Re: [PATCH v3 31/49] i386/sev: Update query-sev QAPI format to handle SEV-SNP

[Markus Armbruster <armbru@redhat.com>]

Michael Roth <michael.roth@amd.com> writes:

> Most of the current 'query-sev' command is relevant to both legacy
> SEV/SEV-ES guests and SEV-SNP guests, with 2 exceptions:
>
>   - 'policy' is a 64-bit field for SEV-SNP, not 32-bit, and
>     the meaning of the bit positions has changed
>   - 'handle' is not relevant to SEV-SNP
>
> To address this, this patch adds a new 'sev-type' field that can be
> used as a discriminator to select between SEV and SEV-SNP-specific
> fields/formats without breaking compatibility for existing management
> tools (so long as management tools that add support for launching
> SEV-SNP guest update their handling of query-sev appropriately).
>
> The corresponding HMP command has also been fixed up similarly.
>
> Signed-off-by: Michael Roth <michael.roth@amd.com>
> ---
>  qapi/misc-target.json | 71 ++++++++++++++++++++++++++++++++++---------
>  target/i386/sev.c     | 50 ++++++++++++++++++++----------
>  target/i386/sev.h     |  3 ++
>  3 files changed, 94 insertions(+), 30 deletions(-)
>
> diff --git a/qapi/misc-target.json b/qapi/misc-target.json
> index 4e0a6492a9..daceb85d95 100644
> --- a/qapi/misc-target.json
> +++ b/qapi/misc-target.json
> @@ -47,6 +47,49 @@
>             'send-update', 'receive-update' ],
>    'if': 'TARGET_I386' }
>  
> +##
> +# @SevGuestType:
> +#
> +# An enumeration indicating the type of SEV guest being run.
> +#
> +# @sev:     The guest is a legacy SEV or SEV-ES guest.

Single space after ':', please.

Recommend a blank line between argument descriptions.

> +# @sev-snp: The guest is an SEV-SNP guest.
> +#
> +# Since: 6.2

The type is since 9.1, but its members become results of query-sev,
where they are since 2.12.  See also my reply to Daniel's question on
PATCH 21.

> +##
> +{ 'enum': 'SevGuestType',
> +  'data': [ 'sev', 'sev-snp' ],
> +  'if': 'TARGET_I386' }
> +
> +##
> +# @SevGuestInfo:
> +#
> +# Information specific to legacy SEV/SEV-ES guests.
> +#
> +# @policy: SEV policy value

I know you're just moving existing documentation.  Still: this is rather
sparse.  Where would I find what numbers to pass for @policy?

> +#
> +# @handle: SEV firmware handle
> +#
> +# Since: 2.12
> +##
> +{ 'struct': 'SevGuestInfo',
> +  'data': { 'policy': 'uint32',
> +            'handle': 'uint32' },
> +  'if': 'TARGET_I386' }
> +
> +##
> +# @SevSnpGuestInfo:
> +#
> +# Information specific to SEV-SNP guests.
> +#
> +# @snp-policy: SEV-SNP policy value

Same question.

> +#
> +# Since: 6.2

9.1

> +##
> +{ 'struct': 'SevSnpGuestInfo',
> +  'data': { 'snp-policy': 'uint64' },
> +  'if': 'TARGET_I386' }
> +
>  ##
>  # @SevInfo:
>  #
> @@ -60,25 +103,25 @@
>  #
>  # @build-id: SEV FW build id
>  #
> -# @policy: SEV policy value
> -#
>  # @state: SEV guest state
>  #
> -# @handle: SEV firmware handle
> +# @sev-type: Type of SEV guest being run
>  #
>  # Since: 2.12
>  ##
> -{ 'struct': 'SevInfo',
> -    'data': { 'enabled': 'bool',
> -              'api-major': 'uint8',
> -              'api-minor' : 'uint8',
> -              'build-id' : 'uint8',
> -              'policy' : 'uint32',
> -              'state' : 'SevState',
> -              'handle' : 'uint32'
> -            },
> -  'if': 'TARGET_I386'
> -}
> +{ 'union': 'SevInfo',
> +  'base': { 'enabled': 'bool',
> +            'api-major': 'uint8',
> +            'api-minor' : 'uint8',
> +            'build-id' : 'uint8',
> +            'state' : 'SevState',
> +            'sev-type' : 'SevGuestType' },
> +  'discriminator': 'sev-type',
> +  'data': {
> +      'sev': 'SevGuestInfo',
> +      'sev-snp': 'SevSnpGuestInfo' },
> +  'if': 'TARGET_I386' }
> +
>  
>  ##
>  # @query-sev:

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