target/mips: Honour -semihosting-config userspace=on

Honour the commandline -semihosting-config userspace=on option,
instead of always permitting userspace semihosting calls in system
emulation mode, by passing the correct value to the is_userspace
argument of semihosting_enabled().

Note that this is a behaviour change: if the user wants to
do semihosting calls from userspace they must now specifically
enable them on the command line.

MIPS semihosting is not implemented for linux-user builds.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20220822141230.3658237-5-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

4 files changed, 11 insertions, 10 deletions

diff --git a/target/mips/tcg/micromips_translate.c.inc b/target/mips/tcg/micromips_translate.c.inc
index b2c696f..632895c 100644
--- a/target/mips/tcg/micromips_translate.c.inc
+++ b/target/mips/tcg/micromips_translate.c.inc
@@ -825,7 +825,7 @@ static void gen_pool16c_insn(DisasContext *ctx)
         generate_exception_break(ctx, extract32(ctx->opcode, 0, 4));
         break;
     case SDBBP16:
-        if (is_uhi(extract32(ctx->opcode, 0, 4))) {
+        if (is_uhi(ctx, extract32(ctx->opcode, 0, 4))) {
             ctx->base.is_jmp = DISAS_SEMIHOST;
         } else {
             /*
@@ -941,7 +941,7 @@ static void gen_pool16c_r6_insn(DisasContext *ctx)
             break;
         case R6_SDBBP16:
             /* SDBBP16 */
-            if (is_uhi(extract32(ctx->opcode, 6, 4))) {
+            if (is_uhi(ctx, extract32(ctx->opcode, 6, 4))) {
                 ctx->base.is_jmp = DISAS_SEMIHOST;
             } else {
                 if (ctx->hflags & MIPS_HFLAG_SBRI) {
@@ -1310,7 +1310,7 @@ static void gen_pool32axf(CPUMIPSState *env, DisasContext *ctx, int rt, int rs)
             generate_exception_end(ctx, EXCP_SYSCALL);
             break;
         case SDBBP:
-            if (is_uhi(extract32(ctx->opcode, 16, 10))) {
+            if (is_uhi(ctx, extract32(ctx->opcode, 16, 10))) {
                 ctx->base.is_jmp = DISAS_SEMIHOST;
             } else {
                 check_insn(ctx, ISA_MIPS_R1);
diff --git a/target/mips/tcg/mips16e_translate.c.inc b/target/mips/tcg/mips16e_translate.c.inc
index 7568933..918b15d 100644
--- a/target/mips/tcg/mips16e_translate.c.inc
+++ b/target/mips/tcg/mips16e_translate.c.inc
@@ -951,7 +951,7 @@ static int decode_ase_mips16e(CPUMIPSState *env, DisasContext *ctx)
             }
             break;
         case RR_SDBBP:
-            if (is_uhi(extract32(ctx->opcode, 5, 6))) {
+            if (is_uhi(ctx, extract32(ctx->opcode, 5, 6))) {
                 ctx->base.is_jmp = DISAS_SEMIHOST;
             } else {
                 /*
diff --git a/target/mips/tcg/nanomips_translate.c.inc b/target/mips/tcg/nanomips_translate.c.inc
index b3aff22..812c111 100644
--- a/target/mips/tcg/nanomips_translate.c.inc
+++ b/target/mips/tcg/nanomips_translate.c.inc
@@ -3694,7 +3694,7 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx)
                 generate_exception_end(ctx, EXCP_BREAK);
                 break;
             case NM_SDBBP:
-                if (is_uhi(extract32(ctx->opcode, 0, 19))) {
+                if (is_uhi(ctx, extract32(ctx->opcode, 0, 19))) {
                     ctx->base.is_jmp = DISAS_SEMIHOST;
                 } else {
                     if (ctx->hflags & MIPS_HFLAG_SBRI) {
@@ -4633,7 +4633,7 @@ static int decode_isa_nanomips(CPUMIPSState *env, DisasContext *ctx)
                 generate_exception_end(ctx, EXCP_BREAK);
                 break;
             case NM_SDBBP16:
-                if (is_uhi(extract32(ctx->opcode, 0, 3))) {
+                if (is_uhi(ctx, extract32(ctx->opcode, 0, 3))) {
                     ctx->base.is_jmp = DISAS_SEMIHOST;
                 } else {
                     if (ctx->hflags & MIPS_HFLAG_SBRI) {
diff --git a/target/mips/tcg/translate.c b/target/mips/tcg/translate.c
index 0d936e2..c3f92ea 100644
--- a/target/mips/tcg/translate.c
+++ b/target/mips/tcg/translate.c
@@ -12082,12 +12082,13 @@ static void gen_cache_operation(DisasContext *ctx, uint32_t op, int base,
     tcg_temp_free_i32(t0);
 }
 
-static inline bool is_uhi(int sdbbp_code)
+static inline bool is_uhi(DisasContext *ctx, int sdbbp_code)
 {
 #ifdef CONFIG_USER_ONLY
     return false;
 #else
-    return semihosting_enabled() && sdbbp_code == 1;
+    bool is_user = (ctx->hflags & MIPS_HFLAG_KSU) == MIPS_HFLAG_UM;
+    return semihosting_enabled(is_user) && sdbbp_code == 1;
 #endif
 }
 
@@ -13898,7 +13899,7 @@ static void decode_opc_special_r6(CPUMIPSState *env, DisasContext *ctx)
         }
         break;
     case R6_OPC_SDBBP:
-        if (is_uhi(extract32(ctx->opcode, 6, 20))) {
+        if (is_uhi(ctx, extract32(ctx->opcode, 6, 20))) {
             ctx->base.is_jmp = DISAS_SEMIHOST;
         } else {
             if (ctx->hflags & MIPS_HFLAG_SBRI) {
@@ -14310,7 +14311,7 @@ static void decode_opc_special2_legacy(CPUMIPSState *env, DisasContext *ctx)
         gen_cl(ctx, op1, rd, rs);
         break;
     case OPC_SDBBP:
-        if (is_uhi(extract32(ctx->opcode, 6, 20))) {
+        if (is_uhi(ctx, extract32(ctx->opcode, 6, 20))) {
             ctx->base.is_jmp = DISAS_SEMIHOST;
         } else {
             /*