# @length: length in bytes of the range
> +#
> +# @shared: true if the range is shared, false if private
What does it mean for a range to be shared?
> +#
> +# @populated: true if the range is populated (only present when a
> +# RamDiscardManager is managing the block)
What's a RamDiscardManager?
> +#
> +# Since: 11.1
> +##
> +{ 'struct': 'RamBlockAttributeRange',
> + 'data': { 'start': 'uint64',
> + 'length': 'uint64',
> + 'shared': 'bool',
> + '*populated': 'bool' } }
> +
> +##
> +# @RamBlockAttributesInfo:
> +#
> +# Shared/private memory attributes for a ram block.
> +#
> +# @name: the ram block identifier
Where do RAM block names come from?
> +#
> +# @ranges: list of attribute ranges
> +#
> +# Since: 11.1
> +##
> +{ 'struct': 'RamBlockAttributesInfo',
> + 'data': { 'name': 'str',
> + 'ranges': [ 'RamBlockAttributeRange' ] } }
> +
> +##
> +# @x-query-ramblock-attributes:
> +#
> +# Query ram block shared/private attributes. This is useful
> +# to debug confidential guests.
What are RAM blocks?
> +#
> +# Features:
> +#
> +# @unstable: This command is meant for debugging.
> +#
> +# Returns: list of ram block attributes
> +#
> +# Since: 11.1
> +##
> +{ 'command': 'x-query-ramblock-attributes',
> + 'returns': [ 'RamBlockAttributesInfo' ],
> + 'features': [ 'unstable' ] }
> +
> ##
> # @x-query-roms:
> #
[...]
