i386: split smm helper (sysemu)

smm is only really useful for sysemu, split in two modules
around the CONFIG_USER_ONLY, in order to remove the ifdef
and use the build system instead.

add cpu_abort() when detecting attempts to enter SMM mode via
SMI interrupt in user-mode, and assert that the cpu is not
in SMM mode while translating RSM instructions.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210322132800.7470-12-cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

6 files changed, 16 insertions, 18 deletions

diff --git a/target/i386/helper.h b/target/i386/helper.h
index c2ae2f7..8ffda4c 100644
--- a/target/i386/helper.h
+++ b/target/i386/helper.h
@@ -70,7 +70,11 @@ DEF_HELPER_1(clac, void, env)
 DEF_HELPER_1(stac, void, env)
 DEF_HELPER_3(boundw, void, env, tl, int)
 DEF_HELPER_3(boundl, void, env, tl, int)
+
+#ifndef CONFIG_USER_ONLY
 DEF_HELPER_1(rsm, void, env)
+#endif /* !CONFIG_USER_ONLY */
+
 DEF_HELPER_2(into, void, env, int)
 DEF_HELPER_2(cmpxchg8b_unlocked, void, env, tl)
 DEF_HELPER_2(cmpxchg8b, void, env, tl)
diff --git a/target/i386/tcg/meson.build b/target/i386/tcg/meson.build
index 320bcd1..449d971 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',
-  'smm_helper.c',
   'svm_helper.c',
   'tcg-cpu.c',
   'translate.c'), if_false: files('tcg-stub.c'))
diff --git a/target/i386/tcg/seg_helper.c b/target/i386/tcg/seg_helper.c
index d180a38..b6230eb 100644
--- a/target/i386/tcg/seg_helper.c
+++ b/target/i386/tcg/seg_helper.c
@@ -1351,7 +1351,11 @@ bool x86_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
     case CPU_INTERRUPT_SMI:
         cpu_svm_check_intercept_param(env, SVM_EXIT_SMI, 0, 0);
         cs->interrupt_request &= ~CPU_INTERRUPT_SMI;
+#ifdef CONFIG_USER_ONLY
+        cpu_abort(CPU(cpu), "SMI interrupt: cannot enter SMM in user-mode");
+#else
         do_smm_enter(cpu);
+#endif /* CONFIG_USER_ONLY */
         break;
     case CPU_INTERRUPT_NMI:
         cpu_svm_check_intercept_param(env, SVM_EXIT_NMI, 0, 0);
diff --git a/target/i386/tcg/sysemu/meson.build b/target/i386/tcg/sysemu/meson.build
index 4ab30cc..35ba16d 100644
--- a/target/i386/tcg/sysemu/meson.build
+++ b/target/i386/tcg/sysemu/meson.build
@@ -1,3 +1,4 @@
 i386_softmmu_ss.add(when: ['CONFIG_TCG', 'CONFIG_SOFTMMU'], if_true: files(
   'tcg-cpu.c',
+  'smm_helper.c',
 ))
diff --git a/target/i386/tcg/smm_helper.c b/target/i386/tcg/sysemu/smm_helper.c
index 62d027a..a45b565 100644
--- a/target/i386/tcg/smm_helper.c
+++ b/target/i386/tcg/sysemu/smm_helper.c
@@ -1,5 +1,5 @@
 /*
- *  x86 SMM helpers
+ *  x86 SMM helpers (sysemu-only)
  *
  *  Copyright (c) 2003 Fabrice Bellard
  *
@@ -18,27 +18,14 @@
  */
 
 #include "qemu/osdep.h"
-#include "qemu/main-loop.h"
 #include "cpu.h"
 #include "exec/helper-proto.h"
 #include "exec/log.h"
-#include "helper-tcg.h"
+#include "tcg/helper-tcg.h"
 
 
 /* SMM support */
 
-#if defined(CONFIG_USER_ONLY)
-
-void do_smm_enter(X86CPU *cpu)
-{
-}
-
-void helper_rsm(CPUX86State *env)
-{
-}
-
-#else
-
 #ifdef TARGET_X86_64
 #define SMM_REVISION_ID 0x00020064
 #else
@@ -330,5 +317,3 @@ void helper_rsm(CPUX86State *env)
     qemu_log_mask(CPU_LOG_INT, "SMM: after RSM\n");
     log_cpu_state_mask(CPU_LOG_INT, CPU(cpu), CPU_DUMP_CCOP);
 }
-
-#endif /* !CONFIG_USER_ONLY */
diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 880bc45..b02bdf5 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -8325,9 +8325,14 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
         gen_svm_check_intercept(s, pc_start, SVM_EXIT_RSM);
         if (!(s->flags & HF_SMM_MASK))
             goto illegal_op;
+#ifdef CONFIG_USER_ONLY
+        /* we should not be in SMM mode */
+        g_assert_not_reached();
+#else
         gen_update_cc_op(s);
         gen_jmp_im(s, s->pc - s->cs_base);
         gen_helper_rsm(cpu_env);
+#endif /* CONFIG_USER_ONLY */
         gen_eob(s);
         break;
     case 0x1b8: /* SSE4.2 popcnt */