[Qemu-devel] [PATCH v5 5/7] target-arm: Add support for A32 and T32 HVC and SMC insns

[Peter Maydell]

Add support for HVC and SMC instructions to the A32 and
T32 decoder. Using these for real exceptions to EL2 or EL3
is currently not supported (the do_interrupt routine does
not handle them) but we require the instruction support to
implement PSCI.

Signed-off-by: Peter Maydell <address@hidden>
---
 target-arm/internals.h |  10 +++++
 target-arm/translate.c | 103 +++++++++++++++++++++++++++++++++++++++++++------
 target-arm/translate.h |   2 +
 3 files changed, 104 insertions(+), 11 deletions(-)

diff --git a/target-arm/internals.h b/target-arm/internals.h
index b7547bb..e46de71 100644
--- a/target-arm/internals.h
+++ b/target-arm/internals.h
@@ -236,6 +236,16 @@ static inline uint32_t syn_aa32_svc(uint32_t imm16, bool 
is_thumb)
         | (is_thumb ? 0 : ARM_EL_IL);
 }
 
+static inline uint32_t syn_aa32_hvc(uint32_t imm16)
+{
+    return (EC_AA32_HVC << ARM_EL_EC_SHIFT) | ARM_EL_IL | (imm16 & 0xffff);
+}
+
+static inline uint32_t syn_aa32_smc(void)
+{
+    return (EC_AA32_SMC << ARM_EL_EC_SHIFT) | ARM_EL_IL;
+}
+
 static inline uint32_t syn_aa64_bkpt(uint32_t imm16)
 {
     return (EC_AA64_BKPT << ARM_EL_EC_SHIFT) | ARM_EL_IL | (imm16 & 0xffff);
diff --git a/target-arm/translate.c b/target-arm/translate.c
index 8a2994f..4e764d3 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -941,6 +941,39 @@ static inline void gen_set_pc_im(DisasContext *s, 
target_ulong val)
     tcg_gen_movi_i32(cpu_R[15], val);
 }
 
+static inline void gen_hvc(DisasContext *s, int imm16)
+{
+    /* The pre HVC helper handles cases when HVC gets trapped
+     * as an undefined insn by runtime configuration (ie before
+     * the insn really executes).
+     */
+    gen_set_pc_im(s, s->pc - 4);
+    gen_helper_pre_hvc(cpu_env);
+    /* Otherwise we will treat this as a real exception which
+     * happens after execution of the insn. (The distinction matters
+     * for the PC value reported to the exception handler and also
+     * for single stepping.)
+     */
+    s->svc_imm = imm16;
+    gen_set_pc_im(s, s->pc);
+    s->is_jmp = DISAS_HVC;
+}
+
+static inline void gen_smc(DisasContext *s)
+{
+    /* As with HVC, we may take an exception either before or after
+     * the insn executes.
+     */
+    TCGv_i32 tmp;
+
+    gen_set_pc_im(s, s->pc - 4);
+    tmp = tcg_const_i32(syn_aa32_smc());
+    gen_helper_pre_smc(cpu_env, tmp);
+    tcg_temp_free_i32(tmp);
+    gen_set_pc_im(s, s->pc);
+    s->is_jmp = DISAS_SMC;
+}
+
 static inline void
 gen_set_condexec (DisasContext *s)
 {
@@ -7872,15 +7905,32 @@ static void disas_arm_insn(CPUARMState * env, 
DisasContext *s)
         case 7:
         {
             int imm16 = extract32(insn, 0, 4) | (extract32(insn, 8, 12) << 4);
-            /* SMC instruction (op1 == 3)
-               and undefined instructions (op1 == 0 || op1 == 2)
-               will trap */
-            if (op1 != 1) {
+            switch (op1) {
+            case 1:
+                /* bkpt */
+                ARCH(5);
+                gen_exception_insn(s, 4, EXCP_BKPT,
+                                   syn_aa32_bkpt(imm16, false));
+                break;
+            case 2:
+                /* Hypervisor call (v7) */
+                ARCH(7);
+                if (IS_USER(s)) {
+                    goto illegal_op;
+                }
+                gen_hvc(s, imm16);
+                break;
+            case 3:
+                /* Secure monitor call (v6+) */
+                ARCH(6K);
+                if (IS_USER(s)) {
+                    goto illegal_op;
+                }
+                gen_smc(s);
+                break;
+            default:
                 goto illegal_op;
             }
-            /* bkpt */
-            ARCH(5);
-            gen_exception_insn(s, 4, EXCP_BKPT, syn_aa32_bkpt(imm16, false));
             break;
         }
         case 0x8: /* signed multiply */
@@ -9710,10 +9760,23 @@ static int disas_thumb2_insn(CPUARMState *env, 
DisasContext *s, uint16_t insn_hw
                     goto illegal_op;
 
                 if (insn & (1 << 26)) {
-                    /* Secure monitor call (v6Z) */
-                    qemu_log_mask(LOG_UNIMP,
-                                  "arm: unimplemented secure monitor call\n");
-                    goto illegal_op; /* not implemented.  */
+                    if (!(insn & (1 << 20))) {
+                        /* Hypervisor call (v7) */
+                        int imm16 = extract32(insn, 16, 4) << 12
+                            | extract32(insn, 0, 12);
+                        ARCH(7);
+                        if (IS_USER(s)) {
+                            goto illegal_op;
+                        }
+                        gen_hvc(s, imm16);
+                    } else {
+                        /* Secure monitor call (v6+) */
+                        ARCH(6K);
+                        if (IS_USER(s)) {
+                            goto illegal_op;
+                        }
+                        gen_smc(s);
+                    }
                 } else {
                     op = (insn >> 20) & 7;
                     switch (op) {
@@ -11148,6 +11211,12 @@ static inline void 
gen_intermediate_code_internal(ARMCPU *cpu,
             if (dc->is_jmp == DISAS_SWI) {
                 gen_ss_advance(dc);
                 gen_exception(EXCP_SWI, syn_aa32_svc(dc->svc_imm, dc->thumb));
+            } else if (dc->is_jmp == DISAS_HVC) {
+                gen_ss_advance(dc);
+                gen_exception(EXCP_HVC, syn_aa32_hvc(dc->svc_imm));
+            } else if (dc->is_jmp == DISAS_SMC) {
+                gen_ss_advance(dc);
+                gen_exception(EXCP_SMC, syn_aa32_smc());
             } else if (dc->ss_active) {
                 gen_step_complete_exception(dc);
             } else {
@@ -11163,6 +11232,12 @@ static inline void 
gen_intermediate_code_internal(ARMCPU *cpu,
         if (dc->is_jmp == DISAS_SWI && !dc->condjmp) {
             gen_ss_advance(dc);
             gen_exception(EXCP_SWI, syn_aa32_svc(dc->svc_imm, dc->thumb));
+        } else if (dc->is_jmp == DISAS_HVC && !dc->condjmp) {
+            gen_ss_advance(dc);
+            gen_exception(EXCP_HVC, syn_aa32_hvc(dc->svc_imm));
+        } else if (dc->is_jmp == DISAS_SMC && !dc->condjmp) {
+            gen_ss_advance(dc);
+            gen_exception(EXCP_SMC, syn_aa32_smc());
         } else if (dc->ss_active) {
             gen_step_complete_exception(dc);
         } else {
@@ -11202,6 +11277,12 @@ static inline void 
gen_intermediate_code_internal(ARMCPU *cpu,
         case DISAS_SWI:
             gen_exception(EXCP_SWI, syn_aa32_svc(dc->svc_imm, dc->thumb));
             break;
+        case DISAS_HVC:
+            gen_exception(EXCP_HVC, syn_aa32_hvc(dc->svc_imm));
+            break;
+        case DISAS_SMC:
+            gen_exception(EXCP_SMC, syn_aa32_smc());
+            break;
         }
         if (dc->condjmp) {
             gen_set_label(dc->condlabel);
diff --git a/target-arm/translate.h b/target-arm/translate.h
index 85c6f9d..83fbf38 100644
--- a/target-arm/translate.h
+++ b/target-arm/translate.h
@@ -84,6 +84,8 @@ static inline int get_mem_index(DisasContext *s)
 #define DISAS_EXC 6
 /* WFE */
 #define DISAS_WFE 7
+#define DISAS_HVC 8
+#define DISAS_SMC 9
 
 #ifdef TARGET_AARCH64
 void a64_translate_init(void);
-- 
1.9.1