i386/sev: Switch to use confidential_guest_kvm_init()

Use confidential_guest_kvm_init() instead of calling SEV
specific sev_kvm_init(). This allows the introduction of multiple
confidential-guest-support subclasses for different x86 vendors.

As a bonus, stubs are not needed anymore since there is no
direct call from target/i386/kvm/kvm.c to SEV code.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20240229060038.606591-1-xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

5 files changed, 69 insertions, 93 deletions

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f1b5901..c64b956 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -2543,10 +2543,12 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
      * mechanisms are supported in future (e.g. TDX), they'll need
      * their own initialization either here or elsewhere.
      */
-    ret = sev_kvm_init(ms->cgs, &local_err);
-    if (ret < 0) {
-        error_report_err(local_err);
-        return ret;
+    if (ms->cgs) {
+        ret = confidential_guest_kvm_init(ms->cgs, &local_err);
+        if (ret < 0) {
+            error_report_err(local_err);
+            return ret;
+        }
     }
 
     has_xcrs = kvm_check_extension(s, KVM_CAP_XCRS);
diff --git a/target/i386/kvm/meson.build b/target/i386/kvm/meson.build
index 84d9143..e785098 100644
--- a/target/i386/kvm/meson.build
+++ b/target/i386/kvm/meson.build
@@ -7,8 +7,6 @@ i386_kvm_ss.add(files(
 
 i386_kvm_ss.add(when: 'CONFIG_XEN_EMU', if_true: files('xen-emu.c'))
 
-i386_kvm_ss.add(when: 'CONFIG_SEV', if_false: files('sev-stub.c'))
-
 i386_system_ss.add(when: 'CONFIG_HYPERV', if_true: files('hyperv.c'), if_false: files('hyperv-stub.c'))
 
 i386_system_ss.add_all(when: 'CONFIG_KVM', if_true: i386_kvm_ss)
diff --git a/target/i386/kvm/sev-stub.c b/target/i386/kvm/sev-stub.c
deleted file mode 100644
index 1be5341..0000000
--- a/target/i386/kvm/sev-stub.c
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * QEMU SEV stub
- *
- * Copyright Advanced Micro Devices 2018
- *
- * Authors:
- *      Brijesh Singh <brijesh.singh@amd.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2 or later.
- * See the COPYING file in the top-level directory.
- *
- */
-
-#include "qemu/osdep.h"
-#include "sev.h"
-
-int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
-{
-    /* If we get here, cgs must be some non-SEV thing */
-    return 0;
-}
diff --git a/target/i386/sev.c b/target/i386/sev.c
index 72930ff..b8f79d3 100644
--- a/target/i386/sev.c
+++ b/target/i386/sev.c
@@ -353,63 +353,6 @@ static void sev_guest_set_kernel_hashes(Object *obj, bool value, Error **errp)
     sev->kernel_hashes = value;
 }
 
-static void
-sev_guest_class_init(ObjectClass *oc, void *data)
-{
-    object_class_property_add_str(oc, "sev-device",
-                                  sev_guest_get_sev_device,
-                                  sev_guest_set_sev_device);
-    object_class_property_set_description(oc, "sev-device",
-            "SEV device to use");
-    object_class_property_add_str(oc, "dh-cert-file",
-                                  sev_guest_get_dh_cert_file,
-                                  sev_guest_set_dh_cert_file);
-    object_class_property_set_description(oc, "dh-cert-file",
-            "guest owners DH certificate (encoded with base64)");
-    object_class_property_add_str(oc, "session-file",
-                                  sev_guest_get_session_file,
-                                  sev_guest_set_session_file);
-    object_class_property_set_description(oc, "session-file",
-            "guest owners session parameters (encoded with base64)");
-    object_class_property_add_bool(oc, "kernel-hashes",
-                                   sev_guest_get_kernel_hashes,
-                                   sev_guest_set_kernel_hashes);
-    object_class_property_set_description(oc, "kernel-hashes",
-            "add kernel hashes to guest firmware for measured Linux boot");
-}
-
-static void
-sev_guest_instance_init(Object *obj)
-{
-    SevGuestState *sev = SEV_GUEST(obj);
-
-    sev->sev_device = g_strdup(DEFAULT_SEV_DEVICE);
-    sev->policy = DEFAULT_GUEST_POLICY;
-    object_property_add_uint32_ptr(obj, "policy", &sev->policy,
-                                   OBJ_PROP_FLAG_READWRITE);
-    object_property_add_uint32_ptr(obj, "handle", &sev->handle,
-                                   OBJ_PROP_FLAG_READWRITE);
-    object_property_add_uint32_ptr(obj, "cbitpos", &sev->cbitpos,
-                                   OBJ_PROP_FLAG_READWRITE);
-    object_property_add_uint32_ptr(obj, "reduced-phys-bits",
-                                   &sev->reduced_phys_bits,
-                                   OBJ_PROP_FLAG_READWRITE);
-}
-
-/* sev guest info */
-static const TypeInfo sev_guest_info = {
-    .parent = TYPE_CONFIDENTIAL_GUEST_SUPPORT,
-    .name = TYPE_SEV_GUEST,
-    .instance_size = sizeof(SevGuestState),
-    .instance_finalize = sev_guest_finalize,
-    .class_init = sev_guest_class_init,
-    .instance_init = sev_guest_instance_init,
-    .interfaces = (InterfaceInfo[]) {
-        { TYPE_USER_CREATABLE },
-        { }
-    }
-};
-
 bool
 sev_enabled(void)
 {
@@ -906,20 +849,15 @@ sev_vm_state_change(void *opaque, bool running, RunState state)
     }
 }
 
-int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
+static int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp)
 {
-    SevGuestState *sev
-        = (SevGuestState *)object_dynamic_cast(OBJECT(cgs), TYPE_SEV_GUEST);
+    SevGuestState *sev = SEV_GUEST(cgs);
     char *devname;
     int ret, fw_error, cmd;
     uint32_t ebx;
     uint32_t host_cbitpos;
     struct sev_user_data_status status = {};
 
-    if (!sev) {
-        return 0;
-    }
-
     ret = ram_block_discard_disable(true);
     if (ret) {
         error_report("%s: cannot disable RAM discard", __func__);
@@ -1385,6 +1323,67 @@ bool sev_add_kernel_loader_hashes(SevKernelLoaderContext *ctx, Error **errp)
 }
 
 static void
+sev_guest_class_init(ObjectClass *oc, void *data)
+{
+    ConfidentialGuestSupportClass *klass = CONFIDENTIAL_GUEST_SUPPORT_CLASS(oc);
+
+    klass->kvm_init = sev_kvm_init;
+
+    object_class_property_add_str(oc, "sev-device",
+                                  sev_guest_get_sev_device,
+                                  sev_guest_set_sev_device);
+    object_class_property_set_description(oc, "sev-device",
+            "SEV device to use");
+    object_class_property_add_str(oc, "dh-cert-file",
+                                  sev_guest_get_dh_cert_file,
+                                  sev_guest_set_dh_cert_file);
+    object_class_property_set_description(oc, "dh-cert-file",
+            "guest owners DH certificate (encoded with base64)");
+    object_class_property_add_str(oc, "session-file",
+                                  sev_guest_get_session_file,
+                                  sev_guest_set_session_file);
+    object_class_property_set_description(oc, "session-file",
+            "guest owners session parameters (encoded with base64)");
+    object_class_property_add_bool(oc, "kernel-hashes",
+                                   sev_guest_get_kernel_hashes,
+                                   sev_guest_set_kernel_hashes);
+    object_class_property_set_description(oc, "kernel-hashes",
+            "add kernel hashes to guest firmware for measured Linux boot");
+}
+
+static void
+sev_guest_instance_init(Object *obj)
+{
+    SevGuestState *sev = SEV_GUEST(obj);
+
+    sev->sev_device = g_strdup(DEFAULT_SEV_DEVICE);
+    sev->policy = DEFAULT_GUEST_POLICY;
+    object_property_add_uint32_ptr(obj, "policy", &sev->policy,
+                                   OBJ_PROP_FLAG_READWRITE);
+    object_property_add_uint32_ptr(obj, "handle", &sev->handle,
+                                   OBJ_PROP_FLAG_READWRITE);
+    object_property_add_uint32_ptr(obj, "cbitpos", &sev->cbitpos,
+                                   OBJ_PROP_FLAG_READWRITE);
+    object_property_add_uint32_ptr(obj, "reduced-phys-bits",
+                                   &sev->reduced_phys_bits,
+                                   OBJ_PROP_FLAG_READWRITE);
+}
+
+/* sev guest info */
+static const TypeInfo sev_guest_info = {
+    .parent = TYPE_CONFIDENTIAL_GUEST_SUPPORT,
+    .name = TYPE_SEV_GUEST,
+    .instance_size = sizeof(SevGuestState),
+    .instance_finalize = sev_guest_finalize,
+    .class_init = sev_guest_class_init,
+    .instance_init = sev_guest_instance_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_USER_CREATABLE },
+        { }
+    }
+};
+
+static void
 sev_register_types(void)
 {
     type_register_static(&sev_guest_info);
diff --git a/target/i386/sev.h b/target/i386/sev.h
index e7499c9..9e10d09 100644
--- a/target/i386/sev.h
+++ b/target/i386/sev.h
@@ -57,6 +57,4 @@ int sev_inject_launch_secret(const char *hdr, const char *secret,
 int sev_es_save_reset_vector(void *flash_ptr, uint64_t flash_size);
 void sev_es_set_reset_vector(CPUState *cpu);
 
-int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp);
-
 #endif