[PATCH v3 13/22] target/i386/sev: Remove stubs by using code elision

[Philippe Mathieu-Daudé]

Only declare sev_enabled() and sev_es_enabled() when CONFIG_SEV is
set, to allow the compiler to elide unused code. Remove unnecessary
stubs.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/sysemu/sev.h    | 14 +++++++++++++-
 target/i386/sev_i386.h  |  3 ---
 target/i386/cpu.c       | 16 +++++++++-------
 target/i386/sev-stub.c  | 36 ------------------------------------
 target/i386/meson.build |  2 +-
 5 files changed, 23 insertions(+), 48 deletions(-)
 delete mode 100644 target/i386/sev-stub.c

diff --git a/include/sysemu/sev.h b/include/sysemu/sev.h
index a329ed75c1c..f5c625bb3b3 100644
--- a/include/sysemu/sev.h
+++ b/include/sysemu/sev.h
@@ -14,9 +14,21 @@
 #ifndef QEMU_SEV_H
 #define QEMU_SEV_H
 
-#include "sysemu/kvm.h"
+#ifndef CONFIG_USER_ONLY
+#include CONFIG_DEVICES /* CONFIG_SEV */
+#endif
 
+#ifdef CONFIG_SEV
 bool sev_enabled(void);
+bool sev_es_enabled(void);
+#else
+#define sev_enabled() 0
+#define sev_es_enabled() 0
+#endif
+
+uint32_t sev_get_cbit_position(void);
+uint32_t sev_get_reduced_phys_bits(void);
+
 int sev_kvm_init(ConfidentialGuestSupport *cgs, Error **errp);
 
 #endif
diff --git a/target/i386/sev_i386.h b/target/i386/sev_i386.h
index 0798ab3519a..2d9a1a0112e 100644
--- a/target/i386/sev_i386.h
+++ b/target/i386/sev_i386.h
@@ -24,10 +24,7 @@
 #define SEV_POLICY_DOMAIN       0x10
 #define SEV_POLICY_SEV          0x20
 
-extern bool sev_es_enabled(void);
 extern SevInfo *sev_get_info(void);
-extern uint32_t sev_get_cbit_position(void);
-extern uint32_t sev_get_reduced_phys_bits(void);
 extern char *sev_get_launch_measurement(void);
 extern SevCapability *sev_get_capabilities(Error **errp);
 extern SevAttestationReport *
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index e169a01713d..27992bdc9f8 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -25,8 +25,8 @@
 #include "tcg/helper-tcg.h"
 #include "sysemu/reset.h"
 #include "sysemu/hvf.h"
+#include "sysemu/sev.h"
 #include "kvm/kvm_i386.h"
-#include "sev_i386.h"
 #include "qapi/error.h"
 #include "qapi/qapi-visit-machine.h"
 #include "qapi/qmp/qerror.h"
@@ -38,6 +38,7 @@
 #include "exec/address-spaces.h"
 #include "hw/boards.h"
 #include "hw/i386/sgx-epc.h"
+#include "sev_i386.h"
 #endif
 
 #include "disas/capstone.h"
@@ -5764,12 +5765,13 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
         *edx = 0;
         break;
     case 0x8000001F:
-        *eax = sev_enabled() ? 0x2 : 0;
-        *eax |= sev_es_enabled() ? 0x8 : 0;
-        *ebx = sev_get_cbit_position();
-        *ebx |= sev_get_reduced_phys_bits() << 6;
-        *ecx = 0;
-        *edx = 0;
+        *eax = *ebx = *ecx = *edx = 0;
+        if (sev_enabled()) {
+            *eax = 0x2;
+            *eax |= sev_es_enabled() ? 0x8 : 0;
+            *ebx = sev_get_cbit_position();
+            *ebx |= sev_get_reduced_phys_bits() << 6;
+        }
         break;
     default:
         /* reserved values: zero */
diff --git a/target/i386/sev-stub.c b/target/i386/sev-stub.c
deleted file mode 100644
index 8eae5d2fa8d..00000000000
--- a/target/i386/sev-stub.c
+++ /dev/null
@@ -1,36 +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 "qapi/error.h"
-#include "sev_i386.h"
-
-bool sev_enabled(void)
-{
-    return false;
-}
-
-uint32_t sev_get_cbit_position(void)
-{
-    return 0;
-}
-
-uint32_t sev_get_reduced_phys_bits(void)
-{
-    return 0;
-}
-
-bool sev_es_enabled(void)
-{
-    return false;
-}
diff --git a/target/i386/meson.build b/target/i386/meson.build
index a4f45c3ec1d..ae38dc95635 100644
--- a/target/i386/meson.build
+++ b/target/i386/meson.build
@@ -6,7 +6,7 @@
   'xsave_helper.c',
   'cpu-dump.c',
 ))
-i386_ss.add(when: 'CONFIG_SEV', if_true: files('host-cpu.c'), if_false: 
files('sev-stub.c'))
+i386_ss.add(when: 'CONFIG_SEV', if_true: files('host-cpu.c'))
 
 # x86 cpu type
 i386_ss.add(when: 'CONFIG_KVM', if_true: files('host-cpu.c'))
-- 
2.31.1