[PATCH v3] qapi: Cleanup SGX related comments and restore @section-size

[Yang Zhong <yang.zhong@intel.com>]

The SGX NUMA patches were merged into Qemu 7.0 release, we need
clarify detailed version history information and also change
some related comments, which make SGX related comments clearer.

The QMP command schema promises backwards compatibility as standard.
We temporarily restore "@section-size", which can avoid incompatible
API breakage. The "@section-size" will be deprecated in 7.2 version.

Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
---
 docs/about/deprecated.rst | 13 +++++++++++++
 qapi/machine.json         |  4 ++--
 qapi/misc-target.json     | 22 +++++++++++++++++-----
 hw/i386/sgx.c             | 11 +++++++++--
 4 files changed, 41 insertions(+), 9 deletions(-)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index e21e07478f..47a594a3b6 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -264,6 +264,19 @@ accepted incorrect commands will return an error. Users should make sure that
 all arguments passed to ``device_add`` are consistent with the documented
 property types.
 
+``query-sgx`` return value member ``section-size`` (since 7.0)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+Member ``section-size`` in return value elements with meta-type ``uint64`` is
+deprecated.  Use ``sections`` instead.
+
+
+``query-sgx-capabilities`` return value member ``section-size`` (since 7.0)
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+Member ``section-size`` in return value elements with meta-type ``uint64`` is
+deprecated.  Use ``sections`` instead.
+
 System accelerators
 -------------------
 
diff --git a/qapi/machine.json b/qapi/machine.json
index b6a37e17c4..cf47cb63a9 100644
--- a/qapi/machine.json
+++ b/qapi/machine.json
@@ -1207,7 +1207,7 @@
 #
 # @memdev: memory backend linked with device
 #
-# @node: the numa node
+# @node: the numa node (Since: 7.0)
 #
 # Since: 6.2
 ##
@@ -1288,7 +1288,7 @@
 #
 # @memdev: memory backend linked with device
 #
-# @node: the numa node
+# @node: the numa node (Since: 7.0)
 #
 # Since: 6.2
 ##
diff --git a/qapi/misc-target.json b/qapi/misc-target.json
index 1022aa0184..4bc45d2474 100644
--- a/qapi/misc-target.json
+++ b/qapi/misc-target.json
@@ -344,9 +344,9 @@
 #
 # @node: the numa node
 #
-# @size: the size of epc section
+# @size: the size of EPC section
 #
-# Since: 6.2
+# Since: 7.0
 ##
 { 'struct': 'SGXEPCSection',
   'data': { 'node': 'int',
@@ -365,7 +365,13 @@
 #
 # @flc: true if FLC is supported
 #
-# @sections: The EPC sections info for guest
+# @section-size: The EPC section size for guest
+#                Redundant with @sections.  Just for backward compatibility.
+#
+# @sections: The EPC sections info for guest (Since: 7.0)
+#
+# Features:
+# @deprecated: Member @section-size is deprecated.  Use @sections instead.
 #
 # Since: 6.2
 ##
@@ -374,6 +380,8 @@
             'sgx1': 'bool',
             'sgx2': 'bool',
             'flc': 'bool',
+            'section-size': { 'type': 'uint64',
+                    'features': [ 'deprecated' ] },
             'sections': ['SGXEPCSection']},
    'if': 'TARGET_I386' }
 
@@ -390,7 +398,9 @@
 #
 # -> { "execute": "query-sgx" }
 # <- { "return": { "sgx": true, "sgx1" : true, "sgx2" : true,
-#                  "flc": true, "section-size" : 0 } }
+#                  "flc": true,  "section-size" : 96468992,
+#                  "sections": [{"node": 0, "size": 67108864},
+#                  {"node": 1, "size": 29360128}]} }
 #
 ##
 { 'command': 'query-sgx', 'returns': 'SGXInfo', 'if': 'TARGET_I386' }
@@ -408,7 +418,9 @@
 #
 # -> { "execute": "query-sgx-capabilities" }
 # <- { "return": { "sgx": true, "sgx1" : true, "sgx2" : true,
-#                  "flc": true, "section-size" : 0 } }
+#                  "flc": true, "section-size" : 96468992,
+#                  "section" : [{"node": 0, "size": 67108864},
+#                  {"node": 1, "size": 29360128}]} }
 #
 ##
 { 'command': 'query-sgx-capabilities', 'returns': 'SGXInfo', 'if': 'TARGET_I386' }
diff --git a/hw/i386/sgx.c b/hw/i386/sgx.c
index 5de5dd0893..a2b318dd93 100644
--- a/hw/i386/sgx.c
+++ b/hw/i386/sgx.c
@@ -83,7 +83,7 @@ static uint64_t sgx_calc_section_metric(uint64_t low, uint64_t high)
            ((high & MAKE_64BIT_MASK(0, 20)) << 32);
 }
 
-static SGXEPCSectionList *sgx_calc_host_epc_sections(void)
+static SGXEPCSectionList *sgx_calc_host_epc_sections(uint64_t *size)
 {
     SGXEPCSectionList *head = NULL, **tail = &head;
     SGXEPCSection *section;
@@ -106,6 +106,7 @@ static SGXEPCSectionList *sgx_calc_host_epc_sections(void)
         section = g_new0(SGXEPCSection, 1);
         section->node = j++;
         section->size = sgx_calc_section_metric(ecx, edx);
+        *size += section->size;
         QAPI_LIST_APPEND(tail, section);
     }
 
@@ -156,6 +157,7 @@ SGXInfo *qmp_query_sgx_capabilities(Error **errp)
 {
     SGXInfo *info = NULL;
     uint32_t eax, ebx, ecx, edx;
+    uint64_t size = 0;
 
     int fd = qemu_open_old("/dev/sgx_vepc", O_RDWR);
     if (fd < 0) {
@@ -173,7 +175,8 @@ SGXInfo *qmp_query_sgx_capabilities(Error **errp)
     info->sgx1 = eax & (1U << 0) ? true : false;
     info->sgx2 = eax & (1U << 1) ? true : false;
 
-    info->sections = sgx_calc_host_epc_sections();
+    info->sections = sgx_calc_host_epc_sections(&size);
+    info->section_size = size;
 
     close(fd);
 
@@ -220,12 +223,14 @@ SGXInfo *qmp_query_sgx(Error **errp)
         return NULL;
     }
 
+    SGXEPCState *sgx_epc = &pcms->sgx_epc;
     info = g_new0(SGXInfo, 1);
 
     info->sgx = true;
     info->sgx1 = true;
     info->sgx2 = true;
     info->flc = true;
+    info->section_size = sgx_epc->size;
     info->sections = sgx_get_epc_sections_list();
 
     return info;
@@ -249,6 +254,8 @@ void hmp_info_sgx(Monitor *mon, const QDict *qdict)
                    info->sgx2 ? "enabled" : "disabled");
     monitor_printf(mon, "FLC support: %s\n",
                    info->flc ? "enabled" : "disabled");
+    monitor_printf(mon, "size: %" PRIu64 "\n",
+                   info->section_size);
 
     section_list = info->sections;
     for (section = section_list; section; section = section->next) {