From 5d2238896af628fc3f01dbe73be06fdd5603dedd Mon Sep 17 00:00:00 2001
From: Richard Henderson <richard.henderson@linaro.org>
Date: Fri, 14 May 2021 10:13:22 -0500
Subject: [PATCH] target/i386: Assert !SVME for user-only

Most of the VMM instructions are already disabled for user-only,
by being usable only from ring 0.

The spec is intentionally loose for VMMCALL, allowing the VMM to
define syscalls for user-only.  However, we're not emulating any
VMM, so VMMCALL can just raise #UD unconditionally.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210514151342.384376-31-richard.henderson@linaro.org>
---
 target/i386/tcg/translate.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c
index 28eb0e8adf0c..235caa247b48 100644
--- a/target/i386/tcg/translate.c
+++ b/target/i386/tcg/translate.c
@@ -138,10 +138,12 @@ typedef struct DisasContext {
 #define PE(S)     true
 #define CPL(S)    3
 #define IOPL(S)   0
+#define SVME(S)   false
 #else
 #define PE(S)     (((S)->flags & HF_PE_MASK) != 0)
 #define CPL(S)    ((S)->cpl)
 #define IOPL(S)   ((S)->iopl)
+#define SVME(S)   (((S)->flags & HF_SVME_MASK) != 0)
 #endif
 #if defined(CONFIG_USER_ONLY) && defined(TARGET_X86_64)
 #define VM86(S)   false
@@ -7495,7 +7497,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
             break;
 
         case 0xd8: /* VMRUN */
-            if (!(s->flags & HF_SVME_MASK) || !PE(s)) {
+            if (!SVME(s) || !PE(s)) {
                 goto illegal_op;
             }
             if (!check_cpl0(s)) {
@@ -7510,7 +7512,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
             break;
 
         case 0xd9: /* VMMCALL */
-            if (!(s->flags & HF_SVME_MASK)) {
+            if (!SVME(s)) {
                 goto illegal_op;
             }
             gen_update_cc_op(s);
@@ -7519,7 +7521,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
             break;
 
         case 0xda: /* VMLOAD */
-            if (!(s->flags & HF_SVME_MASK) || !PE(s)) {
+            if (!SVME(s) || !PE(s)) {
                 goto illegal_op;
             }
             if (!check_cpl0(s)) {
@@ -7531,7 +7533,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
             break;
 
         case 0xdb: /* VMSAVE */
-            if (!(s->flags & HF_SVME_MASK) || !PE(s)) {
+            if (!SVME(s) || !PE(s)) {
                 goto illegal_op;
             }
             if (!check_cpl0(s)) {
@@ -7543,8 +7545,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
             break;
 
         case 0xdc: /* STGI */
-            if ((!(s->flags & HF_SVME_MASK)
-                   && !(s->cpuid_ext3_features & CPUID_EXT3_SKINIT))
+            if ((!SVME(s) && !(s->cpuid_ext3_features & CPUID_EXT3_SKINIT))
                 || !PE(s)) {
                 goto illegal_op;
             }
@@ -7558,7 +7559,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
             break;
 
         case 0xdd: /* CLGI */
-            if (!(s->flags & HF_SVME_MASK) || !PE(s)) {
+            if (!SVME(s) || !PE(s)) {
                 goto illegal_op;
             }
             if (!check_cpl0(s)) {
@@ -7570,8 +7571,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
             break;
 
         case 0xde: /* SKINIT */
-            if ((!(s->flags & HF_SVME_MASK)
-                 && !(s->cpuid_ext3_features & CPUID_EXT3_SKINIT))
+            if ((!SVME(s) && !(s->cpuid_ext3_features & CPUID_EXT3_SKINIT))
                 || !PE(s)) {
                 goto illegal_op;
             }
@@ -7581,7 +7581,7 @@ static target_ulong disas_insn(DisasContext *s, CPUState *cpu)
             break;
 
         case 0xdf: /* INVLPGA */
-            if (!(s->flags & HF_SVME_MASK) || !PE(s)) {
+            if (!SVME(s) || !PE(s)) {
                 goto illegal_op;
             }
             if (!check_cpl0(s)) {
@@ -8516,6 +8516,7 @@ static void i386_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cpu)
     g_assert(SS32(dc) == ((flags & HF_SS32_MASK) != 0));
     g_assert(LMA(dc) == ((flags & HF_LMA_MASK) != 0));
     g_assert(ADDSEG(dc) == ((flags & HF_ADDSEG_MASK) != 0));
+    g_assert(SVME(dc) == ((flags & HF_SVME_MASK) != 0));
 
     dc->cc_op = CC_OP_DYNAMIC;
     dc->cc_op_dirty = false;