i386/sev: Update query-sev QAPI format to handle SEV-SNP

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>
Co-developed-by:Pankaj Gupta <pankaj.gupta@amd.com>
Signed-off-by: Pankaj Gupta <pankaj.gupta@amd.com>
Message-ID: <20240530111643.1091816-15-pankaj.gupta@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 58 insertions, 14 deletions

diff --git a/qapi/misc-target.json b/qapi/misc-target.json
index 4e0a6492a9..2d7d4d89bd 100644
--- a/qapi/misc-target.json
+++ b/qapi/misc-target.json
@@ -48,6 +48,50 @@
   '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.
+#
+# @sev-snp: The guest is an SEV-SNP guest.
+#
+# Since: 6.2
+##
+{ 'enum': 'SevGuestType',
+  'data': [ 'sev', 'sev-snp' ],
+  'if': 'TARGET_I386' }
+
+##
+# @SevGuestInfo:
+#
+# Information specific to legacy SEV/SEV-ES guests.
+#
+# @policy: SEV policy value
+#
+# @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
+#
+# Since: 9.1
+##
+{ 'struct': 'SevSnpGuestInfo',
+  'data': { 'snp-policy': 'uint64' },
+  'if': 'TARGET_I386' }
+
+##
 # @SevInfo:
 #
 # Information about Secure Encrypted Virtualization (SEV) support
@@ -60,25 +104,25 @@
 #
 # @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: