qapi: Cleanup SGX related comments and restore @section-size

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>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220120223104.437161-1-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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
 -------------------
 

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) {

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
 ##

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' }