[RFC PATCH v3 12/36] i386/tdx: Add property sept-ve-disable for tdx-guest object

[Xiaoyao Li <xiaoyao.li@xxxxxxxxx>]

Add sept-ve-disable property for tdx-guest object. It's used to
configure bit 28 of TD attributes.

Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
 qapi/qom.json         |  5 ++++-
 target/i386/kvm/tdx.c | 24 ++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/qapi/qom.json b/qapi/qom.json
index 1415ab22e531..fc380095a42c 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -792,10 +792,13 @@
 #
 # @attributes: TDX guest's attributes (default: 0)
 #
+# @sept-ve-disable: attributes.sept-ve-disable[bit 28] (default: 0)
+#
 # Since: 7.0
 ##
 { 'struct': 'TdxGuestProperties',
-  'data': { '*attributes': 'uint64' } }
+  'data': { '*attributes': 'uint64',
+            '*sept-ve-disable': 'bool' } }
 
 ##
 # @ObjectType:
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index a5cc187edbde..409526765304 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -21,6 +21,8 @@
 #include "kvm_i386.h"
 #include "tdx.h"
 
+#define TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE   BIT_ULL(28)
+
 static TdxGuest *tdx_guest;
 
 /* It's valid after kvm_confidential_guest_init()->kvm_tdx_init() */
@@ -196,6 +198,24 @@ out:
     return r;
 }
 
+static bool tdx_guest_get_sept_ve_disable(Object *obj, Error **errp)
+{
+    TdxGuest *tdx = TDX_GUEST(obj);
+
+    return !!(tdx->attributes & TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE);
+}
+
+static void tdx_guest_set_sept_ve_disable(Object *obj, bool value, Error **errp)
+{
+    TdxGuest *tdx = TDX_GUEST(obj);
+
+    if (value) {
+        tdx->attributes |= TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE;
+    } else {
+        tdx->attributes &= ~TDX_TD_ATTRIBUTES_SEPT_VE_DISABLE;
+    }
+}
+
 /* tdx guest */
 OBJECT_DEFINE_TYPE_WITH_INTERFACES(TdxGuest,
                                    tdx_guest,
@@ -211,6 +231,10 @@ static void tdx_guest_init(Object *obj)
     qemu_mutex_init(&tdx->lock);
 
     tdx->attributes = 0;
+
+    object_property_add_bool(obj, "sept-ve-disable",
+                             tdx_guest_get_sept_ve_disable,
+                             tdx_guest_set_sept_ve_disable);
 }
 
 static void tdx_guest_finalize(Object *obj)
-- 
2.27.0