[PATCH v25 15/20] i386: split svm_helper into sysemu and stub-only user

From: Claudio Fontana <cfontana@suse.de>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Richard Henderson" <richard.henderson@linaro.org>,
	"Philippe Mathieu-Daudé" <philmd@redhat.com>,
	"Eduardo Habkost" <ehabkost@redhat.com>,
	"Peter Maydell" <peter.maydell@linaro.org>,
	"Alex Bennée" <alex.bennee@linaro.org>
Cc: Laurent Vivier <lvivier@redhat.com>,
	Thomas Huth <thuth@redhat.com>,
	Roman Bolshakov <r.bolshakov@yadro.com>,
	Claudio Fontana <cfontana@suse.de>,
	qemu-devel@nongnu.org
Subject: [PATCH v25 15/20] i386: split svm_helper into sysemu and stub-only user
Date: Fri, 26 Feb 2021 18:51:38 +0100	[thread overview]
Message-ID: <20210226175143.22388-16-cfontana@suse.de> (raw)
In-Reply-To: <20210226175143.22388-1-cfontana@suse.de>

For now we just copy over the previous user stubs, but really,

everything that requires s->cpl == 0 should be impossible
to trigger from user-mode emulation.

Later on we should add a check that asserts this easily f.e.:

static bool check_cpl0(DisasContext *s)
{
     int cpl = s->cpl;
 #ifdef CONFIG_USER_ONLY
     assert(cpl == 3);
 #endif
     if (cpl != 0) {
         gen_exception(s, EXCP0D_GPF, s->pc_start - s->cs_base);
         return false;
     }
     return true;
}

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/i386/tcg/{ => sysemu}/svm_helper.c | 62 +-----------------
 target/i386/tcg/user/svm_stubs.c          | 76 +++++++++++++++++++++++
 target/i386/tcg/meson.build               |  1 -
 target/i386/tcg/sysemu/meson.build        |  1 +
 target/i386/tcg/user/meson.build          |  1 +
 5 files changed, 80 insertions(+), 61 deletions(-)
 rename target/i386/tcg/{ => sysemu}/svm_helper.c (96%)
 create mode 100644 target/i386/tcg/user/svm_stubs.c

diff --git a/target/i386/tcg/svm_helper.c b/target/i386/tcg/sysemu/svm_helper.c
similarity index 96%
rename from target/i386/tcg/svm_helper.c
rename to target/i386/tcg/sysemu/svm_helper.c
index 097bb9b83d..5b9c6f18be 100644
--- a/target/i386/tcg/svm_helper.c
+++ b/target/i386/tcg/sysemu/svm_helper.c
@@ -1,5 +1,5 @@
 /*
- *  x86 SVM helpers
+ *  x86 SVM helpers (sysemu only)
  *
  *  Copyright (c) 2003 Fabrice Bellard
  *
@@ -22,66 +22,10 @@
 #include "exec/helper-proto.h"
 #include "exec/exec-all.h"
 #include "exec/cpu_ldst.h"
-#include "helper-tcg.h"
+#include "tcg/helper-tcg.h"
 
 /* Secure Virtual Machine helpers */
 
-#if defined(CONFIG_USER_ONLY)
-
-void helper_vmrun(CPUX86State *env, int aflag, int next_eip_addend)
-{
-}
-
-void helper_vmmcall(CPUX86State *env)
-{
-}
-
-void helper_vmload(CPUX86State *env, int aflag)
-{
-}
-
-void helper_vmsave(CPUX86State *env, int aflag)
-{
-}
-
-void helper_stgi(CPUX86State *env)
-{
-}
-
-void helper_clgi(CPUX86State *env)
-{
-}
-
-void helper_skinit(CPUX86State *env)
-{
-}
-
-void helper_invlpga(CPUX86State *env, int aflag)
-{
-}
-
-void cpu_vmexit(CPUX86State *nenv, uint32_t exit_code, uint64_t exit_info_1,
-                uintptr_t retaddr)
-{
-    assert(0);
-}
-
-void helper_svm_check_intercept_param(CPUX86State *env, uint32_t type,
-                                      uint64_t param)
-{
-}
-
-void cpu_svm_check_intercept_param(CPUX86State *env, uint32_t type,
-                                   uint64_t param, uintptr_t retaddr)
-{
-}
-
-void helper_svm_check_io(CPUX86State *env, uint32_t port, uint32_t param,
-                         uint32_t next_eip_addend)
-{
-}
-#else
-
 static inline void svm_save_seg(CPUX86State *env, hwaddr addr,
                                 const SegmentCache *sc)
 {
@@ -797,5 +741,3 @@ void do_vmexit(CPUX86State *env, uint32_t exit_code, uint64_t exit_info_1)
        host's code segment or non-canonical (in the case of long mode), a
        #GP fault is delivered inside the host. */
 }
-
-#endif
diff --git a/target/i386/tcg/user/svm_stubs.c b/target/i386/tcg/user/svm_stubs.c
new file mode 100644
index 0000000000..97528b56ad
--- /dev/null
+++ b/target/i386/tcg/user/svm_stubs.c
@@ -0,0 +1,76 @@
+/*
+ *  x86 SVM helpers (user-mode)
+ *
+ *  Copyright (c) 2003 Fabrice Bellard
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/helper-proto.h"
+#include "tcg/helper-tcg.h"
+
+void helper_vmrun(CPUX86State *env, int aflag, int next_eip_addend)
+{
+}
+
+void helper_vmmcall(CPUX86State *env)
+{
+}
+
+void helper_vmload(CPUX86State *env, int aflag)
+{
+}
+
+void helper_vmsave(CPUX86State *env, int aflag)
+{
+}
+
+void helper_stgi(CPUX86State *env)
+{
+}
+
+void helper_clgi(CPUX86State *env)
+{
+}
+
+void helper_skinit(CPUX86State *env)
+{
+}
+
+void helper_invlpga(CPUX86State *env, int aflag)
+{
+}
+
+void cpu_vmexit(CPUX86State *nenv, uint32_t exit_code, uint64_t exit_info_1,
+                uintptr_t retaddr)
+{
+    assert(0);
+}
+
+void helper_svm_check_intercept_param(CPUX86State *env, uint32_t type,
+                                      uint64_t param)
+{
+}
+
+void cpu_svm_check_intercept_param(CPUX86State *env, uint32_t type,
+                                   uint64_t param, uintptr_t retaddr)
+{
+}
+
+void helper_svm_check_io(CPUX86State *env, uint32_t port, uint32_t param,
+                         uint32_t next_eip_addend)
+{
+}
diff --git a/target/i386/tcg/meson.build b/target/i386/tcg/meson.build
index 449d9719ef..f9110e890c 100644
--- a/target/i386/tcg/meson.build
+++ b/target/i386/tcg/meson.build
@@ -8,7 +8,6 @@ i386_ss.add(when: 'CONFIG_TCG', if_true: files(
   'misc_helper.c',
   'mpx_helper.c',
   'seg_helper.c',
-  'svm_helper.c',
   'tcg-cpu.c',
   'translate.c'), if_false: files('tcg-stub.c'))
 
diff --git a/target/i386/tcg/sysemu/meson.build b/target/i386/tcg/sysemu/meson.build
index f84519a213..126528d0c9 100644
--- a/target/i386/tcg/sysemu/meson.build
+++ b/target/i386/tcg/sysemu/meson.build
@@ -5,4 +5,5 @@ i386_softmmu_ss.add(when: ['CONFIG_TCG', 'CONFIG_SOFTMMU'], if_true: files(
   'bpt_helper.c',
   'misc_helper.c',
   'fpu_helper.c',
+  'svm_helper.c',
 ))
diff --git a/target/i386/tcg/user/meson.build b/target/i386/tcg/user/meson.build
index 7d919d3bc8..f891cc8d76 100644
--- a/target/i386/tcg/user/meson.build
+++ b/target/i386/tcg/user/meson.build
@@ -2,4 +2,5 @@ i386_user_ss.add(when: ['CONFIG_TCG', 'CONFIG_USER_ONLY'], if_true: files(
   'excp_helper.c',
   'misc_stubs.c',
   'fpu_helper.c',
+  'svm_stubs.c',
 ))
-- 
2.26.2


